 United States Court of Appeals
         FOR THE DISTRICT OF COLUMBIA CIRCUIT



Argued October 19, 2016               Decided March 16, 2018

                        No. 15-1211

               ACA INTERNATIONAL, ET AL.,
                     PETITIONERS

                             v.

   FEDERAL COMMUNICATIONS COMMISSION AND UNITED
               STATES OF AMERICA,
                  RESPONDENTS

        CAVALRY PORTFOLIO SERVICES, LLC, ET AL.,
                    INTERVENORS


  Consolidated with 15-1218, 15-1244, 15-1290, 15-1304,
  15-1306, 15-1311, 15-1313, 15-1314, 15-1440, 15-1441


           On Petitions for Review of an Order of
          the Federal Communications Commission


     Shay Dvoretzky argued the cause for petitioners ACA
International, et al. With him on the joint briefs were Helgi
C. Walker, Monica S. Desai, Amy L. Brown, Jonathan Jacob
Nadler, Christopher J. Wright, Jennifer P. Bagg, Elizabeth
Austin Bonner, Robert A. Long, Yaron Dori, Brian Melendez,
Tonia Ouellette Klausner, Keith E. Eggleton, Kate Comerford
                               2
Todd, Steven P. Lehotsky, and Warren Postman. Lindsay S.
See entered an appearance.

     Charles R. Messer, pro se, was on the brief for amicus
curiae Charles R. Messer in support of ACA International=s
petition.

   Paul Werner argued the cause for petitioner Rite Aid
Hdqtrs. Corp. With him on the briefs was Brian Weimer.

    Thomas C. Mugavero, Steven A. Augustino, Jonathan E.
Paikin, Jonathan G. Cedarbaum, Blaine C. Kimrey, and
Bryan K. Clark were on the joint briefs for intervenors MRS
BPO LLC, et al. in support of petitioners.

     Don L. Bell, II was on the brief for amicus curiae The
National Association of Chain Drug Stores, Inc. in support of
petitioner Rite Aid Hdqtrs. Corp.

     H. Russell Frisby, Jr., Harvey L. Reiter, Aryeh Fishman,
Michael Murray, and Jay Morrison were on the brief for
amici curiae American Gas Association, et al. in support of
petitioners.

    Charles H. Kennedy was on the brief for amici curiae
The American Bankers Association, Credit Union National
Association and The Independent Community Bankers of
America in support of petitioners.

    Andrew B. Clubok, Susan E. Engel, and Devin S.
Anderson were on the brief for amicus curiae The Internet
Association in support of petitioners.

     Joseph R. Palmore and Seth W. Lloyd were on the brief
for amici curiae Retail Litigation Center, Inc., National Retail
                             3
Federation, and National Restaurant Association in support of
petitioners.

     Bryan N. Tramont and Russell P. Hanser were on the
brief for amicus curiae CTIA-The Wireless Association in
support of petitioners.

    Eric J. Troutman was on the brief for amici curiae
American Financial Services Association, Consumer
Mortgage Coalition, and Mortgage Bankers Association in
support of petitioners. Jan T. Chilton and Kerry W. Frarnich
entered appearances.

   Amy M. Gallegos was on the brief for amicus curiae
Communication Innovators in support of petitioners.

    Scott M. Noveck, Counsel, Federal Communications
Commission, argued the cause for respondents. With him on
the brief were William J. Baer, Assistant Attorney General,
U.S. Department of Justice, Kristen C. Limarzi, Steven J.
Mintz, Attorneys, Jonathan B. Sallet, General Counsel,
Federal Communications Commission, David M. Gossett,
Deputy General Counsel, and Jacob M. Lewis, Associate
General Counsel.

     Craig L. Briskin and Julie Nepveu were on the brief for
amici curiae National Consumer Law Center, et al. in support
of the Federal Communications Commission 2015 Omnibus
Declaratory Ruling and Order.

    Marc Rotenberg and Alan Butler were on the brief for
amici curiae Electronic Privacy Information Center (EPIC)
and Six Consumer Privacy Organizations in support of
respondents.
                               4
   Before: SRINIVASAN and PILLARD, Circuit Judges, and
EDWARDS, Senior Circuit Judge.

    Opinion for the Court filed by Circuit Judge SRINIVASAN.

     SRINIVASAN, Circuit Judge: Unwanted robocalls are an
all-too-familiar phenomenon. For years, consumers have
complained to the Federal Communications Commission
about automated telemarketing calls and text messages that
they did not seek and cannot seem to stop.

     Congress sought to address consumers’ concerns with
undesired robocalls in the Telephone Consumer Protection
Act of 1991. The TCPA generally prohibits the use of certain
kinds of automated dialing equipment to call wireless
telephone numbers absent advance consent. The Act vests the
Commission with authority to implement those restrictions.

     In this case, a number of regulated entities seek review of
a 2015 order in which the Commission sought to clarify
various aspects of the TCPA’s general bar against using
automated dialing devices to make uninvited calls. The
challenges encompass four issues addressed by the agency’s
order: (i) which sorts of automated dialing equipment are
subject to the TCPA’s restrictions on unconsented calls; (ii)
when a caller obtains a party’s consent, does a call
nonetheless violate the Act if, unbeknownst to the caller, the
consenting party’s wireless number has been reassigned to a
different person who has not given consent; (iii) how may a
consenting party revoke her consent; and (iv) did the
Commission too narrowly fashion an exemption from the
TCPA’s consent requirement for certain healthcare-related
calls.
                              5
     We uphold the Commission’s approach to revocation of
consent, under which a party may revoke her consent through
any reasonable means clearly expressing a desire to receive
no further messages from the caller. We also sustain the
scope of the agency’s exemption for time-sensitive healthcare
calls.

     We set aside, however, the Commission’s effort to clarify
the types of calling equipment that fall within the TCPA’s
restrictions. The Commission’s understanding would appear
to subject ordinary calls from any conventional smartphone to
the Act’s coverage, an unreasonably expansive interpretation
of the statute. We also vacate the agency’s approach to calls
made to a phone number previously assigned to a person who
had given consent but since reassigned to another
(nonconsenting) person. The Commission concluded that
calls in that situation violate the TCPA, apart from a one-call
safe harbor, regardless of whether the caller has any
awareness of the reassignment. We determine that the
agency’s one-call safe harbor, at least as defended in the
order, is arbitrary and capricious.

    We therefore grant the petitions for review in part and
deny them in part.

                              I.

    The federal government’s efforts to combat unwanted
robocalls have spanned nearly three decades, involving two
federal agencies and a number of congressional enactments.
In the Telemarketing and Consumer Fraud and Abuse
Prevention Act of 1994, 15 U.S.C. § 6101 et seq., Congress
empowered the Federal Trade Commission to regulate the
telemarketing industry. The FTC’s measures include a
general bar against calling any telephone number on the “do-
                               6
not-call registry” without consent or an established business
relationship. 16 C.F.R. § 310.4(b)(1)(iii)(B); see 15 U.S.C.
§ 6151(a). This case does not concern the FTC’s initiatives.

     This case instead concerns the Federal Communications
Commission’s efforts to combat unwanted robocalls pursuant
to its authority under the TCPA. Some of the Commission’s
restrictions on telemarketing calls mirror measures established
by the FTC. Compare 16 C.F.R. §§ 310.4(b)(1)(iii)(B),
310.4(c), with 47 C.F.R. § 64.1200(c). But the agencies’
initiatives also differ in various respects. Of relevance here,
only the TCPA specifically restricts the use of an “automatic
telephone dialing system” to make calls.            47 U.S.C.
§ 227(b)(1)(A). Petitioners challenge the Commission’s
interpretation and implementation of various TCPA
provisions pertaining to automated dialing equipment.

                               A.

     Congress enacted the TCPA in 1991 based on findings
that the “use of the telephone to market goods and services to
the home and other businesses” had become “pervasive due to
the increased use of cost-effective telemarketing techniques.”
47 U.S.C. § 227 note, Pub. L. No. 102-243, § 2(1), 105 Stat.
2394, 2394. “Many consumers,” Congress determined, “are
outraged over the proliferation of intrusive, nuisance calls to
their homes from telemarketers.” Id. § 2(6)-(7).

       The TCPA restricts calls both “to any residential
telephone line” and to “any telephone number assigned to a
. . . cellular telephone service.” 47 U.S.C. § 227(b)(1)(A)(iii),
(B). This case solely concerns the latter restrictions on
telephone calls to wireless numbers.
                               7
     Congress, in that regard, made it “unlawful . . . to make
any call (other than a call made for emergency purposes or
made with the prior express consent of the called party) using
any automatic telephone dialing system . . . to any telephone
number assigned to a . . . cellular telephone service,” “unless
such call is made solely to collect a debt owed to or
guaranteed by the United States.” Id. § 227(b)(1)(A)(iii).
The statute defines an “automatic telephone dialing system”
(ATDS, or autodialer) as “equipment which has the
capacity—(A) to store or produce telephone numbers to be
called, using a random or sequential number generator; and
(B) to dial such numbers.” Id. § 227(a)(1).

     In short, the TCPA generally makes it unlawful to call a
cell phone using an ATDS. And an ATDS is equipment with
the “capacity” to perform each of two enumerated functions:
(i) storing or producing telephone numbers “using a random
or sequential number generator” and (ii) dialing those
numbers. The general prohibition on autodialer calls to
wireless numbers is subject to three exceptions. The central
exception for purposes of this case is for calls made with
“prior express consent.” There are also exceptions for
emergency calls and calls made to collect government debts.

