                FOR PUBLICATION

  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT


RONALD FOURNIER,                          No. 12-15478
                            Plaintiff,
                                            D.C. No.
                and                      2:08-cv-02309-
                                              ROS
DELORES BERG ; THOMAS DICECCO ,
JR.,
              Plaintiffs-Appellants,        OPINION

                 v.

KATHLEEN SEBELIUS, Secretary of
the Department of Health and
Human Services,
                Defendant-Appellee.


     Appeal from the United States District Court
              for the District of Arizona
    Roslyn O. Silver, Chief District Judge, Presiding

               Argued and Submitted
         March 5, 2013—Pasadena, California

                  Filed May 31, 2013
2                     FOURNIER V . SEBELIUS

    Before: Alfred T. Goodwin, Kim McLane Wardlaw,
           and Ronald M. Gould, Circuit Judges.

                     Opinion by Judge Gould


                           SUMMARY*


                             Medicare

    The panel affirmed the district court’s judgment affirming
the Secretary of Health and Human Services’ decisions
denying plaintiffs’ claims for Medicare coverage for dental
services.

    Plaintiffs are Medicare beneficiaries who suffer from
medical conditions that caused significant dental problems,
and they received dental services to correct those problems.
The panel held that the Medicare Act under which the
Secretary denied coverage was ambiguous on the question
plaintiffs raised. The panel further held that Chevron
deference applied, and the Secretary’s interpretation of the
statute was reasonable. Finally, the panel held that the
Secretary’s denial of coverage did not violate plaintiffs’ equal
protection rights under the Fifth Amendment.




  *
    This summary constitutes no part of the opinion of the court. It has
been prepared by court staff for the convenience of the reader.
                   FOURNIER V . SEBELIUS                      3

                         COUNSEL

Gill Deford (argued), Wey-Wey Kwok, Alice Bers, Center
for Medicare Advocacy, Inc., Willimantic, Connecticut, for
Plaintiffs-Appellants.

Sushma Soni (argued), Attorney, Civil Division, Stuart F.
Delery, Acting Assistant Attorney General, Dennis K. Burke,
United States Attorney, Michael S. Raab, Attorney, Civil
Division, United States Department of Justice, Washington,
D.C., for Defendant-Appellee.

Ruth Szanto, Arizona Center for Disability Law, Phoenix,
Arizona, for Amici Curiae.


                          OPINION

GOULD, Circuit Judge:

    Appellants Delores Berg and Thomas DiCecco are
Medicare beneficiaries who suffer from medical conditions
that caused significant dental problems, and they received
dental services to correct those problems. But the Secretary
of the Department of Health and Human Services (HHS)
denied coverage for those services. Appellants contend that
this denial was premised on the Secretary’s unreasonable
interpretation of the Medicare Act, which contravenes the
intent of Congress and violates Appellants’ right to equal
protection under the Fifth Amendment. We affirm the district
court, holding (1) that the statute under which the Secretary
denied coverage is ambiguous on the question Appellants
raise; (2) that Chevron deference applies; (3) that the
Secretary’s interpretation of the statute is reasonable; and (4)
4                      FOURNIER V . SEBELIUS

that the denial does not violate Appellants’ Fifth Amendment
rights.1

                                     I

     Berg is a Medicare Advantage beneficiary. She suffers
from Sjogren’s Syndrome, which has left her unable to
produce saliva. As a result, she lost teeth, her gums
deteriorated, and her bite collapsed. Berg’s lack of saliva
made her prone to gum infections, which put her at risk of a
life-threatening heart infection. In response to the grave
conditions and risks caused by Sjogren’s syndrome, Berg’s
dentist recommended a treatment plan that would “develop
and reconstruct a leveled bite,” with procedures including a
partial denture, several crowns, and bridgework. Berg
underwent the recommended procedures on February 27,
2008, at a total cost of $28,750.00.

    Berg submitted a claim for these services to her Medicare
Advantage provider. Her provider denied the claim because
Berg was enrolled in a plan that did not cover “[r]outine
dental care (such as cleanings, fillings, or dentures) or other
dental services.” Berg’s provider sent her appeal to an
independent outside review entity, which told Berg that the
dental services related to Sjogren’s syndrome do not fall
within the limited dental coverage of her Medicare Advantage
plan and denied her appeal. Berg then appealed to an

    1
    Appellants do not directly challenge the Secretary’s final decision on
their individual claims for benefits but instead challenge the policy leading
to those unfavorable rulings. Because we affirm the district court on both
of Appellants’ substantive claims, we need not and do not reach their
claim that the district court erred in concluding that putative class
members did not qualify for waiver of exhaustion of administrative
remedies.
                   FOURNIER V . SEBELIUS                      5

Administrative Law Judge (“ALJ”), who ruled that the
services Berg received were excluded by Medicare’s dental-
services exclusion. Although the plan representatives and the
ALJ acknowledged that Berg’s dental problems stemmed
from her Sjogren’s syndrome, the ALJ concluded that the
services at issue did not fall under any exception to the dental
exclusion because Berg’s “dental work was the primary
procedure, rather than necessary to or incident to any
Medicare covered procedure.” The Medicare Appeals
Council (“MAC”) adopted the ALJ’s decision and denied
Berg’s appeal, explaining, “Services performed in connection
with the care, treatment, filling, removal, or replacement of
teeth or structures directly supporting teeth are not covered
and, to the extent coverage is provided, it is only under
limited circumstances not applicable to this case.”

