 United States Court of Appeals
        FOR THE DISTRICT OF COLUMBIA CIRCUIT



Argued October 20, 2016         Decided November 29, 2016

                      No. 15-1156

      AMERICAN POSTAL WORKERS UNION, AFL-CIO,
                    PETITIONER

                           v.

            POSTAL REGULATORY COMMISSION,
                     RESPONDENT

             UNITED STATES POSTAL SERVICE,
                      INTERVENOR


            On Petition for Review of an Order
           of the Postal Regulatory Commission


    Michael T. Anderson argued the cause for petitioner.
With him on the brief were Lorrie E. Bradley and Jeremiah
Fugit.

     Jeffrey E. Sandberg, Attorney, U.S. Department of
Justice, argued the cause for respondent. With him on the
brief were Benjamin C. Mizer, Principal Deputy Assistant
Attorney General, Michael S. Raab, Attorney, David A.
Trissell, General Counsel, Postal Regulatory Commission,
and Christopher Laver, Deputy General Counsel.
                               2
   Before: WILKINS, Circuit Judge, and EDWARDS and
WILLIAMS, Senior Circuit Judges.

    Opinion for the Court filed by Circuit Judge WILKINS.

     WILKINS, Circuit Judge: The American Postal Workers
Union (the “Union”) petitions this Court for review of the
Postal Regulatory Commission’s (“PRC”) denial of its
December 13, 2013 amended complaint. In its amended
complaint, the Union alleged that the United States Postal
Service failed to comply with First-Class Mail service
standards. See Am. Compl. ¶ 20. Upon review, the PRC
dismissed the Union’s amended complaint for three reasons.
First, the PRC explained that the service standards set forth in
39 C.F.R. § 121.1 are service “expectations” and not service
“requirements.” U.S. Postal Regulatory Comm’n, Order No.
2512, Order Granting Motion for Reconsideration and
Granting Motion to Dismiss 9 (May 27, 2015) [hereinafter
PRC Order No. 2512]; see id. at 14. Second, the PRC ruled it
remedied the Postal Service’s noncompliance when it
instructed the Postal Service to improve service compliance in
the Annual Compliance Determination. Id. at 17-20. Third,
the PRC noted that the Union’s amended complaint failed to
raise new or material issues of fact or law. Id. at 13-17. For
the following reasons, we deny the Union’s petition.

                              I.

    In 2006, Congress enacted the Postal Accountability and
Enhancement Act (“PAEA”) to reform postal operations and
mitigate the U.S. Postal Service’s financial difficulties. See
Postal Accountability & Enhancement Act, Pub. L. No. 109-
435, 120 Stat. 3198 (2006). Congress concluded that the
Postal Service maintained more facilities than economically
necessary, and instructed the Postal Service to devise a
                               3
strategy for eliminating excess processing capacity. Id.
§ 302(c)(1)(B), 120 Stat. at 3219. As part of this mandate,
Congress created the PRC to ensure postal accountability and
oversee postal functions and facility reductions. See 39 U.S.C.
§ 501.

     The PAEA required the Postal Service to establish a set
of service standards for market-dominant products, including
First-Class Mail. Id. § 3691(a). These standards must be
devised in conjunction with the PRC, and serve as enforceable
benchmarks published in the Code of Federal Regulations.
Id.; see also U.S. Postal Regulatory Comm’n, Order No. 465,
Order Establishing Final Rules Concerning Periodic
Reporting of Service Performance Measurements and
Customer Satisfaction 5 (May 25, 2010). The service
standards are designed to achieve the general policy goals of
mail reliability and speed, and specify the amount of time
within which a customer may ordinarily expect his mail to be
delivered. 39 U.S.C. § 3691(b)(1). The Postal Service
promulgated its initial service standards in 2007, and has
revised those standards periodically. Id. § 3691(a).