     The TCPA vests the Commission with responsibility to
promulgate regulations implementing the Act’s requirements.
Id. § 227(b)(2). The Act also grants the Commission specific
authority to fashion exemptions from the general prohibition
on autodialer calls to wireless numbers, where the calls are
“not charged to the called party.” Id. § 227(b)(2)(C). As
Congress explained, the FCC “should have the flexibility to
design different rules for those types of automated or
prerecorded calls that it finds are not considered a nuisance or
invasion of privacy.” Id. § 227 note, Pub. L. No. 102-243,
§ 2(13), 105 Stat. 2394, 2395.
                              8
     Since the TCPA’s enactment, the FCC has issued a series
of rulemakings and declaratory rulings addressing the Act’s
reach. In 2003, for instance, the agency concluded that the
statute’s restrictions on “mak[ing] any call” using an ATDS
encompass the sending of text messages. See In re Rules and
Regulations Implementing the Telephone Consumer
Protection Act of 1991 (2003 Order), 18 FCC Rcd. 14,014,
14,115 ¶ 165 (2003).

     The Act contains a private right of action permitting
aggrieved parties to recover at least $500 in damages for each
call made (or text message sent) in violation of the statute,
and up to treble damages for each “willful[] or knowing[]”
violation. 47 U.S.C. § 227(b)(3). There is no cap on the
amount of recoverable damages. The Commission has noted
a surge in TCPA lawsuits (including class actions) in recent
years, likely attributable in part to the “skyrocketing growth
of mobile phones.”           In re Rules and Regulations
Implementing the Telephone Consumer Protection Act of
1991 (2015 Declaratory Ruling), 30 FCC Rcd. 7961, 7970
¶¶ 6-7 (2015).

                             B.

     In a Declaratory Ruling and Order issued in 2015, the
Commission (with two Commissioners dissenting) addressed
21 separate petitions for rulemaking or requests for
clarification. In this court, petitioners and intervenors seek
review of four aspects of the Commission’s order.

     First, the Commission sought to clarify which devices for
making calls qualify as an ATDS—i.e., equipment that “has
the capacity” to “store or produce telephone numbers to be
called, using a random or sequential number generator,” and
“to dial such numbers.” 47 U.S.C. § 227(a)(1). With regard
                               9
to whether equipment has the “capacity” to perform the
enumerated functions, the Commission declined to define a
device’s “capacity” in a manner confined to its “present
capacity.”    Instead, the agency construed a device’s
“capacity” to encompass its “potential functionalities” with
modifications such as software changes. 2015 Declaratory
Ruling, 30 FCC Rcd. at 7974 ¶ 16.

     The Commission also addressed the precise functions that
a device must have the capacity to perform for it to be
considered an ATDS. The Commission reaffirmed prior
orders deciding that “predictive dialers”—equipment that can
dial automatically from a given list of telephone numbers
using algorithms to predict “when a sales agent will be
available”—qualify as autodialers. Id. at 7972 ¶ 10 & n.39.
The Commission further explained that a “basic function[]” of
an autodialer is to “dial numbers without human
intervention.” Id. at 7975 ¶ 17. At the same time, the
Commission also declined to “clarify[] that a dialer is not an
autodialer unless it has the capacity to dial numbers without
human intervention.” Id. at 7976 ¶ 20.

     Second, the Commission spoke to whether, and when, a
caller violates the TCPA by calling a wireless number that has
been reassigned from a consenting party to another person
without the caller’s knowledge. The Act specifically permits
autodialer calls “made with the prior express consent of the
called party.” 47 U.S.C. § 227(b)(1)(A). If the “called party”
for those purposes refers to the intended recipient of a call or
message, a caller would face no liability when using an ATDS
to call a number believed to belong to a consenting party,
even if the number in fact has been reassigned to another
person who has not consented.
                              10
     The Commission, though, determined that the term
“called party” refers not to “the intended recipient of a call”
but instead to “the current subscriber” (i.e., the current,
nonconsenting holder of a reassigned number rather than a
consenting party who previously held the number). 2015
Declaratory Ruling, 30 FCC Rcd. at 7999 ¶ 72. But the
Commission did not hold a caller strictly liable when unaware
that the consenting party’s number has been reassigned to
another person. Instead, the agency allowed one—and only
one—liability-free, post-reassignment call for callers who
lack “knowledge of [the] reassignment” and possess “a
reasonable basis to believe that they have valid consent.” Id.
at 8000 ¶ 72.

     Third, the Commission clarified the ways in which a
consenting party can revoke her consent to receive autodialer
calls.   The Commission decided that callers may not
unilaterally designate the acceptable means of revocation. It
also declined to prescribe its own set of mandatory revocation
procedures. Rather, it concluded that “a called party may
revoke consent at any time and through any reasonable
means”—whether orally or in writing—“that clearly
expresses a desire not to receive further messages.” Id. at
7989-90 ¶ 47; id. at 7996 ¶ 63.

     Fourth, and finally, the Commission exempted from the
autodialer provision’s consent requirement certain calls to
wireless numbers “for which there is exigency and that have a
healthcare treatment purpose.” Id. at 8031 ¶ 146. It declined,
however, to give the exemption the reach desired by certain
parties that are in the business of healthcare-related marketing
calls.

    We will take up the challenges to those four aspects of
the Commission’s 2015 ruling in the same order.
                              11
                              II.

     Under the Administrative Procedure Act, we assess
whether the Commission’s challenged actions in its 2015
order were “arbitrary, capricious, an abuse of discretion, or
otherwise not in accordance with law.” 5 U.S.C. § 706(2)(A).
We review the lawfulness of the Commission’s interpretations
of the TCPA using the two-step Chevron framework. That
inquiry calls for examining whether “Congress has directly
spoken to the precise question at issue,” and, if not, whether
“the agency’s answer is based on a permissible construction
of the statute.” Chevron U.S.A. Inc. v. Nat’l Res. Def.
Council, Inc., 467 U.S. 837, 842-43 (1984).

     To be lawful, the Commission’s challenged actions must
also satisfy the Administrative Procedure Act’s requirement
that they not be arbitrary or capricious. Arbitrary-and-
capricious review includes assuring that the agency “engaged
in reasoned decisionmaking.” Judulang v. Holder, 565 U.S.
42, 53 (2011). Review of agency action for arbitrariness and
capriciousness sometimes entails essentially the same inquiry
as review of an agency’s exercise of statutory interpretation
under Chevron’s second step. See id. at 52 n.7; Agape
Church, Inc. v. FCC, 738 F.3d 397, 410 (D.C. Cir. 2013).

     Applying those standards to petitioners’ four sets of
challenges to the Commission’s 2015 Declaratory Ruling, we
set aside the Commission’s explanation of which devices
qualify as an ATDS, as well as its understanding of when a
caller violates the Act by calling a wireless number previously
held by a consenting party but reassigned to a person who has
not given consent. We sustain, however, the Commission’s
ruling that a party can revoke consent through any reasonable
means clearly expressing a desire to receive no further calls or
                                12
texts, and we also uphold the scope of the Commission’s
exemption for time-sensitive, healthcare-related calls.

                                A.

     We first consider the Commission’s effort to clarify
which sorts of calling equipment qualify as an ATDS so as to
fall subject to the general prohibition against making calls
using such a device without consent. The statute defines an
ATDS as “equipment which has the capacity—(A) to store or
produce telephone numbers to be called, using a random or
sequential number generator; and (B) to dial such numbers.”
47 U.S.C § 227(a)(1). That definition naturally raises two
questions: (i) when does a device have the “capacity” to
perform the two enumerated functions; and (ii) what precisely
are those functions? We conclude that the Commission’s
approach to those two questions cannot be sustained, at least
given the Commission’s unchallenged assumption that a call
made with a device having the capacity to function as an
autodialer can violate the statute even if autodialer features
are not used to make the call.

                                1.

     a. In addressing what it means for equipment to have the
“capacity” to perform the autodialer functions enumerated in
the statute, the Commission rejected the arguments of various
parties that a device’s capacity must be measured solely by
reference to its “present capacity” or its “current
configuration” without any modification. 2015 Declaratory
Ruling, 30 FCC Rcd. at 7974 ¶ 16. The Commission instead
determined that the “capacity” of calling equipment “includes
its potential functionalities” or “future possibility,” not just its
“present ability.” Id. at 7974 ¶ 16; id. at 7975 ¶ 20.
                              13
     The Commission reasoned that the “functional capacity
of software-controlled equipment is designed to be flexible,
both in terms of features that can be activated or de-activated
and in terms of features that can be added to the equipment’s
overall functionality through software changes or updates.”
Id. at 7974 ¶ 16 n.63. And the Commission found support for
its “potential functionalities” approach in dictionary
definitions of the term “capacity,” one of which is “the
potential or suitability for holding, storing, or
accommodating.” Id. at 7975 ¶ 19 (quoting Capacity,
Merriam-Webster Dictionary Online, https://www.merriam-
webster.com/dictionary/capacity (as visited May 18, 2015)).

     In challenging the Commission’s approach, petitioners
argue that the term “capacity” in the statutory definition of an
ATDS can refer only to a device’s “present ability,” i.e., its
current and unmodified state, not its “potential ability” taking
into account possible upgrades or modifications. It is far from
clear, though, that labels such as “present” ability versus
“potential” ability should carry dispositive weight in assessing
the meaning of the statutory term “capacity.” After all, even
under the ostensibly narrower, “present ability” interpretation
advanced by petitioners, a device that “presently” (and
generally) operates as a traditional telephone would still be
considered have the “capacity” to function as an ATDS if it
could assume the requisite features merely upon touching a
button on the equipment to switch it into autodialer mode.
Virtually any understanding of “capacity” thus contemplates
some future functioning state, along with some modifying act
to bring that state about.