     Thomas DiCecco, Jr., is a Medicare beneficiary under
Parts A and B. In 1996, several years before becoming
eligible for Medicare, DiCecco received an allogeneic bone-
marrow transplant to treat chronic myelogenous leukemia.
He received a donor lymphocyte infusion in June 1999. As
a result of these treatments, DiCecco developed graft-versus-
host disease, with a resulting loss of salivary function. As it
did with Berg, DiCecco’s lack of saliva led to tooth loss.
DiCecco’s tooth decay was so severe that it caused “certain
teeth to just crack off,” and forced him to use a feeding tube
for nearly a year. More than a decade after DiCecco’s bone-
marrow transplant, his dentist prescribed a course of
treatment, responding to the graft-versus-host disease with
frequent examinations and restorative dental work such as
fillings and crowns. DiCecco had this treatment from April
to July 2008. DiCecco then submitted a claim for
reimbursement for resin, crown, and fluoride treatments to his
Medicare Part B contractor. His contractor denied the claim
6                    FOURNIER V . SEBELIUS

in full, and an independent contractor upheld the denial.
DiCecco appealed to an ALJ, who recognized that DiCecco
needed the dental care because of his graft-versus-host
disease but upheld the denial because “dental services are
excluded from Medicare coverage regardless of the medical
need for those services.” The MAC adopted the ALJ’s
decision and acknowledged that DiCecco’s need for dental
services was provoked by a medical condition. But the MAC
explained that the relationship between DiCecco’s graft-
versus-host disease and his dental services does not, by itself,
qualify the dental services for Medicare coverage. DiCecco’s
treatments would be covered only if they were furnished
along with a covered procedure that was performed by the
dentist on the same occasion.

    Berg and DiCecco joined a lawsuit filed by Ronald
Fournier, who raised similar claims to those of Berg and of
DiCecco.2 The plaintiffs challenged the MAC decisions,
which were the Secretary’s final decisions in their cases, and
sought declaratory and injunctive relief advocating the views
that the Secretary’s decision to deny coverage for their
extraordinary, medically related dental services violated HHS
policy, the Medicare Act, and their right to equal protection.
The district court held (1) that substantial evidence supported
the Secretary’s decisions denying coverage to Berg and
DiCecco, (2) that the Secretary’s statutory interpretation
excluding coverage was reasonable, and (3) that the
Secretary’s policy does not violate the equal protection
guarantee in the Fifth Amendment’s due process clause. This
appeal followed.


    2
   Fournier received a favorable ruling from an ALJ before the district
court issued its order, so Fournier’s claims were dismissed as moot.
Fournier v. Sebelius, 839 F. Supp. 2d 1077, 1081 (D. Ariz. 2012).
                   FOURNIER V . SEBELIUS                    7

                             II

    This appeal centers on the broad exclusion of dental
services from Medicare coverage, so we discuss the
development of that exclusion. Congress established
Medicare in 1965 as Title XVIII of the Social Security Act
(“Medicare Act”). Pub. L. No. 89-97, 79 Stat. 286 (1965).
Medicare provides medical services to (1) the aged, (2) the
disabled, and (3) those who have end-stage renal (kidney)
disease. 42 U.S.C. § 1395c. The Secretary of Health and
Human Services administers the program, and she has
authority to prescribe necessary regulations, § 1395hh(a)(1),
and determine which claims will be covered, § 1395ff(a).
The Secretary may issue National Coverage Determinations
to define what services are considered reasonable and
necessary. § 1395ff(f)(1)(B).

    Medicare provides institutional care, including inpatient
hospital services, through Part A, § 1395d(a), and authorizes
payment for supplemental and outpatient services in Part B,
§ 1395k. Part C, known as Medicare Advantage, allows
beneficiaries to receive services authorized under Parts A and
B through managed-care or fee-for-service plans. § 1395w-
22(a)(1)(A), (a)(1)(B)(i).

   Medicare coverage is broadly limited to services that
are medically “reasonable and necessary.”                 See
§ 1395y(a)(1)(A)–(C). Medicare coverage is also subject to
specific restrictions, one of which, prominent here, excludes
most dental services from reimbursement. That exclusion
denies payment for any expenses incurred:

       for services in connection with the care,
       treatment, filling, removal, or replacement of
8                  FOURNIER V . SEBELIUS

       teeth or structures directly supporting teeth,
       except that payment may be made under part
       A of this subchapter in the case of inpatient
       hospital services in connection with the
       provision of such dental services if the
       individual, because of his underlying medical
       condition and clinical status or because of the
       severity of the dental procedure, requires
       hospitalization in connection with the
       provision of such services;

§ 1395y(a)(12). The exclusion, without the exception for
inpatient services under Part A, was included in the initial
form of the Medicare Act. See Pub. L. No. 89-97,
§ 1862(a)(12), 79 Stat. 286, 325 (1965). The Senate Report
accompanying the Medicare Act said that this exclusion was
intended “to make clear that the services of dental surgeons
covered under the bill are restricted to complex surgical
procedures” and that “routine dental treatment—filling,
removal, or replacement of teeth or treatment of structures
directly supporting the teeth—would not be covered.”
S. Rep. No. 89-404, at 49 (1965), reprinted in
1965 U.S.C.C.A.N. 1943, 1989–90. This explanation moves
us towards the core of the problem presented on this appeal.
When the Secretary first promulgated regulations under the
dental exclusion in § 1395y(a)(12), she added the word
“routine” to the statutory exclusion, excluding coverage for
“[r]outine dental services in connection with the care,
treatment, filling, removal, or replacement of teeth, or
structures directly supporting the teeth.” 31 Fed. Reg. 13534,
13535 (Oct. 20, 1966).