     As relevant to this case, the Postal Service issued a final
rule on May 25, 2012, altering its existing service standards in
conjunction    with      the    Mail    Processing     Network
Rationalization (“MPNR”) initiative. The MPNR initiative
proposed closing more than 229 mail processing facilities in
two phases for a forecasted net savings of $2.1 billion. See
U.S. Postal Regulatory Comm’n, No. N2012-1, Advisory
Opinion on Mail Processing Network Rationalization
Changes 1, 28, 46 (Sept. 28, 2012) [hereinafter MPNR
Advisory Opinion]; see generally Revised Service Standards
for Market-Dominant Mail Products, 77 Fed. Reg. 31,190,
31,191-92 (May 25, 2012). During Phase 1, which was
scheduled to last from July 1, 2012 through February 2013,
                                 4
the Postal Service proposed closing approximately 140 plants.
77 Fed. Reg. at 31,192; MPNR Advisory Opinion, supra, at
46. Phase 2, which would result in the closure of the
remaining plants, was scheduled to begin in February 2014.
77 Fed. Reg. at 31,192; MPNR Advisory Opinion, supra, at
46. The post-February 2014 service standards for First-Class
Mail are summarized as follows: 1

    •   Overnight Mail: An overnight service standard will
        be applied to intra-Sectional Center Facility (“SCF”)
        domestic Presort First Class Mail pieces properly
        accepted at the SCF before the day-zero Critical Entry
        Time (“CET”). 77 Fed. Reg. at 31,194. The overnight
        standard will no longer apply to mail sent by retail
        customers, regardless of location. Id.

    •   Two-Day Mail: A two-day service standard will be
        applied to all inter-SCF domestic First-Class Mail
        pieces that are properly accepted before the day-zero
        CET if the drive time between the origin Processing
        and Distribution Center or Facility and destination
        SCF is six hours or less. Id.

    •   Three-, Four-, and Five-Day Mail: The three-, four-,
        and five-day service standards remain unchanged. A
        three-day service standard will be applied to all
        domestic First-Class Mail pieces properly accepted

1
  The current service standards contained in 39 C.F.R. § 121.1
reference an effective date of January 2015. For purposes of this
appeal, we are concerned with the service standards in effect during
the MPNR initiative. An interim version of the service standards
applied during Phase 1 of the MPNR initiative (from July 1, 2012
through January 31, 2014), and a final version of the service
standards took effect on February 1, 2014. For simplicity, only the
final service standards are detailed in this opinion.
                              5
       before the day-zero CET if the overnight and two-day
       service standards do not apply and additional
       origin/destination criteria are satisfied. Id. at 31,194-
       95. A four-day service standard will apply to domestic
       First-Class Mail pieces properly accepted before the
       day-zero CET if the overnight, two-day, and three-day
       service standards do not apply and additional
       origin/destination criteria are satisfied. 39 C.F.R.
       § 121.1(d) (2014). A five-day service standard will
       apply to “all remaining domestic First-Class Mail
       pieces properly accepted before the day-zero CET.”
       Id. § 121.1(e).

    These new service standards shifted a substantial portion
of mail previously subject to the overnight standard to either
the two-, three-, four-, or five-day service standards, and
further transferred a large volume of the two-day mail to the
three-, four-, and five-day service standards. PRC Order No.
2512, supra, at 18; MPNR Advisory Opinion, supra, at 7;
U.S. Postal Regulatory Comm’n, Annual Compliance
Determination Report Fiscal Year 2013 105 (Mar. 27, 2014)
[hereinafter ACD FY 2013].