    Consequently, the question whether equipment has the
“capacity” to perform the functions of an ATDS ultimately
turns less on labels such as “present” and “potential” and
more on considerations such as how much is required to
                               14
enable the device to function as an autodialer: does it require
the simple flipping of a switch, or does it require essentially a
top-to-bottom reconstruction of the equipment?              And
depending on the answer, what kinds (and how broad a swath)
of telephone equipment might then be deemed to qualify as an
ATDS subject to the general bar against making any calls
without prior express consent?

     b.    Here, the Commission adopted an expansive
interpretation of “capacity” having the apparent effect of
embracing any and all smartphones: the device routinely used
by the vast majority of citizens to make calls and send
messages (and for many people, the sole phone equipment
they own). It is undisputed that essentially any smartphone,
with the addition of software, can gain the statutorily
enumerated features of an autodialer and thus function as an
ATDS. The Commission in its ruling did not question the
observation of a dissenting Commissioner that “[i]t’s trivial to
download an app, update software, or write a few lines of
code that would modify a phone to dial random or sequential
numbers.” 2015 Declaratory Ruling, 30 FCC Rcd. at 8075
(Comm’r Pai, dissenting). The Commission itself noted that
“[d]ialing options” are now “available via smartphone apps”
that enable “[c]alling and texting consumers en masse.” Id. at
7970 ¶ 7.

     The Commission’s ruling concluded that app downloads
and other software additions of that variety—and the
enhanced functionality they bring about—are appropriately
considered to be within a device’s “capacity.” The ruling
states that equipment’s “functional capacity” includes
“features that can be added . . . through software changes or
updates.” Id. at 7974 ¶ 16 n.63. As a result, “a piece of
equipment can possess the requisite ‘capacity’ to satisfy the
statutory definition of an ‘autodialer’ even if, for example, it
                              15
requires the addition of software to actually perform the
functions described in the definition.” Id. at 7975 ¶ 18. The
Commission reinforced the point in an example set forth in its
brief in this case: “If I ask whether the Firefox browser has
the ‘capacity’ to play Flash videos, it would be natural for you
to answer ‘Yes, if you download the Flash plug-in’—and it
would be incorrect for you to answer ‘No.’” FCC Br. 29.

    If a device’s “capacity” includes functions that could be
added through app downloads and software additions, and if
smartphone apps can introduce ATDS functionality into the
device, it follows that all smartphones, under the
Commission’s approach, meet the statutory definition of an
autodialer. The Commission’s ruling does not deny that
conclusion.

     To the contrary, a number of parties specifically argued
to the agency “that a broad interpretation of ‘capacity’ could
potentially sweep in smartphones because they may have the
capacity to store telephone numbers to be called and to dial
such numbers through the use of an app or other software.”
2015 Declaratory Ruling, 30 FCC Rcd. at 7976 ¶ 21. Rather
than resist that contention, the Commission assumed its
correctness, responding that, even if smartphones qualify as
autodialers, it was unclear to the Commission that the “typical
use of smartphones” would be “likely” to give rise to
“unwanted calls” of a kind producing “legal action.” Id. at
7977 ¶ 21. A dissenting Commissioner read that portion of
the Commission’s order to “acknowledge[] that smartphones
are swept in under its reading,” such that “each and every
smartphone . . . is an automatic telephone dialing system.” Id.
at 8075 & n.576 (Comm’r Pai, dissenting). The Commission
did not disagree or suggest otherwise.
                              16
     c. If every smartphone qualifies as an ATDS, the
statute’s restrictions on autodialer calls assume an eye-
popping sweep. Recall that the statute generally bars the use
of an ATDS to make any call (or send any text message)
without prior express consent, and tags each violation with a
minimum $500 penalty in damages for each individual
recipient of each prohibited call or message. The reach of the
statute becomes especially pronounced upon recognizing that,
under the Commission’s approach, an uninvited call or
message from a smartphone violates the statute even if
autodialer features were not used to make the call or send the
message. Id. at 7976 ¶ 19 n.70. We explore that interpretive
issue in greater depth below (infra § II.A.3); but for now, it
suffices to appreciate the Commission’s understanding that, as
long as equipment has the “capacity” to function as an
autodialer—as is true of every smartphone under the agency’s
view—any uninvited call or message from the device is a
statutory violation.

     Imagine, for instance, that a person wishes to send an
invitation for a social gathering to a person she recently met
for the first time. If she lacks prior express consent to send
the invitation, and if she obtains the acquaintance’s cell phone
number from a mutual friend, she ostensibly commits a
violation of federal law by calling or sending a text message
from her smartphone to extend the invitation. See 2015
Declaratory Ruling, 30 FCC Rcd. at 8076 (Comm’r Pai,
dissenting). And if she sends a group message inviting ten
people to the gathering, again without securing prior express
consent from any of the recipients, she not only would have
infringed the TCPA ten distinct times but would also face a
minimum damages recovery against her of $5,000.

    Those sorts of anomalous outcomes are bottomed in an
unreasonable, and impermissible, interpretation of the
                               17
statute’s reach. The TCPA cannot reasonably be read to
render every smartphone an ATDS subject to the Act’s
restrictions, such that every smartphone user violates federal
law whenever she makes a call or sends a text message
without advance consent.

     A “significant majority of American adults” owned a
smartphone even by 2013. Riley v. California, 134 S. Ct.
2473, 2484 (2014). And as of the end of 2016, nearly 80% of
American adults had become smartphone owners. See 10
Facts About Smartphones as the iPhone Turns 10, Pew
Research          Ctr.,        June         28,         2017,
http://www.pewresearch.org/fact-tank/2017/06/28/10-facts-
about-smartphones (last visited Dec. 18, 2017). That figure
will only continue to grow, and increasingly, individuals own
no phone equipment other than a smartphone. See id.;
Wireless Substitution: Early Release of Estimates From the
National Health Interview Survey, January–June 2017, Nat’l
Ctr.     for    Health    Statistics    1     (Dec.    2017),
https://www.cdc.gov/nchs/data/nhis/earlyrelease/wireless2017
05.pdf.

      It is untenable to construe the term “capacity” in the
statutory definition of an ATDS in a manner that brings
within the definition’s fold the most ubiquitous type of phone
equipment known, used countless times each day for routine
communications by the vast majority of people in the country.
It cannot be the case that every uninvited communication
from a smartphone infringes federal law, and that nearly every
American is a TCPA-violator-in-waiting, if not a violator-in-
fact.

     In that regard, it is notable that Congress, in its findings
setting forth the basis for the statute, found that some “30,000
businesses actively telemarket goods and services to business
                              18
and residential customers” and “[m]ore than 300,000
solicitors call more than 18,000,000 Americans every day.”
47 U.S.C. § 227 note, Pub. L. No. 102-243, § 2(2)-(3), 105
Stat. 2394, 2394. Those sorts of predicate congressional
findings can shed substantial light on the intended reach of a
statute. See Sutton v. United Airlines, Inc., 527 U.S. 471,
484-87 (1999).

     Of course, there is no expectation that a statute’s reach
necessarily will precisely match Congress’s findings about a
problem it aims to address, and Congress might well fashion a
statute’s operative provisions with built-in flexibility to
accommodate expansion of the concerns animating the
legislation over time. But a several-fold gulf between
congressional findings and a statute’s suggested reach can call
into doubt the permissibility of the interpretation in
consideration.

     That is what happened in Sutton. There, the Supreme
Court rejected an interpretation of the term “disability” in the
Americans with Disabilities Act that would have treated some
160 million persons as disabled in the face of congressional
findings contemplating the population of disabled persons as
numbering only 43 million. See id.; id. at 494-95 (Ginsburg,
J., concurring).    (After Sutton, Congress amended the
statutory findings and the statute to allow for an expansive
application. See ADA Amendments Act of 2008, Pub. L. No.
110-325, § 2, 122 Stat. 3553, 3554.)

     Here, as in Sutton, the Commission’s expansive
understanding of “capacity” in the TCPA is incompatible with
a statute grounded in concerns about hundreds of thousands of
“solicitors” making “telemarketing” calls on behalf of tens of
thousands of “businesses.” The Commission’s interpretation
would extend a law originally aimed to deal with hundreds of
                              19
thousands of telemarketers into one constraining hundreds of
millions of everyday callers.

    The Commission’s capacious understanding of a device’s
“capacity” lies considerably beyond the agency’s zone of
delegated authority for purposes of the Chevron framework.
As we have explained, “even if the [statute] does not
foreclose the Commission’s interpretation, the interpretation
[can] fall[] outside the bounds of reasonableness” at
Chevron’s second step. Goldstein v. SEC, 451 F.3d 873, 880-
81 (D.C. Cir. 2006). That is because an “agency[’s]
construction of a statute cannot survive judicial review if a
contested regulation reflects an action that exceeds the
agency’s authority.” Id. (quoting Aid Ass’n for Lutherans v.
United States Postal Serv., 321 F.3d 1166, 1174 (D.C. Cir.
2003)).

     In Aid Ass’n, for example, we examined Postal Service
regulations that excluded nonprofit organizations’ use of
certain reduced postage rates. We found the regulations to be
incompatible with congressional intent. The regulations, we
said, “constitute an impermissible construction of the statute
under Chevron Step Two because the interpretation is utterly
unreasonable in the breadth of its regulatory exclusion.” 321
F.3d at 1178.

     In this case, similarly, the Commission’s interpretation of
the term “capacity” in the statutory definition of an ATDS is
“utterly unreasonable in the breadth of its regulatory
[in]clusion.” Id. Nothing in the TCPA countenances
concluding that Congress could have contemplated the
applicability of the statute’s restrictions to the most
commonplace phone device used every day by the
overwhelming majority of Americans.
                              20
     The Commission suggested in its ruling that, unless
“capacity” reached so broadly, “little or no modern dialing
equipment would fit the statutory definition.”          2015
Declaratory Ruling, 30 FCC Rcd. at 7976 ¶ 20. But Congress
need not be presumed to have intended the term “automatic
telephone dialing system” to maintain its applicability to
modern phone equipment in perpetuity, regardless of
technological advances that may render the term increasingly
inapplicable over time. After all, the statute also generally
prohibits nonconsensual calls to numbers associated with a
“paging service” or “specialized mobile radio service,” 47
U.S.C. § 227(b)(1)(A)(iii), yet those terms have largely
ceased to have practical significance.