   Congress also limited coverage for dental services in a
second way: by restricting the definition of “physician.” The
                       FOURNIER V . SEBELIUS                              9

Medicare Act distinguished between complex, covered dental
procedures and common, excluded procedures by defining
“physician” to include dentists and oral surgeons only when
they performed “(A) surgery related to the jaw or any
structure contiguous to the jaw or (B) the reduction of any
fracture of the jaw or any facial bone.” Pub. L. No. 89-97,
§ 1861(r)(2), 79 Stat. 286, 321 (1965).

    Covered services, such as surgery related to the jaw, often
require individual procedures, such as tooth removal, that
standing alone would not be covered as primary procedures.
As a result, the Secretary needed to determine when a dental
service was provided “in connection with” a covered primary
procedure such that the dental service would be covered.
Shortly after passage of the Medicare Act, the Director of the
Bureau of Health Insurance answered this question in policy
guidance to clarify the coverage of secondary dental services
in his Intermediary Letter No. 193 of January 30, 1967.

    The Director reasoned that because a dentist was defined
as a “physician” only when performing surgery “related to the
jaw or structures contiguous to the jaw (including the
reduction of any fracture of the jaw or any facial bone), all
such surgical procedures performed by a dentist” would be
covered unless specifically excluded. By contrast, any
services rendered in connection with the examination, care,
treatment, filling, removal, or replacement of teeth and any
services rendered in connection with the examination, care,
or treatment of structures directly supporting the teeth were
excluded.3 The Director explained that Medicare would


 3
   According to the Secretary, “‘[s]tructures directly supporting the teeth’
means the periodontium, which includes the gingivae, dentogingival
junction, periodontal membrane, cementum of the teeth, and alveolar
10                     FOURNIER V . SEBELIUS

cover these procedures when performed on the same occasion
by a dentist “as an incident to and as an integral part of a
covered procedure or service performed by him.” If an
excluded service were the primary procedure, however, that
procedure and any adjuncts “would not be covered regardless
of the complexity or difficulty of the procedure.” This is
known as the “same physician rule.”4 See Wood v.
Thompson, 246 F.3d 1026, 1030 (7th Cir. 2001).

    Congress revisited the exclusion of primary dental
services in 1972, when it amended § 1395y(a)(12) to give
coverage for dental services “under part A in the case of
inpatient hospital services in connection with a dental
procedure where the individual suffers from impairments of
such severity as to require hospitalization.” Pub. L. No.
92-603, § 256(c), 86 Stat. 1329, 1447 (1972). The next year,
Congress again amended this subsection to clarify the
coverage of inpatient dental services, allowing coverage only
if the patient’s “underlying medical condition and clinical
status require[d] hospitalization in connection with the
provision of such services.” Pub. L. No. 93-233, § 18(k)(3),


process.” Centers for Medicare & Medicaid Servs., Publ’n No. 100-02,
Medicare Benefit Policy Manual, ch. 15, § 150, at 134.

  4
     The same-physician rule is often described as an exception to the
exclusion of coverage for dental procedures as primary services under
42 U.S.C. § 1395y(a)(12). See Fournier v. Sebelius, 839 F. Supp. 2d
1077, 1081 (D. Ariz. 2012) (“[T]to be covered by [the] exception, the
dental services would have to be furnished along with another covered
procedure performed by the dentist on the same occasion.”) (quoting the
MAC). Section 1395y(a)(12), however, excludes coverage for services
“in connection” with dental services. It does not provide, limit, or
consider dental services that are provided “in connection” with services
“furnished as an incident to a physician’s professional service” as defined
in 42 U.S.C. § 1395x(s)(2)(A).
                   FOURNIER V . SEBELIUS                     11

87 Stat. 947, 970 (1973). In response to these amendments,
the Secretary issued a new regulation “[t]o conform the
regulatory language regarding hospital admissions for
excluded dental services with the statutory language.”
39 Fed. Reg. 28622, 28623 (Aug. 9, 1974). This 1974
revision removed the word “routine” from the coverage
exclusion and noted that the 1973 statutory amendment, Pub.
L. 93-233, § 18(k), “confirmed the substantive position taken
in the proposed regulations.” Id.; see also 42 C.F.R.
§ 411.15(i).