     The PAEA further directs the Postal Service to develop a
“plan” for meeting its service standards, including the
establishment of “performance goals” for mail delivery.
PAEA § 302(a), (b)(1), 120 Stat. at 3219; see also U.S. Postal
Serv., Postal Accountability and Enhancement Act § 302
Network        Plan    (June      2008),      available     at
https://about.usps.com/postal-act-2006/postal-service-
networkplan.pdf [hereinafter Network Plan]. In accordance
with this directive, the Postal Service created a set of
“performance targets” to track its success in meeting its
service standards. See Network Plan, supra, at 7. For fiscal
year 2013, the target on-time delivery rates were 96.7%,
                               6
95.1%, and 95.0% for mail subject to overnight, two-day, and
three- to five-day service standards, respectively. U.S. Postal
Regulatory Comm’n, Annual Compliance Determination
Report Fiscal Year 2014 96 tbl. V-4 (Mar. 27, 2015)
[hereinafter ACD FY 2014]. The targets increased for fiscal
year 2014 to 96.8%, 96.5%, and 95.25% for mail subject to
overnight, two-day, and three- to five-day service standards,
respectively. Id.

     To evaluate the Postal Service’s compliance with its
service standards, the PRC must issue an Annual Compliance
Determination (“ACD”) report for each fiscal year. See 39
U.S.C. § 3653(b). If the PRC finds noncompliance, it must
take appropriate action to remedy the noncompliance. Id.
§ 3653(c). During Phase 1 of the MPNR initiative, the PRC
concluded that First-Class Mail presorted letters and postcards
met or exceeded all annual service performance targets for
fiscal year 2013. ACD FY 2013, supra, at 99, 105.
Comparably, First-Class Mail single-piece letters and
postcards met or exceeded service performance goals for the
overnight and two-day service targets, but did not reach the
service performance targets for the three- to five-day mail
category. Id. at 105. First-Class Mail flats and parcels,
however, underperformed and failed to reach any of their on-
time delivery performance goals for the third year in a row.
Id. at 99, 104, 106-07.

     The ACD results for fiscal year 2014 showed a continual
decline in Postal Service performance. While First-Class Mail
presorted letters and postcards subject to overnight or two-day
service standards continued to meet their applicable service
goals, all remaining First-Class Mail products failed to satisfy
their service requirements, including: (1) single-piece letters
and postcards subject to overnight, two-day, and three- to
five-day delivery; (2) pre-sorted letters and postcards subject
                              7
to three- and five-day delivery; (3) flats; (4) parcels; (5)
inbound letter post; and (6) outbound single-piece
international letters. ACD FY 2014, supra, at 87-88 tbls. V-1,
V-2. Although the decreased service performance occurred
during Phase 2 of the MPNR initiative, the Postal Service
linked its noncompliance to severe winter storms that plagued
the first and second quarters of fiscal year 2014. Id. at 88.
After reviewing the data, the PRC concluded that winter
storms likely impacted service delivery times, but nonetheless
cautioned that “weather cannot consistently be employed as a
catchall excuse for failing to meet performance standards.” Id.
at 104. The PRC further instructed that it “expects service
performance to improve in FY 2015.” Id. Regarding First-
Class Mail flats specifically, the PRC directed the Postal
Service to “improve service for First-Class Mail Flats in FY
2015 or to provide an explanation in the FY 2015 [Annual
Compliance Report] for why efforts to improve service
performance results . . . have been ineffective and detail what
changes it plans to make to improve service performance.” Id.

     Notwithstanding the PRC’s responsibility to publish
ACD reports, any interested person who believes the Postal
Service is not operating in compliance with its regulatory or
statutory requirements may file a complaint with the PRC. 39
U.S.C. § 3662(a). Within 90 days after receiving a complaint,
the PRC must either issue an order dismissing the complaint,
id. § 3662(b)(1)(A)(ii), or begin proceedings on any
complaint that “raises material issues of fact or law,” id.
§ 3662(b)(1)(A)(i). If the PRC finds a complaint to be
justified after discovery and appropriate hearings, it shall
order the Postal Service to “take such action as the
Commission considers appropriate in order to achieve
compliance with the applicable requirements and to remedy
the effects of any noncompliance.” Id. § 3662(c). In cases of
deliberate noncompliance by the Postal Service, the PRC may
                             8
additionally require the Postal Service to pay a fine. Id.
§ 3662(d).