     In any event, the Commission retains a measure of
authority under the TCPA to fashion exemptions to the
restrictions on use of autodialers to call wireless numbers. Id.
§ 227(b)(2)(C). The agency presumably could, if needed,
fashion exemptions preventing a result under which every
uninvited call or message from a standard smartphone would
violate the statute.

     d. In its briefing before our court, the Commission now
submits that its order in fact did not reach a definitive
resolution on whether smartphones qualify as autodialers.
As we have explained, however, a straightforward reading of
the Commission’s ruling invites the conclusion that all
smartphones are autodialers: the ruling explained that a
number of parties specifically raised the issue; and it
responded, not by disputing the parties’ concerns that
smartphones would be covered by the statutory definition
under the agency’s approach, but instead by accepting that
conclusion and then questioning whether uninvited calls in
fact would be made and lawsuits in fact would be brought.
                              21
     It is highly difficult to read the Commission’s ruling to
leave uncertain whether the statutory definition applies to
smartphones. And any uncertainty on that score would have
left affected parties without concrete guidance even though
several of them specifically raised the issue with the agency,
and even though the issue carries significant implications—
including the possibility of committing federal law violations
and incurring substantial liability in damages—for
smartphone owners.

     At any rate, even assuming the Commission’s ruling
could be conceived to leave room for concluding that
smartphones do not qualify as autodialers, that result itself
would be unreasonable and impermissible.                 The
Commission’s order, in that event, would not constitute
reasoned decisionmaking and thus would not satisfy APA
arbitrary-and-capricious review. See United States Postal
Serv. v. Postal Regulatory Comm’n, 785 F.3d 740, 754 (D.C.
Cir. 2015).

     Administrative action is “arbitrary and capricious [if] it
fails to articulate a comprehensible standard” for assessing the
applicability of a statutory category. Id. at 753. If a
“purported standard is indiscriminate and offers no
meaningful guidance” to affected parties, it will fail “the
requirement of reasoned decisionmaking.” Id. at 754. That
will be the case if an agency cannot satisfactorily explain why
a challenged standard embraces one potential application but
leaves out another, seemingly similar one. See id. at 754-55.

     That would be precisely the situation here if, as the
Commission now contends in its briefing before us, its order
in fact left open the possibility that smartphones fail to meet
the statutory definition of an ATDS. In the same briefing, the
Commission, as noted, simultaneously maintained that the
                                22
Firefox browser has the “capacity” to play Flash videos
because the Flash plug-in can be downloaded. Precisely the
same logic seemingly should compel concluding that
smartphones have the “capacity” to function as autodialers
because apps carrying the requisite features can be
downloaded.       If the Commission believes smartphones
nonetheless do not meet the definition of an autodialer, there
is no explanation of “this differential treatment of seemingly
like cases.” Id. at 755 (internal quotation marks omitted).

    The Commission did say in its order that “there must be
more than a theoretical potential that the equipment could be
modified to satisfy the ‘autodialer’ definition.”        2015
Declaratory Ruling, 30 FCC Rcd. at 7975 ¶ 18. But that
ostensible limitation affords no ground for distinguishing
between a smartphone and the Firefox browser. In light of the
ease of downloading an app to a smartphone, there is no
evident basis for concluding that the Firefox browser has
more than a mere “theoretical potential” to play Flash videos
by downloading a plug-in, but a smartphone nonetheless has
only a “theoretical potential” to function as an autodialer by
downloading an app.

     The point is fortified by the sole example of a mere
“theoretical potential” set forth by the Commission in its
order. That example involves a traditional rotary-dial phone
(which by now is approaching obsolescence):                      the
Commission observed that “it might be theoretically possible
to modify a rotary-dial telephone to such an extreme that it
would satisfy the definition of ‘autodialer,’ but such a
possibility is too attenuated . . . to find that a rotary-dial phone
has the requisite ‘capacity’ and therefore is an autodialer.” Id.
A rotary phone has no relevant similarity to a smartphone. To
the contrary, whereas a smartphone and the Firefox browser
substantially resemble one another in their amenability to an
                              23
upgrade via the addition of software, they substantially differ
in that regard from a rotary-dial phone, which has no such
capability.

     In the end, then, the Commission’s order cannot
reasonably be understood to support the conclusion that
smartphones fall outside the TCPA’s autodialer definition:
any such reading would compel concluding that the agency’s
ruling fails arbitrary-and-capricious review.      The more
straightforward understanding of the Commission’s ruling is
that all smartphones qualify as autodialers because they have
the inherent “capacity” to gain ATDS functionality by
downloading an app. That interpretation of the statute, for all
the reasons explained, is an unreasonably, and impermissibly,
expansive one.

                               2.

      Recall that the statutory definition of an ATDS raises two
sets of questions: (i) when does a device have the “capacity”
to perform the functions of an autodialer enumerated by the
statute?; and (ii) what precisely is the content of those
functions?      The impermissibility of the Commission’s
interpretation of the term “capacity” in the autodialer
definition is compounded by inadequacies in the agency’s
explanation of the requisite features. Having addressed the
first issue, we now turn to the second one.

     a. As a threshold matter, the Commission maintains that
the court lacks jurisdiction to entertain petitioners’ challenge
concerning the functions a device must be able to perform.
The agency reasons that the issue was resolved in prior
agency orders—specifically, declaratory rulings in 2003 and
2008 concluding that the statutory definition of an ATDS
includes “predictive dialers,” dialing equipment that can make
                              24
use of algorithms to “assist[] telemarketers in predicting when
a sales agent will be available to take calls.” 2015
Declaratory Ruling, 30 FCC Rcd. at 7972 ¶ 10 n.39; see also
In re Rules and Regulations Implementing the Telephone
Consumer Protection Act of 1991 (2008 Declaratory Ruling),
23 FCC Rcd. 559 (2008); 2003 Order, 18 FCC Rcd. 14,014.
According to the Commission, because there was no timely
appeal from those previous orders, it is too late now to raise a
challenge by seeking review of a more recent declaratory
ruling that essentially ratifies the previous ones. We disagree.

     While the Commission’s latest ruling purports to reaffirm
the prior orders, that does not shield the agency’s pertinent
pronouncements from review. The agency’s prior rulings left
significant uncertainty about the precise functions an
autodialer must have the capacity to perform. Petitioners
covered their bases by filing petitions for both a declaratory
ruling and a rulemaking concerning that issue and related
ones. See, e.g., Prof’l Ass’n for Customer Engagement, Inc.
Pet. 3-4; ACA Int’l Pet. 6; GroupMe, Inc. Pet. 3; Glide Talk,
Ltd. Pet. 13.      In response, the Commission issued a
declaratory ruling that purported to “provid[e] clarification on
the definition of ‘autodialer,’” and denied the petitions for
rulemaking on the issue. 2015 Declaratory Ruling, 30 FCC
Rcd. at 8039 ¶ 165 & n.552. The ruling is thus reviewable on
both grounds. See 5 U.S.C. § 554(e); Biggerstaff v. FCC, 511
F.3d 178, 184-85 (D.C. Cir. 2007).

    b. The statutory definition says that a device constitutes
an ATDS if it has the capacity to perform both of two
enumerated functions:     “to store or produce telephone
numbers to be called, using a random or sequential number
generator”; and “to dial such numbers.”           47 U.S.C.
§ 227(a)(1)(A)-(B). The role of the phrase, “using a random
or sequential number generator,” has generated substantial
                             25
questions over the years. The Commission has sought to
address those questions in previous orders and did so again in
the 2015 Declaratory Ruling we consider here.

     The Commission’s most recent effort falls short of
reasoned decisionmaking in “offer[ing] no meaningful
guidance” to affected parties in material respects on whether
their equipment is subject to the statute’s autodialer
restrictions. Postal Regulatory Comm’n, 785 F.3d at 754. A
basic question raised by the statutory definition is whether a
device must itself have the ability to generate random or
sequential telephone numbers to be dialed. Or is it enough if
the device can call from a database of telephone numbers
generated elsewhere? The Commission’s ruling appears to be
of two minds on the issue.

     In certain respects, the order conveys that equipment
needs to have the ability to generate random or sequential
numbers that it can then dial. The order twice states that, to
“meet[] the TCPA’s definition of ‘autodialer,’” the equipment
in question must have the capacity to “dial random or
sequential numbers.” 2015 Declaratory Ruling, 30 FCC Rcd.
at 7972 ¶ 10; see also id. at 7974 ¶ 15. And it is clear from
context that the order treats the ability to “dial random or
sequential numbers” as the ability to generate and then dial
“random or sequential numbers.”

     To see why, it is helpful to understand that the ruling
distinguishes between use of equipment to “dial random or
sequential numbers” and use of equipment to “call[] a set list
of consumers.” Id. at 7972 ¶ 10. Anytime phone numbers are
dialed from a set list, the database of numbers must be called
in some order—either in a random or some other sequence.
As a result, the ruling’s reference to “dialing random or
sequential numbers” cannot simply mean dialing from a set
                              26
list of numbers in random or other sequential order: if that
were so, there would be no difference between “dialing
random or sequential numbers” and “dialing a set list of
numbers,” even though the ruling draws a divide between the
two. See id. at 7973 ¶¶ 13, 14. It follows that the ruling’s
reference to “dialing random or sequential numbers” means
generating those numbers and then dialing them.

     The Commission’s prior declaratory rulings reinforce that
understanding. In its 2003 ruling addressing predictive
dialers, the Commission observed that, “[i]n the past,
telemarketers may have used dialing equipment to create and
dial 10-digit telephone numbers arbitrarily.” 2003 Order, 18
FCC Rcd. at 14,092 ¶ 132 (emphasis added). But the industry
had “progressed to the point where” it had become “far more
cost effective” instead to “us[e] lists of numbers.” Id. Again,
the Commission suggested it saw a difference between calling
from a list of numbers, on one hand, and “creating and
dialing” a random or arbitrary list of numbers, on the other
hand. Or as the Commission has elsewhere said, numbers that
are “randomly or sequentially generated” differ from numbers
that “come from a calling list.” In re Implementation of the
Middle Class Tax Relief and Job Creation Act of 2012, 27
FCC Rcd. 13,615, 13,629 ¶ 29 (2012) (quoted in 2015
Declaratory Ruling, 30 FCC Rcd. at 8077 (Comm’r Pai,
dissenting)).