    In 1980, Congress amended the Medicare Act to expand
the role of dentists in two ways. First, the definition of
“physician” was amended to include “a doctor of dental
surgery or of dental medicine who is legally authorized to
practice dentistry by the State in which he performs such
function and who is acting within the scope of his license
when he performs such functions.” Pub. L. No. 96-499,
§ 936(a), 94 Stat. 2599 (1980); see also 42 U.S.C. § 1395x(r).
The accompanying House Report stated that “there are some
services which are covered under Medicare only if performed
by a physician . . . but are not covered when furnished by a
dentist.” H.R. Rep. No. 96-1167 at 372 (1980), reprinted at
1980 U.S.C.C.A.N. 5526, 5735. The amended language
“provide[d] the same coverage for services performed by a
dentist . . . that is provided for services performed by
physicians.” Id.

    Second, Congress granted admitting privileges to dentists
and expanded coverage of inpatient dental services. Before
the 1980 amendment, inpatient dental services were covered
only when a patient was hospitalized for an underlying,
nondental condition. See id. Coverage was “precluded
where, in the judgment of the patient’s dentist, the severity of
12                 FOURNIER V . SEBELIUS

the dental procedure alone require[d] hospitalization.” Id.
Congress amended the section to cover “hospital stays based
on a dentist’s (or physician’s) certification that hospital
inpatient services are necessary for the performance of
noncovered dental procedures either because of the severity
of the dental procedure or the patient’s underlying condition
warrants such hospitalization.” Id. at 5735–36. These
changes were meant to bring parity to the role of dentists and
provide for greater inpatient dental coverage under Part A,
not expand the provision of outpatient dental services under
Part B, so the “exclusion of routine dental services . . .
remain[ed] in effect.” Id. at 5735.

    These changes to the role of dentists did not change the
scope of coverage of dental services on an outpatient basis,
and the text of the dental exclusion has not changed since
passage, apart from the allowance for inpatient coverage
under Part A. Compare Pub. L. No. 89-97, § 1862(a)(12),
79 Stat. 286, 325, with 42 U.S.C. § 1395y(a)(12). Medicare
contractors must still determine whether dental services are
provided “in connection” with a covered, primary service. As
a result, the same-physician rule remains in effect. The
Centers for Medicare and Medicaid Services (CMS)
Medicare Benefit Policy Manual (CMS Manual) describes the
rule in language similar to that found in the 1967
Intermediary Letter No. 193, explaining:

       If an otherwise noncovered procedure or
       service is performed by a dentist as incident to
       and as an integral part of a covered procedure
       or service performed by the dentist, the total
       service performed by the dentist on such an
       occasion is covered.
                      FOURNIER V . SEBELIUS                           13

Centers for Medicare & Medicaid Servs., Publ’n No. 100-02,
Medicare Benefit Policy Manual, ch. 15, § 150, at 134.; see
also id. ch. 16 § 140.

    An exception to the same-physician rule allows for
reimbursement of dental services provided in preparation for
a covered procedure performed by a different physician: the
extraction of teeth to prepare a patient’s jaw for radiation
treatment of neoplastic disease. Id. at ch. 15, § 150. Most
often, a dentist will extract the patient’s teeth and a
radiologist will administer the radiation treatments. Id. In a
similar situation, Medicare covers dental examinations on an
inpatient basis as part of a work-up before kidney transplant
surgery. Centers for Medicare & Medicaid Servs., Publ’n
No. 100-03, Medicare National Coverage Determinations
Manual, § 260.6. This examination is only provided on an
inpatient basis, so it now likely falls under the general
allowance for inpatient services under Part A.5 In both
situations, however, the purpose of the dental procedure is not
the care of teeth or structures supporting teeth but the
preparation for a subsequent, covered procedure.

                                  III

    We have jurisdiction under 42 U.S.C. §§ 405(g), 1395w-
22(g)(5), and 1395ff(b)(1)(A) and 28 U.S.C. § 1291. We
review a district court’s decision upholding the MAC’s


  5
     This second situation is nevertheless described as an exception or
corollary to the same-physician rule. See Wood, 246 F.3d at 1030. In
addition to the potential provision of this service under Part A, Kidney-
transplant surgery is in a unique category under Medicare because end-
stage renal disease is the only condition that guarantees Medicare
eligibility. See 42 U.S.C. § 1395rr.
14                 FOURNIER V . SEBELIUS

decisions de novo. Conahan v. Sebelius, 659 F.3d 1246, 1249
(9th Cir. 2011). We review de novo a district court’s
constitutional rulings, Wright v. Incline Vill. Gen.
Improvement Dist., 665 F.3d 1128, 1133 (9th Cir. 2011), as
well as its decisions on questions of statutory interpretation,
Portland Adventist Med. Ctr. v. Thompson, 399 F.3d 1091,
1095 (9th Cir. 2005).

                              IV

    Appellants contest the MAC’s rulings denying coverage
for their dental services by challenging the Secretary’s
underlying policy decision to exclude dental procedures that
are not performed at the same time and by the same dentist as
a covered procedure. Appellants contend (1) that the
Secretary has not carried out Congress’s intent to cover
complex surgical procedures and (2) that the Secretary’s
coverage policy is irrational and thus violates the equal
protection component of the Due Process Clause of the Fifth
Amendment. We consider first statutory interpretation, and
then the constitutional challenge.