     Given the dual remedies available through the ACD and
complaint process, the Newspaper Association of America
expressed concern several years ago that a finding of
compliance or noncompliance in an ACD could moot a
pending complaint on the same issue. U.S. Postal Regulatory
Comm’n, Order No. 195, Order Establishing Rules for
Complaints and Rate or Service Inquiries 21 (Mar. 24, 2009)
[hereinafter Rules for Complaints]. The PRC responded by
noting that Congress contemplated this exact issue and
addressed it in the statute. Id. at 22. Specifically, section
3653(e) creates a rebuttable presumption of compliance by the
Postal Service if the PRC issues a timely written
determination of compliance in an ACD. 39 U.S.C. § 3653(e);
see Rules for Complaints, supra, at 22-23. If Congress had
wished for an ACD to render a complaint moot, it would have
created a non-rebuttable presumption in section 3653(e).
Rules for Complaints, supra, at 23. The dual enforcement
scheme of ACD reports and complaints is necessary because
ACD proceedings are completed in short, fixed timeframes
and are not subject to the same opportunities for contesting
evidence in adversarial proceedings. Id. Thus, “Commission
findings in an annual compliance determination are relevant
to a pending complaint proceeding, but are not necessarily
dispositive of those issues.” Id.

                            II.

    On September 5, 2013, the Union submitted a complaint
to the PRC alleging that the Postal Service violated the
requirements of 39 U.S.C. §§ 3661 and 3691. See generally
Compl. ¶¶ 6-8, 21, 28. The Union amended its complaint on
December 13, 2013. See generally Am. Compl. In particular,
                               9
the Union alleged that the Postal Service regularly failed to
comply with its First-Class Mail service standards. Id. ¶ 20.
This failure to comply with service standards was allegedly
the direct result of the Postal Service’s MPNR initiative. Id.
¶ 21. As a result, the Postal Service violated service standards
on a nationwide basis and deprived individuals and business
mailers of the service to which they are entitled under law.
See id. ¶¶ 25-97. To support this theory, the Union provided a
list of representative locations affected by the MPNR
initiative where service standards were consistently violated.
See id. ¶¶ 25-77. The Union further conducted a test mailing
of forty letters from its office in Washington, D.C. to various
Union members across the country. Id. ¶¶ 78-91. Twenty-five
percent of these letters were not delivered in accordance with
the service standards set forth in 39 C.F.R. § 121.1. Id. ¶ 79.

     Upon review, the PRC initially dismissed the Union’s
amended complaint for lack of standing on February 27,
2014. See U.S. Postal Regulatory Comm’n, Order No. 2000,
Order Dismissing Complaint (Feb. 27, 2014). Subsequently,
on May 27, 2015, the PRC granted the Union’s motion for
reconsideration and vacated its earlier dismissal. See PRC
Order No. 2512, supra, at 1, 5-8. Nonetheless, the PRC again
dismissed the amended complaint, this time on the merits.
Splitting 2-1, the PRC offered three primary bases for its
decision. First, the PRC explained that the service standards
set forth in 39 C.F.R. § 121.1 are service “expectations” not
service “requirements.” Id. at 9. While service standards play
an important role in postal regulation, they “do not act as legal
requirements” unless measured by reference to external
performance goals. Id. at 10. Service standards themselves
provide no guarantee of actual service, but rather only offer a
description of expected mail delivery time. Id. Therefore, “the
premise that a complaint lies based on failing to provide
service in conformance with an expectation is misplaced.” Id.
                               10
     Second, the PRC noted that the Union’s complaint failed
to raise new or material issues of fact or law. Id. at 13. While
the Union performed a limited mailing test to support its
allegations, its results did not add any new information that
was not already publicly known or addressed by the PRC. Id.
at 16-17. The PRC was aware of the Postal Service’s
noncompliance with service standards and should not be
required to expend limited resources reestablishing a known
fact. See id. at 17; see also id. at 19-20 (“[A]fter an issue has
been considered under [either an ACD or a complaint], in
most instances reconsidering the same issue using the
alternative approach is not a necessary or efficient use of
resources.”). Unlike the situation contemplated by Congress
in which the PRC’s finding of compliance serves only as a
rebuttable presumption, the Union presented allegations
entirely consistent with the PRC’s findings. Id. at 20. Such
consistency does not present a new issue of material fact.