     While the 2015 ruling indicates in certain places that a
device must be able to generate and dial random or sequential
numbers to meet the TCPA’s definition of an autodialer, it
also suggests a competing view: that equipment can meet the
statutory definition even if it lacks that capacity. The
Commission reaffirmed its 2003 ruling insofar as that order
had found predictive dialers to qualify as ATDSs. 2015
Declaratory Ruling, 30 FCC Rcd. at 7972-73 ¶¶ 12-14. And
                              27
in the 2003 order, the Commission had made clear that, while
some predictive dialers cannot be programmed to generate
random or sequential phone numbers, they still satisfy the
statutory definition of an ATDS. 2003 Order, 18 FCC Rcd. at
14,091 ¶ 131 n.432; id. at 14,093 ¶ 133. By reaffirming that
conclusion in its 2015 ruling, the Commission supported the
notion that a device can be considered an autodialer even if it
has no capacity itself to generate random or sequential
numbers (and instead can only dial from an externally
supplied set of numbers). The 2015 ruling correspondingly
expresses that “predictive dialers” can differ from other
“dialers that utilize random or sequential numbers instead of a
list of numbers.” 2015 Declaratory Ruling, 30 FCC Rcd. at
7973 ¶ 14.

     So which is it: does a device qualify as an ATDS only if
it can generate random or sequential numbers to be dialed, or
can it so qualify even if it lacks that capacity? The 2015
ruling, while speaking to the question in several ways, gives
no clear answer (and in fact seems to give both answers). It
might be permissible for the Commission to adopt either
interpretation. But the Commission cannot, consistent with
reasoned decisionmaking, espouse both competing
interpretations in the same order.

     The choice between the interpretations is not without
practical significance. Petitioners and various amici describe
calling equipment that they wish to use to call set lists of
cellular numbers without any generation of random or
sequential numbers. See ACA Int’l Reply Br. 21; Am.
Bankers Ass’n Amicus Br. 29-30. And at least some
predictive dialers, as explained, have no capacity to generate
random or sequential numbers.
                               28
    The uncertainty in the 2015 ruling, moreover, does not
stop with the question of whether a device must be able to
generate random or sequential numbers to meet the statutory
definition. The ruling is also unclear about whether certain
other referenced capabilities are necessary for a dialer to
qualify as an ATDS.

     For instance, the ruling states that the “basic function” of
an autodialer is the ability to “dial numbers without human
intervention.” 2015 Declaratory Ruling, 30 FCC Rcd. at 7973
¶ 14; id. at 7975 ¶ 17. Prior orders had said the same. 2003
Order, 18 FCC Rcd. at 14,092 ¶ 132; 2008 Declaratory
Ruling, 23 FCC Rcd. at 566 ¶ 13. That makes sense given
that “auto” in autodialer—or, equivalently, “automatic” in
“automatic telephone dialing system,” 47 U.S.C.
§ 227(a)(1)—would seem to envision non-manual dialing of
telephone numbers.

     But the Commission nevertheless declined a request to
“clarify[] that a dialer is not an autodialer unless it has the
capacity to dial numbers without human intervention.” 2015
Declaratory Ruling, 30 FCC Rcd. at 7976 ¶ 20. According to
the Commission, then, the “basic function” of an autodialer is
to dial numbers without human intervention, but a device
might still qualify as an autodialer even if it cannot dial
numbers without human intervention. Those side-by-side
propositions are difficult to square.

     The Commission further said that another “basic
function[]” of an ATDS is to “dial thousands of numbers in a
short period of time.” Id. at 7975 ¶ 17. But the ruling imparts
no additional guidance concerning whether that is a necessary
condition, a sufficient condition, a relevant condition even if
neither necessary nor sufficient, or something else. Nor does
it indicate what would qualify as a “short period of time.”
                               29
Again, affected parties are left in a significant fog of
uncertainty about how to determine if a device is an ATDS so
as to bring into play the restrictions on unconsented calls.

     In short, the Commission’s ruling, in describing the
functions a device must perform to qualify as an autodialer,
fails to satisfy the requirement of reasoned decisionmaking.
The order’s lack of clarity about which functions qualify a
device as an autodialer compounds the unreasonableness of
the Commission’s expansive understanding of when a device
has the “capacity” to perform the necessary functions. We
must therefore set aside the Commission’s treatment of those
matters.

                               3.

     We briefly note an additional statutory provision
affecting the scope of the TCPA’s restrictions on autodialer
calls to cell numbers—a provision we ultimately have no
occasion to examine because of the way the case has been
presented to us. Two TCPA provisions work together to
establish the reach of the general prohibition against making
autodialer calls without prior consent. The first provision, as
we have seen, defines the equipment—viz., “automatic
telephone dialing system”—subject to the statutory
prohibition. 47 U.S.C. § 227(a)(1). The second provision
then incorporates that definition in setting out the scope of the
prohibition: “It shall be unlawful for any person . . . to make
any call (other than a call made for emergency purposes or
made with the prior express consent of the called party) using
any automatic telephone dialing system . . . to any telephone
number assigned to a . . . cellular telephone service[.]” Id.
§ 227(b)(1)(A)(iii) (emphases added).
                              30
     Petitioners have confined their challenge to the
Commission’s understanding of the first of those provisions,
the statutory definition of an autodialer, and our analysis has
been focused on that issue. Petitioners have raised no
challenge to the Commission’s understanding of the second
provision—i.e., to the agency’s interpretation of what it
means to “make any call using any” ATDS. In particular, in
the case of a device having the “capacity” both to perform the
autodialer functions set out in the statutory definition and to
perform as a traditional phone, does the bar against “making
any call using” an ATDS apply only to calls made using the
equipment’s ATDS functionality? Or does the bar apply to all
calls made with a device having that “capacity,” even ones
made without any use of the equipment’s autodialer
capabilities? Or does the bar apply to calls made using
certain autodialer functions, even if not all of them?

     The Commission’s ruling endorsed a broad
understanding under which the statute prohibits any calls
made from a device with the capacity to function as an
autodialer, regardless of whether autodialer features are used
to make a call. 2015 Declaratory Ruling, 30 FCC Rcd. at
7975 ¶ 19 n.70. A dissenting commissioner, by contrast, read
the pertinent statutory phrase, “make any call,” to mean “that
the equipment must, in fact, be used as an autodialer to make
the calls” before a TCPA violation can be found. Id. at 8088
(Comm’r O’Rielly, dissenting in part and approving in part).

     The dissenting commissioner’s interpretation would
substantially diminish the practical significance of the
Commission’s expansive understanding of “capacity” in the
autodialer definition. Even if the definition encompasses any
device capable of gaining autodialer functionality through the
downloading of software, the mere possibility of adding those
features would not matter unless they were downloaded and
                             31
used to make calls. Under the dissent’s understanding of the
phrase, “make any call,” then, everyday calls made with a
smartphone would not infringe the statute: the fact that a
smartphone could be configured to function as an autodialer
would not matter unless the relevant software in fact were
loaded onto the phone and were used to initiate calls or send
messages.

     Petitioners, however, raise no challenge to the
Commission’s understanding of the statutory words, “make
any call using” an ATDS, and the parties therefore have not
presented arguments on the issue in their briefing before us.
Our consistent practice in such a situation is to decline to
address (much less resolve) the issue. See, e.g., U.S. Telecom
Ass’n v. FCC, 825 F.3d 674, 697 (D.C. Cir. 2016). We “sit to
resolve only legal questions presented and argued by the
parties.” Id. (internal quotation marks omitted). We
nonetheless note the issue in light of its potential interplay
with the distinct challenges petitioners do raise. The agency
could choose to revisit the issue in a future rulemaking or
declaratory order, and a party might then raise the issue on
judicial review.

                             B.

     We now turn to the Commission’s treatment of
circumstances in which a consenting party’s cell number has
been reassigned to another person. While there is no
consensus about the exact numbers of reassignments, there is
no dispute that millions of wireless numbers are reassigned
each year. In the event of a reassignment, the caller might
initiate a phone call (or send a text message) based on a
mistaken belief that the owner of the receiving number has
given consent, when in fact the number has been reassigned to
someone else from whom consent has not been obtained.
                             32
     Does a call or message in that situation violate the
statutory bar against making autodialer calls without prior
consent? The Commission’s answer is yes, apart from a one-
call, post-reassignment safe harbor. We set aside the
Commission’s interpretation on the ground that the one-call
safe harbor is arbitrary and capricious.

                              1.

     The pertinent statutory language generally renders it
unlawful “to make any call (other than a call made for
emergency purposes or made with the prior express consent
of the called party) using any automatic telephone dialing
equipment or prerecorded voice.” 47 U.S.C. § 227(b)(1)(A)
(emphasis added). The Commission, in its ruling, initially
addressed who is properly considered the “called party” when
a consenting party’s number is reassigned to another person:
does “called party” refer to the person the caller expected to
reach (whose consent had previously been obtained), or does
it refer to the person actually reached, the wireless number’s
present-day subscriber after reassignment (whose consent has
not been obtained)?

     The Commission adopted the latter interpretation. 30
FCC Rcd. at 7999-8001 ¶¶ 72-73. The result is that the
reassignment of a wireless number extinguishes any consent
given by the number’s previous holder and exposes the caller
to liability for reaching a party who has not given consent.
An alternative approach, the Commission reasoned, would
“effectively require consumers to opt out of such calls when
the TCPA clearly requires the opposite—that consumers opt
in before they can be contacted.” Id. at 8004 ¶ 80.