                              A

    When we review an agency’s interpretation of a statute
that it is charged with administering, “[f]irst, always, is the
question whether Congress has directly spoken to the precise
question at issue.” Chevron, U.S.A., Inc. v. Natural Res. Def.
Council, Inc., 467 U.S. 837, 842 (1984). “If the intent of
Congress is clear, that is the end of the matter; for the court,
as well as the agency, must give effect to the unambiguously
expressed intent of Congress.” Id. at 842–43. But if “the
statute is silent or ambiguous with respect to the specific
issue,” we will not “impose [our] own construction on the
                      FOURNIER V . SEBELIUS                           15

statute.” Id. at 843. Instead, we ask “whether the agency’s
answer is based on a permissible construction of the statute.”
Id. If the agency’s construction is permissible, we defer to it.
See Palomar Med. Ctr. v. Sebelius, 693 F.3d 1151, 1164 (9th
Cir. 2012).

    Before we address whether in the statute Congress has
spoken clearly, we must identify the precise question at issue.
 Appellants do not allege that they received dental services in
connection with a covered procedure. Because they do not,
the same-physician rule does not come into play, and any
ambiguity in the Secretary’s implementation of that rule is
not relevant here.6

    Appellants also do not allege that they received dental
care on an inpatient basis, and they do not seek
reimbursement under Part A. As a result, they do not qualify
for § 1395y(a)(12)’s inpatient exception. Appellants received
outpatient services and sought reimbursement under Part B,
so they cannot benefit from the coverage rules provided for
inpatient care under Part A. Accord Chipman v. Shalala,
90 F.3d 421, 422–23 (10th Cir. 1996). Any ambiguity in the
inpatient-coverage provision does not reach Appellants.

   Appellants are in a third category. They received primary
dental services on an outpatient basis and sought coverage
under Part B. Appellants contend that those services should
be covered because they were “medically necessary” to


 6
    One of our sister circuits held § 1395y(a)(12) to be ambiguous in that
context, see Wood, 246 F.3d at 1031–32. After examining the rule, the
Seventh Circuit applied Chevron deference and concluded that the
Secretary’s interpretation of the same-physician rule was reasonable. Id.
at 1035.
16                FOURNIER V . SEBELIUS

prevent potentially fatal heart infections. The Secretary
disagrees, arguing that § 1395y(a)(12) unambiguously rejects
Appellants’ claims: Services “in connection with the care,
treatment, filling, removal, or replacement of teeth or
structures directly supporting teeth” are excluded from
coverage, so primary dental services that are not provided on
an inpatient basis are excluded by the statute. According to
the Secretary, the relationship between Appellants’ services
and their risk of infection is irrelevant.

    Having distinguished Appellants’ situation from related
questions about dental coverage under Medicare, we do not
think that “Congress has directly spoken to the precise
question at issue.” Chevron, 467 U.S. at 842. Section
1395y(a)(12) prohibits Medicare coverage of expenses for
services “in connection” with the care of the teeth. It is
arguable, however, that the Secretary could interpret
Appellants’ services to have been provided not “in connection
with” the care and treatment of teeth, but rather “in
connection with” a medical need to prevent life-threatening
heart infections. Viewed in this light, the services provided
here could plausibly be viewed as either in connection with
the care of teeth or with alleviating a symptom caused by a
serious prior disease, namely Sjogren’s Syndrome or graft-
versus-host disease. We can see that there are fair arguments
on both sides of the issue and conclude that the statute is
ambiguous. Accordingly, we turn to the second step of
Chevron. See 476 U.S. at 843.

                             B

    Having concluded that § 1395y(a)(12) is ambiguous as to
the extent of the dental-services exclusion, we now address
whether the Secretary’s construction of that exclusion is
                   FOURNIER V . SEBELIUS                     17

reasonable. See id. The Secretary did not issue her
interpretation through notice-and-comment rulemaking or
formal adjudication, so we must first determine what level of
deference we should give to her interpretation. See United
States v. Mead Corp., 533 U.S. 218, 229 (2001). Appellants
contend that the Secretary’s interpretation of § 1395y(a)(12)
does not merit Chevron deference because the interpretation,
as published in the CMS Manual, does not carry the force of
law. Instead, Appellants suggest that the Secretary’s
interpretation is entitled to respect only to the extent that it
has the “power to persuade” under Skidmore v. Swift & Co.
323 U.S. 134, 140 (1944). See Christensen v. Harris County,
529 U.S. 576, 587 (2000) (“Interpretations such as those in
opinion letters—like interpretations contained in policy
statements, agency manuals, and enforcement guidelines, all
of which lack the force of law—do not warrant Chevron-style
deference.”). Under that standard, Appellants believe, the
Secretary’s interpretation is unpersuasive.

    The Secretary agrees that her interpretation in the CMS
Manual does not by itself carry the force of law. See
42 C.F.R. § 405.1062(a) (“ALJs and the MAC are not bound
by . . . manual instructions.”). Instead, the Secretary explains
that her interpretation deserves Chevron deference because
the process of adjudication leading to the MAC’s decisions
was “provided for by Congress” and the Secretary’s
interpretation was given effect through this “relatively formal
administrative procedure.” Mead, 533 U.S. at 230.

    Under Mead, we will give Chevron deference to an
agency’s interpretation of a statute “only when: (1) ‘it appears
that Congress delegated authority to the agency generally to
make rules carrying the force of law,’ and (2) ‘the agency
interpretation claiming deference was promulgated in the
18                 FOURNIER V . SEBELIUS

exercise of that authority.’” Price v. Stevedoring Servs. of
Am., Inc., 697 F.3d 820, 833 (9th Cir. 2012) (en banc)
(quoting Mead, 533 U.S. at 226–27).