     Finally, the PRC noted that it already directed the Postal
Service to take remedial action to ensure future compliance.
Id. at 17. Given the unusual impact caused by winter storms,
the PRC determined that the appropriate action was to
“reiterate the Postal Service’s responsibility to meet service
performance goals.” Id. at 19. Because the PRC may direct
the same remedies for a finding of noncompliance under
either an ACD or a complaint, the PRC ruled it is unlikely to
award further relief for this instance of noncompliance. See
id. at 19-20. Thus, the PRC dismissed the Union’s amended
complaint.

    Commissioner Goldway, however, dissented from the
majority opinion and argued that the Union’s amended
complaint was prematurely dismissed. See U.S. Postal
Regulatory Comm’n, Order No. 2512, Dissenting Opinion of
Commissioner Goldway 1-3 (May 27, 2015). The dissent
                              11
argued that the PRC previously observed that full effect
would not be given to the statutory scheme if complaints
could be rendered moot by issuance of an ACD report. Id. at
2. Accordingly, the Union should be afforded the opportunity
to prove its case, and the majority’s dismissal denies the
Union a fair opportunity to engage in discovery and create a
full record. Id. at 3. Because the PAEA “anticipate[d] a robust
Complaint mechanism,” Commissioner Goldway argued, the
PRC’s remedial authority is much broader than the majority
described. Id. The PAEA intended for the ACD and complaint
processes to work in tandem, not in a manner that is mutually
exclusive. Id. Thus, the mere fact that the PRC has previously
recognized service quality problems in its ACD reports should
not bar a legitimate complaint. Id. at 1. The Union timely filed
a petition for review in this Court on May 29, 2015.

                              III.

     This case presents two primary questions. First, did the
PRC reasonably determine that the Postal Service’s
compliance with regulatory standards is evaluated by
reference to separately published service performance goals?
We answer this question in the affirmative. Second, did the
PRC act arbitrarily or capriciously by dismissing the Union’s
amended complaint for failure to raise a material issue of fact
or law? We answer this question in the negative.

                              A.

     This Court has jurisdiction to review the PRC’s dismissal
of a complaint pursuant to 39 U.S.C. § 3663. According to
section 3663, any person adversely affected by a final order of
the PRC may institute proceedings for judicial review of that
order. 39 U.S.C. § 3663. The Court “shall review the order or
decision in accordance with section 706 of title 5” based on
the record before the PRC. Id. Section 706 of the
                              12
Administrative Procedure Act permits the Court to set aside
agency action, findings, and conclusions if they are “arbitrary,
capricious, an abuse of discretion, or otherwise not in
accordance with law.” 5 U.S.C. § 706(2)(A); see GameFly,
Inc. v. Postal Regulatory Comm’n, 704 F.3d 145, 148 (D.C.
Cir. 2013). The scope of review under the arbitrary and
capricious standard “is narrow” and the Court “is not to
substitute its judgment for that of the agency.” Motor Vehicle
Mfrs. Ass’n of U.S. Inc. v. State Farm Mut. Auto. Ins. Co., 463
U.S. 29, 43 (1983). That said, the Court must be satisfied that
the agency examined all relevant data and articulated a logical
explanation for its decision, including a rational connection
between the facts and ultimate outcome. Id. An agency rule
may be considered arbitrary and capricious if the agency
relied on factors which Congress did not intend it to consider
or “offered an explanation for its decision that runs counter to
the evidence before the agency.” Id.