    The agency also refused to “place any affirmative
obligation” on new subscribers to inform callers that a
                               33
wireless number now belongs to someone else. Id. at 8011
¶ 95. The ruling thus expressly contemplates that a new
subscriber could “purposefully and unreasonably” refrain
from informing a good-faith caller about a number’s
reassignment “in order to accrue statutory penalties.” Id.
(formatting modified). In that regard, the Commission
described a reported case in which the new, post-reassignment
subscriber waited to initiate a lawsuit until after having
received almost 900 text alerts that were intended for the
previous subscriber. Id. at 8011 ¶ 94 & n.324.

     The Commission acknowledged that even the most
careful caller, after employing all reasonably available tools
to learn about reassignments, “may nevertheless not learn of
reassignment before placing a call to a new subscriber.” Id. at
8009 ¶ 88. The Commission observed that it nonetheless
“could have interpreted the TCPA to impose a traditional
strict liability standard on the caller: i.e., a ‘zero call’
approach under which no allowance would have been given
for the robocaller to learn of the reassignment.” Id. at 8009
¶ 90 n.312. But the Commission declined to interpret the
statute “to require a result that severe.” Id. Rather, the
Commission read the statute to “anticipate[] the caller’s
ability to rely on prior express consent,” which the
Commission interpreted “to mean reasonable reliance.” Id.
(internal quotation marks omitted).

      The Commission effectuated its “reasonable reliance”
approach by enabling a caller who lacks knowledge of a
reassignment “to avoid liability for the first call to a wireless
number following reassignment.” Id. at 8009 ¶ 89. For that
first call, the caller can continue to rely on the consent given
by the “previous subscriber.” Id. at 8003 ¶ 78. The
Commission did “not presume that a single call to a
reassigned number will always be sufficient for callers to gain
                              34
actual knowledge of the reassignment.” Id. at 8009 ¶ 90
n.312. But it believed that “[o]ne call represents an
appropriate balance between a caller’s opportunity to learn of
the reassignment and the privacy interests of the new
subscriber.” Id. at 8009 ¶ 90.

                              2.

      In challenging the Commission’s resolution, petitioners
first contend that the statutory reference to the consent of the
“called party” refers to the expected recipient of a call or
message, not the actual recipient. When a wireless number is
reassigned without the caller’s awareness, petitioners’
interpretation would mean that a caller would avoid liability
for a post-reassignment call because the “called party”—the
former owner of the number—had given consent. In
petitioners’ view, the Commission’s contrary interpretation of
“called party” to refer to the new (post-reassignment)
subscriber is foreclosed by the statute. We disagree.

     Another court of appeals has examined the meaning of
the term “called party” in the same statutory provision, 47
U.S.C. § 227(b)(1)(A), and in the same situation of a
reassigned wireless number formerly belonging to a
consenting party. Soppet v. Enhanced Recovery Co., 679 F.3d
637 (7th Cir. 2012). The Seventh Circuit explained that the
phrase “called party” appears throughout the broader statutory
section, 47 U.S.C. § 227, a total of seven times. 679 F.3d at
640. Four of those instances “unmistakably denote the
current subscriber,” not the previous, pre-reassignment
subscriber. Id. Of the three remaining instances, “one
denotes whoever answers the call (usually the [current]
subscriber),” and the other two are unclear. Id. By contrast,
the court observed, the “phrase ‘intended recipient’ does not
appear anywhere in § 227, so what justification could there be
                                35
for equating ‘called party’ with ‘intended recipient of the
call’?” Id. For those and other reasons, the court concluded
“that ‘called party’ in § 227(b)(1) means the person
subscribing to the called number at the time the call is made,”
not the previous subscriber who had given consent. Id. at
643; see also Osorio v. State Farm Bank, F.S.B., 746 F.3d
1242, 1250-52 (11th Cir. 2014).

     We find the Seventh Circuit’s analysis persuasive insofar as
it supports concluding that the Commission was not
compelled to interpret “called party” in § 227(b)(1)(A) to
mean the “intended recipient” rather than the current
subscriber. The Commission thus could permissibly interpret
“called party” in that provision to refer to the current
subscriber.

                                3.

     Petitioners next argue that the Commission’s one-call
safe harbor is arbitrary. On this score, we agree with
petitioners.

     When a caller is unaware that a consenting party’s
wireless number has been reassigned, the Commission chose
to allow the caller to make one (and only one) post-
reassignment call without incurring liability. For that one
call, the Commission understood the statutory term “prior
express consent” to refer to the consent given by the previous
subscriber. 30 FCC Rcd. at 8001 ¶ 73 & n.265; id. at 8003
¶ 78.

     The Commission allowed for that one liability-free call,
rather than impose “a traditional strict liability standard,”
because it interpreted a caller’s ability under the statute to rely
on a recipient’s “prior express consent” to “mean reasonable
                              36
reliance.” Id. at 8009 ¶ 90 n.312. And when a caller has no
knowledge      of    a   reassignment,     the  Commission
understandably viewed the caller’s continued reliance on the
prior subscriber’s consent to be “reasonable.”

     Elsewhere in the Declaratory Ruling, the Commission
echoed the same “reasonable reliance” understanding of the
statute’s approval of calls based on “prior express consent.”
The ruling accepts that a caller can rely on consent given by a
wireless number’s “customary user” (“such as a close relative
on a subscriber’s family calling plan”), rather than by the
subscriber herself. Id. at 8001 ¶ 75. That is because the
“caller in this situation cannot reasonably be expected to
divine that the consenting person is not the subscriber.” Id. at
8001-02 ¶ 75. The Commission reiterated in that regard that,
in “construing the term ‘prior express consent’ in section
227(b)(1)(A), we consider the caller’s reasonableness in
relying on consent.” Id. at 8001 ¶ 75.

     The Commission thus consistently adopted a “reasonable
reliance” approach when interpreting the TCPA’s approval of
calls based on “prior express consent,” including as the
justification for allowing a one-call safe harbor when a
consenting party’s number is reassigned. The Commission,
though, gave no explanation of why reasonable-reliance
considerations would support limiting the safe harbor to just
one call or message. That is, why does a caller’s reasonable
reliance on a previous subscriber’s consent necessarily cease
to be reasonable once there has been a single, post-
reassignment call? The first call or text message, after all,
might give the caller no indication whatsoever of a possible
reassignment (if, for instance, there is no response to a text
message, as would often be the case with or without a
reassignment).
                               37
      The Commission outlined a number of measures callers
could undertake “that, over time, may permit them to learn of
reassigned numbers.” Id. at 8007 ¶ 86. But the Commission
acknowledged that callers “may nevertheless not learn of
reassignment before placing a call to a new subscriber,” and
that the first post-reassignment call likewise might give no
reason to suspect a reassignment. Id. at 8009 ¶¶ 88, 90 n.312.
In that event, a caller’s reasonable reliance on the previous
subscriber’s consent would be just as reasonable for a second
call.

     To be sure, the Commission stated that it found “no basis
in the statute or the record before [it] to conclude that callers
can reasonably rely on prior express consent beyond one call
to reassigned numbers.” Id. at 8009-10 ¶ 90 n.312. But the
Commission did not elaborate on—or otherwise support—its
conclusory observation to that effect. And the statement is
hard to square with the Commission’s concession that the first
call may give no notice of a reassignment, or with the
Commission’s disavowal of any expectation that a caller
should “divine from the called consumer’s mere silence the
current status of a telephone number.” Id. (brackets omitted).
In that light, no cognizable conception of “reasonable
reliance” supports the Commission’s blanket, one-call-only
allowance.

     At times, the Commission indicated that its one-call safe
harbor intends to give callers additional “opportunity” to find
out about a possible reassignment. E.g., id. at 8009 ¶ 89; id.
at 8010 ¶ 91. There is no indication, though, that the interest
in giving callers such an opportunity is independent of the
interest in giving effect to a caller’s reasonable reliance.
After all, a caller also has an opportunity to learn of a
reassignment before the first call. The reason to allow even
one, liability-free, post-reassignment call—the reason the
                              38
Commission cared about affording an opportunity to learn
about reassignment at all—is in order to give effect to a
caller’s reasonable reliance on the previous subscriber’s
consent.

     Indeed, the Commission’s one-call safe harbor applies
“over an unlimited period of time.” Id. at 8000 ¶ 72 n.257.
If the goal were simply to provide an expanded opportunity to
learn about a reassignment, the Commission presumably
would have allowed for a given period of time. It declined to
do so, id. at 8009 ¶ 89, opting instead to permit a single call
regardless of whether it occurs within minutes or months of a
reassignment.

     For substantially the same reasons, the Commission’s
one-call-only approach cannot be salvaged by its suggestion
that callers rather than new subscribers should bear the risk
when calls are made (or messages are sent) to a reassigned
number. Id. at 8009-10 ¶ 90 n.312. That consideration would
equally support a zero-call, strict-liability rule. But the
Commission specifically declined to adopt “a result that
severe.” Id. Having instead embraced an interpretation of the
statutory phrase “prior express consent” grounded in
conceptions of reasonable reliance, the Commission needed to
give some reasoned (and reasonable) explanation of why its
safe harbor stopped at the seemingly arbitrary point of a
single call or message. The Commission did not do so.

     The Seventh Circuit’s decision in Soppet, discussed
earlier, is not to the contrary. There, the court assumed that
“any consent previously given . . . lapses when [a] [c]ell
[n]umber is reassigned.” 679 F.3d at 641. The court, though,
did not have before it an agency interpretation under which
the previous subscriber’s consent does not lapse with
reassignment: the premise of the Commission’s one-call safe
                              39
harbor is that a caller can continue to rely on the previous
subscriber’s consent. The question we face is, why should
that necessarily stop with a single call? Soppet does not speak
to that question, and so does not cast doubt on our conclusion
that the Commission failed to give it a satisfactory answer.