    The Secretary’s interpretation meets the first prong of the
Mead test. The Secretary has general rulemaking authority
under § 1395hh(a)(1). Congress decided that Medicare
should pay for reasonable and necessary medical expenses,
but it also restricted coverage of outpatient dental care.
Congress delegated to the Secretary the authority to
“promulgate regulations and make initial determinations with
respect to benefits” within the bounds of these provisions.
42 U.S.C. § 1395ff(a). The authority to promulgate
regulations indicates that Congress delegated to the Secretary
to make rules carrying the force of law. See Mead, 533 U.S.
at 229 (citing EEOC v. Arabian Am. Oil Co., 499 U.S. 244,
257 (1991) (explaining that we give no Chevron deference to
agency guideline where congressional delegation did not
include the power to “promulgate rules or regulations”)).

    Addressing the second prong of Mead, we ask whether
the Secretary’s interpretation of the dental exclusion “was
promulgated in the exercise of that authority [to make rules
carrying the force of law].” Id. at 227. The answer “depends
on the form and context of that interpretation.” Price,
697 F.3d at 826. That the Secretary reached her interpretation
“through means less formal than ‘notice and comment’
rulemaking does not automatically deprive that interpretation
of the judicial deference otherwise its due.” Barnhart v.
Walton, 535 U.S. 212, 221 (2002). The Secretary’s
interpretation of the dental exclusion is similar in both form
and context to the interpretation given Chevron deference in
Barnhart, id. at 225, and we follow Barnhart to conclude the
                    FOURNIER V . SEBELIUS                     19

Secretary’s interpretation meets the second prong of the Mead
test.

    In Barnhart, the Supreme Court reversed a Fourth Circuit
decision holding that a section of the Social Security Act
forbade the Secretary’s interpretation of the meaning of the
word “inability” in the definition of “disability.” Id. at 214.
The statute defined “disability” as an “inability to engage in
any substantial gainful activity . . . which has lasted or can be
expected to last for a continuous period of not less than 12
months.” Id. (emphasis omitted) (quoting 42 U.S.C.
§ 423(d)(1)(A)). Under the Secretary’s interpretation, this
duration requirement was prospective if the inability was
ongoing at the time of adjudication. But if an applicant’s
inability resolved itself in less than 12 months, the applicant
would not be found disabled and would receive no benefits,
even if the inability were one that initially might have been
expected to last that long. Id. The Supreme Court first
examined and upheld this definition as the agency’s
interpretation of its own regulation. Id. at 217 (citing Auer v.
Robbins, 519 U.S. 452, 461 (1997)).

    The petitioner in Barnhart objected to the Court’s
application of Auer, however, because the regulation in
question came into effect long after the agency denied his
claim for benefits, possibly in response to the litigation. Id.
at 221; see Walton v. Apfel, 235 F.3d 184, 188 n.6 (4th Cir.
2000), rev’d sub nom. Barnhart, 535 U.S. at 221 (the
proposed regulation did not apply retroactively). But the
Court explained that the agency’s long-held interpretation
would warrant Chevron deference even if it had not been
20                     FOURNIER V . SEBELIUS

bolstered by the rulemaking. Id.7 The Court reasoned that
“the interstitial nature of the legal question, the related
expertise of the Agency, the importance of the question to
administration of the statute, the complexity of that
administration, and the careful consideration the Agency has
given the question over a long period of time all indicate that
Chevron provides the appropriate legal lens through which to
view the legality of the Agency interpretation here at issue.”
Barnhart, 535 U.S. at 222 (citing Mead).

    The Secretary’s interpretation here exhibits those factors.
The legal question is interstitial: the dental exclusion “is
clear, with clear exceptions,” Wood, 246 F.3d at 1035, and
the Secretary’s interpretation fills the interstices dividing the
exceptions from the exclusion. The rule limiting coverage is
important to the Secretary’s administration of Medicare given
the scarce resources available and the “vast number of claims
that [Medicare] engenders.” Barnhart, 535 U.S. at 225. That
vast number of claims, each of which involves distinct
medical facts, speaks also to the complexity of administering
Medicare “and the consequent need for agency expertise and
administrative experience.” Id.

    The origins and legal contexts of the two interpretations
are also similar. The interpretation in Barnhart originated in
a disability-insurance letter, was later published in a state