     With regards to statutory interpretation, the Court follows
the framework set forth in Chevron U.S.A. Inc. v. Natural
Resources Defense Council, 467 U.S. 837, 842-44 (1984). See
U.S. Postal Serv. v. Postal Regulatory Comm’n, 640 F.3d
1263, 1266 (D.C. Cir. 2011) (noting that because Congress
expressly delegated to the PRC responsibility to implement
the PAEA, the PRC’s interpretation is reviewable under
Chevron). Chevron review involves a two-step analysis. First,
if a statute is clear, the Court must give effect to Congress’s
unambiguous intent. Chevron, 467 U.S. at 842-43. Where
ambiguity plagues a statute, the Court must turn to the second
Chevron principle and give deference to the agency’s
reasonable interpretation of the statute. Id. at 843.
                             13
                             B.

     The first issue we address is the PRC’s interpretation of
“service standards.” The Union argues that the PRC
erroneously interprets service standards as aspirational goals
that lack the force of law. See Pet’r Br. 23-32. According to
the Union, the PRC has conflated service standards with
operational performance goals and implicitly authorized the
Postal Service to underperform. See id. at 30-35. The Union,
however, misconstrues the PRC’s order. The PRC does not
contend that service standards are legally unenforceable.
Resp’t Br. 33; see generally PRC Order No. 2512, supra, at 8-
12 (highlighting that service standards are enforceable when
assessed in conjunction with performance goals). Rather, the
PRC maintains that whether the Postal Service has complied
with its statutory requirements is evaluated by separately
published service performance goals. Resp’t Br. 33; see PRC
Order No. 2512, supra, at 8-12 (explaining the interaction
between service standards and performance goals). The PRC
acknowledges that the service standards contained in 39
C.F.R. § 121.1 possess legal force. Resp’t Br. 34. Thus, the
issue before this Court is not whether service standards are
legally enforceable – all parties agree they are – but whether
the PRC’s method for evaluating when those service
standards have been violated (i.e., by examining external
performance goals) is reasonable. We find that it is.

    First, Congress has not directly addressed the issue of
how Postal Service noncompliance should be calculated.
Pursuant to the PAEA, the Postal Service must promulgate
regulations that establish service standards for market-
dominant products. 39 U.S.C. § 3691(a). In addition, the
Postal Service is tasked with developing a plan for complying
with service standards, which includes establishing
“performance goals.” PAEA § 302(a), (b)(1), 120 Stat. at
                              14
3219. The PAEA does not, however, contain any governing
principle by which to distinguish compliance from
noncompliance. Rather, by its silence, the PAEA commits to
the PRC’s discretion the development of legal benchmarks
necessary for determining whether the Postal Service violated
its service standards. Thus, given congressional silence on this
issue, we proceed to Chevron step two.

     Second, we find the PRC’s interpretation that “service
standards” should be measured in conjunction with separately
defined performance goals reasonable and entitled to
deference. The PAEA requires the Postal Service to establish
a set of service standards, not service guarantees. See 39
U.S.C. § 3691(a). These standards must be designed to
“reasonably assure Postal Service customers delivery
reliability, speed and frequency.” Id. § 3691(b)(1)(C). Such
“reasonabl[e] assur[ance]” simply creates an “expectation” of
on-time delivery without developing an enforceable right to
sue over each-and-every piece of mail that arrives outside that
delivery window. Therefore, when examining whether the
Postal Service has complied with its service obligations, the
PRC regularly analyzes the Postal Service’s rate of on-time
delivery performance in reference to separately published
service performance goals.

    This interpretation is reasonable given that nothing in the
PAEA suggests that the Postal Service violates the law every
time a piece of mail arrives outside the applicable time
window set forth in 39 C.F.R. § 121.1. A small amount of
mail will always fail to be delivered within its specified
service standard. See Modern Service Standards for Market-
Dominant Products, 72 Fed. Reg. 72,216, 72,220 (Dec. 19,
2007). This reality is the result of unpredictable weather
conditions, high mail volume, unanticipated labor disputes,
human error, and other workplace or regional events. The
                               15
PRC is aware of the logistical impossibility of ensuring timely
delivery of each piece of mail and, therefore, determined that
Postal Service compliance must be analyzed with reference to
an external target. The Union’s contentions to the contrary
would subject the Postal Service to a flood of litigation each
time a birthday card or letter was delivered late. Given the
financial woes already plaguing the Postal Service, we cannot
conclude that Congress intended such a result.