     Finally, the Commission’s failure in that regard requires
setting aside not only its allowance of a one-call safe harbor,
but also its treatment of reassigned numbers more generally.
When we invalidate a specific aspect of an agency’s action,
we leave related components of the agency’s action standing
only if “we can say without any ‘substantial doubt’ that the
agency would have adopted the severed portion on its own.”
Am. Petroleum Inst. v. EPA, 862 F.3d 50, 71 (D.C. Cir. 2017)
(per curiam) (internal quotation marks omitted).

     Here, we have no such assurance. If we were to excise
the Commission’s one-call safe harbor alone, that would leave
in place the Commission’s interpretation that “called party”
refers to the new subscriber. And that in turn would mean
that a caller is strictly liable for all calls made to the
reassigned number, even if she has no knowledge of the
reassignment.

     We cannot be certain that the agency would have adopted
that rule in the first instance. Significantly, the Commission
said that it “could have interpreted the TCPA to impose a
traditional strict liability standard,” i.e., “a ‘zero call’
approach.” 30 FCC Rcd. at 8009 ¶ 90 n.312. But the agency
declined to “require a result that severe,” opting instead for a
one-call safe harbor. Id. We cannot say without any
substantial doubt that the agency would have embraced the
“severe” implications of a pure, strict-liability regime even in
the absence of any safe harbor. As a result, we must set aside
                               40
the Commission’s treatment of reassigned numbers as a
whole.

     Notably, the Commission is already on its way to
designing a regime to avoid the problems of the 2015 ruling’s
one-call safe harbor. The Commission recently sought
comment on potential methods for “requir[ing] service
providers to report information about number reassignments
for the purposes of reducing unwanted robocalls.” In re
Advanced Methods to Target and Eliminate Unlawful
Robocalls, Second Notice of Inquiry, 32 FCC Rcd. 6007,
6010 ¶ 9 (2017). Most of its proposals envision creating a
comprehensive repository of information about reassigned
wireless numbers. See id. at 6012-13 ¶¶ 15-19. The
Commission is also considering whether to provide a safe
harbor for callers that inadvertently reach reassigned numbers
after consulting the most recently updated information. See
id. at 6012 ¶ 14. Those proposals would naturally bear on the
reasonableness of calling numbers that have in fact been
reassigned, and have greater potential to give full effect to the
Commission’s principle of reasonable reliance.

                               C.

     It is undisputed that consumers who have consented to
receiving calls otherwise forbidden by the TCPA are entitled
to revoke their consent. See 2015 Declaratory Ruling, 30
FCC Rcd. at 7996 ¶ 62. The statute, however, does not
elaborate on the processes by which consumers may validly
do so. The Commission sought to resolve the matter in its
Declaratory Ruling.

     The Commission had been petitioned to clarify that
callers can unilaterally prescribe the exclusive means for
consumers to revoke their consent. It explicitly denied that
                              41
request. Allowing “callers to designate the exclusive means
of revocation,” the Commission believed, could “materially
impair” the “right of revocation.” Id. at 7997 ¶ 66.

     The Commission instead concluded that “a called party
may revoke consent at any time and through any reasonable
means”—orally or in writing—“that clearly expresses a desire
not to receive further messages.” Id. at 7989-90 ¶ 47; id. at
7996 ¶ 63. In assessing whether a revocation request meets
the “reasonable means” standard, the Commission said it
would consider “the totality of the facts and circumstances.”
Id. at 7996 ¶ 64 n.233. One relevant factor is “whether the
caller could have implemented mechanisms to effectuate a
requested revocation without incurring undue burdens.” Id.
Another consideration is “whether the consumer had a
reasonable expectation that he or she could effectively
communicate his or her request . . . in that circumstance.” Id.

    Petitioners challenge the Commission’s treatment of
revocations on various grounds, none of which we find
persuasive.    Petitioners’ chief objection is that the
Commission’s approach is arbitrary and capricious in
eschewing the establishment of standardized revocation
procedures in favor of an unduly uncertain, any-reasonable-
means standard. Without the certainty of standardized
procedures, petitioners fear, they will be able to ward off
TCPA liability only by “tak[ing] exorbitant precautions.”
ACA Int’l Br. 57.

    We think petitioners’ concerns are overstated. The
Commission’s ruling absolves callers of any responsibility to
adopt systems that would entail “undue burdens” or would be
“overly burdensome to implement.” 30 FCC Rcd. at 7996
¶ 64 & n.233. In light of that assurance, callers would have
no need to train every retail employee on the finer points of
                              42
revocation. And callers will have every incentive to avoid
TCPA liability by making available clearly-defined and easy-
to-use opt-out methods. If recipients are afforded such
options, any effort to sidestep the available methods in favor
of idiosyncratic or imaginative revocation requests might well
be seen as unreasonable. The selection of an unconventional
method of seeking revocation might also betray the absence
of any “reasonable expectation” by the consumer that she
could “effectively communicate” a revocation request in the
chosen fashion. Id.

     Petitioners observe that the Commission’s ruling itself
dictates particular opt-out mechanisms for certain types of
time-sensitive banking- and healthcare-related calls that the
Commission exempted from the TCPA’s consumer consent
requirements. Id. at 8028 ¶ 138; id. at 8032 ¶ 147. If the
Commission prescribed specific opt-out methods for those
types of calls, petitioners ask, then why not similarly set out
standardized means of revocation for all calls?

     The Commission was not required to treat the two
situations in a parallel manner. For the banking- and
healthcare-related calls, the Commission found that the
communications were sufficiently important to warrant an
exemption from the otherwise-applicable obligation to obtain
prior consent. Id. at 8023 ¶ 125. As a result, the default rule
for those calls is that they should be allowed (without regard
to consent), such that the availability of an opt-out can be
conditioned on adhering to specific procedures. By contrast,
the default rule for non-exempted calls is that they are
disallowed (absent consent), such that the availability of an
opt-out naturally could be broader. In that context, the
Commission could reasonably elect to enable consumers to
revoke their consent without having to adhere to specific
procedures.
                               43
     Finally, petitioners object to the Declaratory Ruling
insofar as it might preclude callers and consumers from
contractually agreeing to revocation mechanisms.           The
Commission correctly concedes, however, that the ruling “did
not address whether contracting parties can select a particular
revocation procedure by mutual agreement.” FCC Br. 64
n.16. The ruling precludes unilateral imposition of revocation
rules by callers; it does not address revocation rules mutually
adopted by contracting parties. Nothing in the Commission’s
order thus should be understood to speak to parties’ ability to
agree upon revocation procedures.

                               D.

     The last set of challenges before us, brought by petitioner
Rite Aid, concerns the scope of the Commission’s exemption
of certain healthcare-related calls from the TCPA’s prior-
consent requirement for calls to wireless numbers. The
Commission is statutorily authorized to exempt from that
requirement “calls to a telephone number assigned to a
cellular telephone service that are not charged to the called
party, subject to such conditions as the Commission may
prescribe as necessary in the interest of the privacy rights this
section is intended to protect.” 47 U.S.C. § 227(b)(2)(C).

     The Commission was petitioned to exempt from the
consent requirement “certain non-telemarketing, healthcare
calls” alleged to “provide vital, time-sensitive information
patients welcome, expect, and often rely on to make informed
decisions.” 2015 Declaratory Ruling, 30 FCC Rcd. at 8030
¶ 143. The agency acknowledged the “exigency and public
interest” in various types of healthcare-related calls, including
ones “regarding post-discharge follow-up intended to prevent
readmission, or prescription notifications.” Id. at 8031 ¶ 146.
But it was “concerned that these policy arguments are not
                              44
true” for other types of healthcare calls. Id. Specifically, the
Commission “fail[ed] to see the same exigency and public
interest in calls regarding account communications and
payment notifications.” Id.

     Consequently, the Commission granted the requested
exemption but “restrict[ed] it to calls for which there is
exigency and that have a healthcare treatment purpose,
specifically:   appointment and exam confirmations and
reminders, wellness checkups, hospital pre-registration
instructions, pre-operative instructions, lab results, post-
discharge follow-up intended to prevent readmission,
prescription notifications, and home healthcare instructions.”
Id. The exemption would not cover calls “that include
telemarketing, solicitation, or advertising content, or which
include accounting, billing, debt-collection, or other financial
content.” Id.

    Petitioner Rite Aid challenges the Commission’s
exemption for select healthcare-related calls on the grounds
that it conflicts with another federal statute (the Health
Insurance Portability and Accountability Act, or HIPAA) and
is arbitrary and capricious.        Rite Aid’s arguments
misunderstand the relevant statutory terrain, and we reject
them.

                               1.

     At the outset, we must satisfy ourselves that we have
jurisdiction to entertain Rite Aid’s challenge. Rite Aid has
been styled a petitioner here, but it did not formally petition
the Commission in the proceedings before the agency. The
petition granted by the Commission in part was filed by the
American Association of Healthcare Administrative
Management (the Association). Rite Aid expressed “support”
                              45
for the Association’s petition for a declaratory ruling and
exemption, and it also asked the Commission to “address
certain additional issues.” Comments of Rite Aid, Joint
App’x 850. But it participated only by commenting on the
Association’s petition rather than filing one of its own. As a
result, with respect to relief that only Rite Aid sought, the
Commission “decline[d] to fully address th[at] request for
clarification . . . raised in a comment to a pending Petition.”
2015 Declaratory Ruling, 30 FCC Rcd. at 8028-29 ¶ 141
n.471. The Association did not appeal the FCC’s partial
denial of its requested exemption. Instead, Rite Aid has
petitioned the court to review that denial.

     Direct review of final FCC orders is governed by the
Hobbs Act, under which “[a]ny party aggrieved by [a] final
order” of the Commission may petition for review of that
order. 28 U.S.C. § 2344. We have consistently held that the
phrase “party aggrieved” requires that petitioners have been
parties to the underlying agency proceedings, not simply
parties to the present suit who are aggrieved in a
constitutional (Article III) sense. See Simmons v. ICC, 716
F.2d 40, 42 (D.C. Cir. 1983). The question here is whether
commenting on a petition in agency proceedings that resulted
in a declaratory ruling suffices to confer “party aggrieved”
status on a litigant whose position the agency rejected.