 7
   Appellants contend that this section of Barnhart was dicta because the
Court decided the outcome under Auer. Even if this were true, we afford
“considered dicta from the Supreme Court . . . a weight that is greater than
ordinary judicial dicta as prophecy of what that Court might hold.” United
States v. Montero-Camargo, 208 F.3d 1122, 1132 n.17 (9th Cir. 2000) (en
banc). Given the similarities between Appellants’ situation and Barnhart,
we choose not to ignore the Supreme Court’s reasoned guidance in that
case.
                   FOURNIER V . SEBELIUS                    21

disability-insurance manual, and was included in Social
Security Ruling 86-52 before being issued as a regulation
following notice-and-comment rulemaking. Id. at 219–20.
Here, the Secretary first issued her interpretation in an
intermediary letter and later published it in a manual. Social
Security rulings, like interpretations in the CMS Manuals, do
not have the force of law; both are interpretative rules
constituting the agencies’ interpretations of the statutes
they administer. Compare Chavez v. Dep’t of Health &
Human Servs., 103 F.3d 849, 851 (9th Cir. 1996) (Social
Security rulings), with Cmty. Hosp. of Monterey Peninsula v.
Thompson, 323 F.3d 782, 788 (9th Cir. 2003) (CMS
Manual provisions). Both gain the force of law through the
process of adjudication of a “vast number of claims” under
§ 405(b). See 42 U.S.C. § 1395w-22(g)(5) (incorporating
administrative hearing and judicial review provisions of
§ 405(b) and (g) from Social Security into Medicare);
42 U.S.C. § 1395ff(b)(1)(A) (same).

    In Barnhart, the Court gave particular weight to the long
history and stability of the interpretation in question. The
agency in Barnhart first adopted its interpretation of
“inability” in 1957, and the Court noted that it “will normally
accord particular deference to an agency interpretation of
‘longstanding’ duration.” 535 U.S. at 220 (citing North
Haven Bd. of Ed. v. Bell, 456 U.S. 512, 522, n.12 (1982)).
Here, the Secretary first adopted her interpretation of the
exclusion of primary dental services in her 1967 Intermediary
Letter No. 193. More than eleven years have now passed
since the Supreme Court decided Barnhart, so the Secretary’s
interpretation of the dental exclusion is even older than the
agency’s interpretation of the word “inability” was when the
Court decided Barnhart. In addition to the weight of years of
consistent administrative interpretation, the Secretary’s
22                 FOURNIER V . SEBELIUS

interpretation of the dental exclusion was issued shortly after
passage of the Medicare Act. See Health Insurance for the
Aged Act, Pub. L. No. 89–97, tit. I, 79 Stat. 290 (1965). Such
a nearly contemporaneous construction is entitled to
significant deference. See Good Samaritan Hosp. v. Shalala,
508 U.S. 402, 414 (1993).

    As in Barnhart, the Secretary’s interpretation of the
dental exclusion is a half-century old interpretation given
effect through a system of adjudication authorized under
§ 405(b). Moreover, the Secretary’s interpretation shows the
same factors deemed critical in Barnhart. These similarities
“all indicate that Chevron provides the appropriate legal lens
through which to view the legality of the [Secretary’s]
interpretation here at issue.” Barnhart, 535 U.S. at 222.

    Appellants contend that the Secretary’s interpretation has
been inconsistent and is “entitled to considerably less
deference than a consistently held agency view.” I.N.S. v.
Cardoza-Fonseca, 480 U.S. 421, 446 n.30 (1987) (internal
quotation and citation omitted). But when Appellants
describe the Secretary’s interpretation as inconsistent, they
refer not to the challenged interpretation—the policy
guidance on outpatient primary dental procedures—but to
42 C.F.R. § 411.15(i), the regulation that paraphrases the
statutory dental exclusion in § 1395y(a)(12). In 1974, the
Secretary removed the word “routine” from the description of
dental services excluded from coverage. The Secretary made
that change to accommodate the new exception for inpatient
services under Part A. See 39 Fed. Reg. 28622, 28623 (Aug.
9, 1974). The policy guidance at issue here did not change;
it has been consistent since 1967. As discussed in Section
IV(A) above, Appellants’ claims do not implicate the same-
physician rule or the inpatient exception. Changes to the
                       FOURNIER V . SEBELIUS                           23

Secretary’s guidance on those questions do not undermine her
interpretation here, and Cardoza-Fonseca does not reduce the
deference we will give to this long-standing, “consistently
held agency view.” 480 U.S. at 446 n.30. Like the United
States Court of Appeal for the Seventh Circuit in Wood, we
conclude that the Secretary’s interpretation of § 1395y(a)(12)
warrants Chevron deference. See 246 F.3d at 1035.8

Having so concluded, and in light of our prior conclusion that
the statute is ambiguous, we must decide whether the
Secretary’s interpretation is a reasonable one. Congress
required the Secretary to deny payment for “services in
connection with the care, treatment, filling, removal, or
replacement of teeth or structures directly supporting teeth”
that are not provided on an inpatient basis to hospitalized
patients. 42 U.S.C. § 1395y(a)(12). She has done so since
1967 by reading “services in connection with” to refer to
services related to dental procedures provided as primary
services based on her reasonable definition of “structures
directly supporting teeth.” In the decades since, “Congress
has frequently amended or reenacted the relevant provisions”
without altering this exclusion, “provid[ing] further evidence
. . . that Congress intended the Agency’s interpretation, or at
least understood the interpretation as statutorily permissible.”


  8
    The Second Circuit considered a different interpretation in a CM S
manual without reference to the factors enumerated in Barnhart. Estate
of Landers v. Leavitt, 545 F.3d 98, 106 (2d Cir. 2008). The court there did
not apply Chevron, but even without considering the Barnhart factors or
any similarity to the context of the interpretation in Barnhart, it
recognized that where “CM S, a highly expert agency, administers a large
complex regulatory scheme in cooperation with many other institutional
actors, the various possible standards for deference— namely, Chevron
and Skidmore— begin to converge.” Id. at 107 (quotation and alteration
omitted).
24                 FOURNIER V . SEBELIUS

Barnhart, 535 U.S. at 220 (citing Commodity Futures
Trading Comm’n v. Schor, 478 U.S. 833, 845–46 (1986)).