     Further, if service standards could be violated on an
envelope-by-envelope basis, it would be a foregone
conclusion in every ACD that the Postal Service is in
noncompliance with the statute. This result would eliminate
any meaningful distinction between compliance and
noncompliance. Rather than being subject to remedial
directives only in years of noncompliance, the Postal Service
would be forced to undertake remedial measures yearly. See
39 U.S.C. § 3653(c) (“If, for a year, a timely written
determination of noncompliance is made under subsection (b),
the Postal Regulatory Commission shall take appropriate
action . . . .”). This contravenes the statutory structure, which
clearly contemplates that the Postal Service can be found in
compliance with its service standards. See, e.g., id. § 3653(b)
(“If, with respect to a year, no instance of noncompliance is
found under this subsection to have occurred in such year, the
written determination shall be to that effect.”). A contrary
result would frustrate congressional intent.

     Similarly, nothing in the PAEA requires the Postal
Service to disclose information to the PRC regarding the
delivery outcome of every single piece of mail. The PAEA
only mandates that the Postal Service provide the PRC with a
report analyzing the “quality of service” in enough detail “to
demonstrate that all products during such year complied with
all applicable requirements” in Title 39. Id. § 3652(a)(1). The
                              16
information provided by the Postal Service must describe the
level of service (i.e., speed of delivery and reliability)
provided, but need not identify whether each individual item
of mail achieved its on-time service performance standard.
This supports the PRC’s determination that compliance
evaluations should occur in the aggregate.

     Finally, the legislative history bolsters the PRC’s
interpretation. In 2004, Congress considered a legislative
proposal in which the language corresponding to section
3691(b)(1)(C) would have required service standards to
“guarantee Postal Service customers delivery reliability,
speed and frequency consistent with reasonable rates and best
business practices.” S. 2468, 108th Cong. § 301 (2004)
(emphasis added). A later version of the legislation, which
was enacted, replaced the word “guarantee” with the phrase
“reasonably assure,” S. 662, 109th Cong. § 301 (2005), thus
clarifying that service standards do not create binding on-time
delivery requirements for each piece of mail. See 39 U.S.C.
§ 3691(b)(1)(C); Chickasaw Nation v. United States, 534 U.S.
84, 93 (2001) (“We ordinarily will not assume that Congress
intended ‘to enact statutory language that it has earlier
discarded in favor of other language.’” (quoting INS v.
Cardoza-Fonseca, 480 U.S. 421, 443 (1987))). In light of
these factors, we hold that the PRC’s interpretation of service
standards is reasonable and entitled to deference.

                              C.

     The second question we must answer is whether the PRC
acted arbitrarily or capriciously by dismissing the Union’s
amended complaint. As a preliminary matter, we find that the
PRC reasonably construed the Union’s amended complaint as
alleging that the Postal Service’s aggregate rate of compliance
fell below its established goals. See PRC Order No. 2512,
                              17
supra, at 13. As previously discussed, a complaint alleging
violations of service standards on an envelope-by-envelope
basis does not state a cognizable claim. Rather, service
standards may only be violated in the aggregate when
measured against external performance goals. Thus, PRC’s
construction of the Union’s amended complaint conforms
with its interpretation of service standards discussed in
Section III.B. For the reasons discussed below, we hold that
the PRC’s decision to dismiss the Union’s amended complaint
was not arbitrary or capricious.