     We find it does. For agency proceedings that do not
require intervention as a prerequisite to participation, our
decisions have recognized that “party aggrieved” means a
party who has “made a full presentation of views to the
agency.” Water Transp. Ass’n v. ICC, 819 F.2d 1189, 1193
(D.C. Cir. 1987). Rite Aid fulfilled that requirement. Just as
“submitting comments” confers “party aggrieved” status in
the context of a rulemaking (assuming an adverse outcome),
Prof’l Reactor Operator Soc’y v. U.S. Nuclear Regulatory
                             46
Comm’n, 939 F.2d 1047, 1049 n.1 (D.C. Cir. 1991), one who
comments on another’s petition for a rulemaking or
declaratory ruling has “present[ed] its view to the agency [so
as] to qualify as a ‘party,’” S. Pac. Transp. Co. v. ICC, 69
F.3d 583, 588 (D.C. Cir. 1995)—at least insofar as the issues
appealed were also taken up by the petitioner below (as they
were here). Rite Aid afforded the Commission an opportunity
to consider its position on the Association’s exemption
request. We therefore proceed to the substance of Rite Aid’s
challenge.

                              2.

     Rite Aid contends that, “[b]y restricting otherwise
permissible HIPAA communications,” the Declaratory Ruling
“conflicts with another federal law.” Rite Aid Br. 12 (quoting
NextWave Pers. Commc’ns, Inc. v. FCC, 254 F.3d 130, 149
(D.C. Cir. 2001)). It essentially argues that any partial
exemption of healthcare-related communications would have
been unlawful, because HIPAA—the exclusive source of
federal law on the disclosure of protected health
information—operates of its own force to supersede any
TCPA prohibition on healthcare calls. Rite-Aid is incorrect.
There is no obstacle to complying with both the TCPA and
HIPAA; “[t]he two statutes provide separate protections.”
Mais v. Gulf Coast Collection Bureau, Inc., 768 F.3d 1110,
1125 (11th Cir. 2014).

     Under HIPAA regulations, covered entities and their
business associates presumptively “may not use or disclose
protected health information.” 45 C.F.R. § 164.502(a). But
they are generally permitted to use or disclose that
information “for treatment, payment, or health care
operations.” Id. § 164.506(a). Rite Aid complains that the
partial exemption granted in the Declaratory Ruling conflicts
                              47
with HIPAA because it stops short of exempting billing- and
account-related communications—i.e., ones “for . . .
payment.” Id. But all that § 164.506(a)’s exclusion does is to
carve out an exception to civil and criminal liability for using
or disclosing protected health information. See 42 U.S.C.
§§ 1320d-5, 1320d-6.         It says nothing about the
Commission’s authority to exempt (or refrain from
exempting) certain kinds of calls from the TCPA’s consent
requirement.

     In confining the use of its exemption authority, the
Commission did not restrict communications that HIPAA
requires be permitted to flow freely. It simply declined to
make certain exchanges even less burdensome than they
would have been by default. If Rite Aid were correct,
healthcare providers could use ATDS equipment to bombard
nonconsenting wireless users with calls and texts concerning
outstanding charges without incurring TCPA liability.
Nothing in HIPAA commands such a result, and we see no
basis to interpret it to frustrate the TCPA in that way.

                               3.

    Finally, Rite Aid contends that the Declaratory Ruling’s
exemption for certain healthcare calls is arbitrary and
capricious. Neither of its suggested grounds is persuasive.

     a. Rite Aid first argues that the Commission failed to
explain its purported departure from its earlier practice of
exempting HIPAA-protected communications. In addition to
its restrictions on calls to wireless numbers, the TCPA also
forbids the use of an ATDS “to initiate any telephone call to
any residential telephone line using an artificial or
prerecorded voice to deliver a message without the prior
express consent of the called party,” unless one of three
                               48
exceptions applies.     47 U.S.C. § 227(b)(1)(B) (emphasis
added).

     In a 2012 Order, the Commission exempted from that
consent requirement “prerecorded health care-related calls to
residential lines, which are already regulated by” HIPAA. In
re Rules and Regulations Implementing the Telephone
Consumer Protection Act of 1991 (2012 Order), 27 FCC Rcd.
1830, 1837 ¶ 18 (2012). Some parts of the Order suggested
that its exemption reached no further than the one granted in
2015’s Declaratory Ruling for calls to wireless numbers.
Exempted calls were described as “promot[ing] important
communications . . . such as prescription refills and
immunization reminders,” id. at 1855 ¶ 63 n.192, and
“concern[ing] consumers’ health, not the purchase of a good
or service,” id. at 1856 ¶ 63 n.195. But the Order elsewhere
characterized its exemption as covering “all prerecorded
health care-related calls to residential lines that are subject to
HIPAA.” Id. at 1852 ¶ 57 (emphases added).

     The 2012 Order’s exemption was codified in 47 C.F.R.
§ 64.1200(a)(3)(v). That regulation did not use the phrase
“health care-related call[],” but instead referred to “‘health
care’ message . . . [as] defined in the HIPAA Privacy Rule, 45
C.F.R. § 160.103.” 47 C.F.R. § 64.1200(a)(3)(v). Likewise,
§ 160.103 does not mention the term “health care message.”
But it does define “health care” as “care, services, or supplies
related to the health of an individual.” 45 C.F.R. § 160.103.
That term includes, among many other things, “[s]ale or
dispensing of a drug, device, equipment, or other item in
accordance with a prescription.” Id. A “‘health care’
message” is presumably a message pertaining to any of the
topics that “health care” is defined to include. We assume for
present purposes that some calls concerning the “[s]ale . . . of
a drug . . . in accordance with a prescription” would relate to
                               49
“billing,” which the 2015 Declaratory Ruling did not exempt
from the consent requirement.

    Rite Aid is therefore correct that, in one sense, the 2012
exemption swept more broadly than the 2015 version. We
also accept that the 2012 Order cited a number of
“technology-agnostic justifications” for exempting all
prerecorded healthcare-related calls subject to HIPAA and
made to residential lines. Rite Aid Br. 5. For example, the
Commission believed that such calls “ensure continued
customer access to health care-related information” and
would not lead to “coercive or abusive” interactions. 2012
Order, 27 FCC Rcd. at 1853-54 ¶¶ 59-60.

     The relevant question is whether the Commission acted
arbitrarily and capriciously in affording a narrower exemption
for healthcare-related calls made to wireless numbers. We
find that it did not. Even if one might hypothesize “important
reasons for treating residential and wireless telephone lines
the same,” Rite Aid Br. 9, the TCPA itself presupposes the
contrary—that calls to residential and wireless numbers
warrant differential treatment.

     Unlike with the autodialer restrictions on calls to wireless
numbers, callers are free to use ATDS equipment to dial
residential lines as long as no “artificial or prerecorded voice”
is used. 47 U.S.C. § 227(b)(1)(B). The statute itself
contemplates that calls to wireless numbers “tread [more]
heavily upon . . . consumer privacy interests.” 2012 Order, 27
FCC Rcd. at 1855 ¶ 63. That concern directly informed the
2015 exemption’s scope: the Commission concluded that
messages “not critical to a called party’s healthcare . . . do not
justify setting aside a consumer’s privacy interests.” 2015
Declaratory Ruling, 30 FCC Rcd. at 8031 ¶ 146.
                               50
     In short, there is nothing inherently contradictory about
easing restrictions on certain kinds of calls to landlines, but
not to cellular phones. And Rite Aid fails to mention another
variable that confounds direct comparisons between the two
exemptions. As codified, the 2012 exemption applies only to
calls that “us[e] an artificial or prerecorded voice to deliver a
message,” 47 C.F.R. § 64.1200(a)(3); the Declaratory
Ruling’s exemption is not so limited. We therefore reject Rite
Aid’s first arbitrary-and-capricious challenge.

     b. Lastly, Rite Aid argues that the Commission acted
arbitrarily by failing to recognize that all healthcare-related
calls satisfy the TCPA’s “emergency purposes” exception to
the consent requirement. As used in the Act, “[t]he term
emergency purposes means calls made necessary in any
situation affecting the health and safety of consumers.” 47
C.F.R. § 64.1200(f)(4). But Rite Aid identifies no calls
satisfying that exception that were not already subject to the
2015 exemption. It would be implausible to conclude that
calls concerning “telemarking, solicitation, or advertising
content, or which include accounting, billing, debt-collection,
or other financial content” are made for “emergency
purposes.” 2015 Declaratory Ruling, 30 FCC Rcd. at 8031
¶ 146. Even if accounting systems are in some sense
“necessary” to the continued provision of healthcare,
“[t]imely delivery of these types of messages is not critical”
to that goal. Id. (emphasis added).

     In marked contrast, the Commission recently exempted
calls concerning certain time-sensitive risks to students’
health and safety in the school setting. That list of scenarios
included “weather closures, fire, . . . threats,” “dangerous
persons, health risks (e.g., toxic spills), and unexcused
absences.” In re Rules and Regulations Implementing the
Telephone Consumer Protection Act of 1991, 31 FCC Rcd.
                              51
9054, 9061 ¶ 17, 9063 ¶ 21 (2016). In declining a request to
interpret the emergency-purposes exception far more
expansively, we are guided by its role in the statutory scheme.
Consumers may find themselves wholly unable to stave off
calls satisfying the exception. That is because, by definition,
such calls fall outside the TCPA’s consent framework; callers
can make them even if recipients are known to object.
Advertisements, solicitations, and post-treatment financial
communications do not arise from the sorts of “emergencies”
that would justify suspending the TCPA’s consent regime.

     The Commission was empowered to draw the distinction
it did, and it adequately explained its reasons for doing so.
We therefore reject Rite Aid’s arbitrary-and-capricious
challenge.

                      *   *   *    *   *

     For the foregoing reasons, we grant in part and deny in
part the petitions for review.

                                                   So ordered.