    Appellants contend that the legislative history of
§ 1395y(a)(12) contradicts the dental exclusion’s plain
language and makes the Secretary’s interpretation
unreasonable.       The Senate Report accompanying the
Medicare Act expressed the desire to provide coverage for
“complex surgical procedures.” See S. Rep. No. 89-404, at
49. House and Senate reports describe the excluded coverage
as “routine” dental care, which Appellants believe does not
include their “extensive, medically related procedures.” See,
e.g., id. When a statute is plain on its face, “we ordinarily do
not look to legislative history as a guide to its meaning.”
Tennessee Valley Auth. v. Hill, 437 U.S. 153, 184 n.29
(1978). Because we have concluded that the statutory dental
exclusion is ambiguous, legislative history permissibly may
be considered. But we conclude that the legislative history
more amply supports the agency’s argument than that of the
Appellants. The second part of § 1395y(a)(12) gives
coverage under Part A for inpatient dental services when a
patient requires hospitalization because of the severity of the
required procedure. An exception for inpatient services is
perhaps not the only way to provide for coverage for dental
work that is part of a complex surgical procedure and non-
routine care, but it is the one that Congress chose. The statute
does not compel the Secretary to cover dental work that is
related to complex procedures under Part B. The text of
§ 1395y(a)(12) does not indicate that there need be further
exceptions beyond those for inpatient care and the same-
physician rule.         We conclude that the Secretary’s
interpretation is reasonable and therefore permissible.
                   FOURNIER V . SEBELIUS                     25

                               V

    Appellants contend that the Secretary’s coverage rules for
dental services create irrational classifications and violate
their right to equal protection under the Fifth Amendment.
The “promise that no person shall be denied the equal
protection of the laws must coexist with the practical
necessity that most legislation classifies for one purpose or
another, with resulting disadvantage to various groups or
persons.” Romer v. Evans, 517 U.S. 620, 631 (1996). Equal
protection “does not forbid classifications.” Nordlinger v.
Hahn, 505 U.S. 1, 10 (1992). “It simply keeps governmental
decisionmakers from treating differently persons who are in
all relevant respects alike.” Romer, 517 U.S. at 631.
Appellants concede that the classification they challenge is
subject to the rational basis test, under which we will uphold
a classificatory scheme if it “bears a rational relation to some
legitimate end.” Id. Under this standard, Appellants “‘have
the burden to negat[e] every conceivable basis which might
support it.’” Diaz v. Brewer, 676 F.3d 823, 826 (9th Cir.
2012) (quoting FCC v. Beach Commc'ns, Inc., 508 U.S. 307,
315 (1993)).

    Appellants assert that the “favored classes” of (1) patients
who receive their dental services on the same day and from
the same physician who provided a covered service, (2)
patients who need extractions of teeth to prepare the jaw for
radiation treatment, and (3) patients who require a
comprehensive dental workup before a kidney transplant do
not collectively demonstrate any logical principle. But each
of these “favored classes” describes patients with
undoubtedly covered primary procedures who receive dental
treatment in connection with those covered procedures. By
contrast, Appellants’ primary procedures were noncovered
26                 FOURNIER V . SEBELIUS

dental treatments. Appellants concede that the goal of
limiting coverage is a legitimate governmental objective, and
the distinction here is rationally related to that goal.
Moreover, because their dental treatments were not ancillary
to a covered procedure, Appellants are not similarly situated
to the “favored classes” they cite. “Evidence of different
treatment of unlike groups does not support an equal
protection claim,” Wright, 665 F.3d at 1140 (quoting
Thornton v. City of St. Helens, 425 F.3d 1158, 1168 (9th Cir.
2005)). We conclude that there is no violation of the
Constitution’s guarantee of equal protection.

                              VI

    Appellants’ illnesses, Sjogren’s Syndrome and graft-
versus-host disease, are serious, and the conditions that these
diseases present strongly require dental treatment to maintain
a patient’s health against catastrophic health risks. The
claims of Appellants are sympathetic, and their desire for
coverage is understandable. But not all medically necessary
services are covered by Medicare, and the Secretary has
implemented a coverage framework consistent with the goals
of Congress that there be broad denial of coverage for dental
services. Although we have concluded that the statutory
provision for exclusion of dental services is ambiguous in the
sense that plausible divergent constructions can be urged, we
also conclude that the Secretary’s interpretation of the statute
is reasonable. The underlying conditions of Sjogren’s
Syndrome and graft-versus-host disease are complex, but the
consequent need is for dental services that are routine in the
sense that they are not different from services commonly
given others, that is, preparation and application of crowns,
bridgework, and fillings. In light of this comprehensive and
specific legislative command, which broadly excludes
                  FOURNIER V . SEBELIUS                  27

primary dental services from Medicare coverage, we have
concluded both that the Secretary’s statutory interpretation
warrants Chevron deference, and that the Secretary’s
statutory interpretation is reasonable.

   AFFIRMED.