     The strongest support for upholding the PRC’s dismissal
is the fact that the PRC already recognized the Postal
Service’s failure to consistently meet its service standards,
and instructed the Postal Service to take remedial action on
this front. See id. at 13, 17, 19-20. Section 3662 allows any
interested person who believes that the Postal Service is not
operating in compliance with its service obligations to file a
complaint. 39 U.S.C. § 3662(a). The PRC, however, may
dismiss any complaint that does not raise “material issues of
fact or law.” Id. § 3662(b)(1)(A). While this phrase is not
statutorily defined, it is not unreasonable to require the issue
of fact or law to be one that the PRC has not already
addressed. Black’s Law Dictionary defines “material” as
being “[o]f such a nature that knowledge of the item would
affect a person’s decision-making; significant; essential.”
Material, BLACK’S LAW DICTIONARY (10th ed. 2014). In this
case, the PRC was already aware of the Postal Service’s
noncompliance with service standards, and acknowledged that
this noncompliance was likely attributable to severe and
uncharacteristic winter weather. ACD FY 2014, supra, at 88,
104. Nonetheless, the PRC instructed the Postal Service to
take appropriate remedial action to ensure service compliance
in fiscal year 2015. See id. at 104. In dismissing the Union’s
amended complaint, the PRC concluded that none of the
                              18
allegations brought any new facts to the PRC’s attention that
would cause it to modify the relief previously imposed. See
PRC Order No. 2512, supra, at 13, 16-20. Because the PRC
already addressed the Postal Service’s noncompliance, there
was nothing “material” about the Union’s allegations.

     In essence, the Union’s amended complaint requested
that the PRC issue a different remedial order that required the
Postal Service “to cease and desist from making changes in its
mail processing network that will cause it to violate service
standards.” Am. Compl. at 22. By articulating an alternative
rationale for the Postal Service’s noncompliance, the Union
contends that the PRC’s remedial order was ineffective to
redress violations of service standards caused by post office
closures. The Union, however, did not challenge the adequacy
of the PRC’s remedy before this Court and, accordingly, has
forfeited this claim. See Nat’l Oilseed Processors Ass’n v.
OSHA, 769 F.3d 1173, 1182 (D.C. Cir. 2014) (holding that
petitioners forfeited a claim by mentioning it “only in a
cursory manner”); Pet’r Br. 45 (arguing that if the PRC’s
statements urging the Postal Service to improve “were
enforceable through agency order and court injunction, they
might satisfy the Commission’s duty”).

     Finally, the Union argues that the PRC cannot rely on its
finding of noncompliance in the ACD to avoid processing a
meritorious complaint on the same or similar issues. Pet’r Br.
36, 41-42. The PRC addressed a comparable concern in its
March 24, 2009 Order Establishing Rules for Complaints and
Rate or Service Inquiries. Specifically, the PRC agreed that
“it would not give full effect to the statutory scheme if
complaints could be rendered moot by the issuance of an
annual compliance determination.” Rules for Complaints,
supra, at 22. The PRC does not take a contrary position in the
present case. Nothing in the PRC’s order states that an
                             19
individual is estopped from contesting findings in the ACD
report by objecting or filing a complaint. The right to object
remains intact. As shown above, the PRC’s denial of the
Union’s amended complaint in this case was based on the fact
that the complaint failed to raise a material issue of fact or
law. Thus, the Union’s argument on this ground is
unpersuasive.

    Accordingly, we hold that the PRC’s dismissal of the
Union’s amended complaint was not arbitrary or capricious.

                             ***

     For the reasons discussed above, we deny the Union’s
petition. The PRC reasonably determined that whether service
standards are violated must be evaluated in reference to
external performance goals. Based on this interpretation, the
PRC logically construed the Union’s amended complaint as
asserting a claim for violation of service standards in the
aggregate, in accordance with the relevant performance goals.
The PRC’s subsequent dismissal of this amended complaint
was not arbitrary or capricious because the amended
complaint failed to allege new issues of material fact or law.
Accordingly, the petition is denied.

                                                  So ordered.
