United States Court of Appeals

FOR THE DISTRICT OF COLUMBIA CIRCUIT

Argued May 10, 2019 Decided September 13, 2019

No. 18-1328

DOUGLAS F. CARLSON,

PETITIONER

v.

POSTAL REGULATORY COMMISSION,

RESPONDENT

PITNEY BOWES INC. AND UNITED STATES POSTAL SERVICE,

INTERVENORS

On Petition for Review of an Order

of the Postal Regulatory Commission

Douglas F. Carlson, Pro se, argued the cause and filed the 

briefs for petitioner.

Joshua M. Salzman, Attorney, U.S. Department of Justice, 

argued the cause for respondent. With him on the brief were 

Michael S. Raab, Attorney, David A. Trissell, General Counsel, 

Postal Regulatory Commission, Anne J. Siarnacki, Deputy 

General Counsel, and Laura E. Zuber, Attorney.

Before: MILLETT, KATSAS, and RAO, Circuit Judges.
2

Opinion for the Court filed by Circuit Judge RAO.

RAO, Circuit Judge: Wedding invitations, birthday cards 

from grandma, and electricity bills all travel through the United 

States Postal Service with a simple first-class stamp. Perhaps 

unnoticed by many who use the “Forever Stamp,” in January 

2019, the Postal Service raised the price of this stamp by five 

cents, a ten-percent increase. Douglas Carlson’s pro se petition 

challenges this stamp price hike, which is part of Postal 

Regulatory Commission Order 4875,

1 as inconsistent with the 

Administrative Procedure Act (APA).

We agree with Carlson that the stamp price hike did not

meet the APA’s requirements for reasoned decisionmaking.

The Commission failed to provide an adequate explanation of 

the increase and, relatedly, failed to respond to public 

comments challenging the increase under relevant statutory 

factors and objectives included in the Commission’s organic 

statute, the Postal Accountability and Enhancement Act 

(PAEA). Accordingly, we grant the petition for review and 

vacate the part of Order 4875 addressing rate adjustments for 

the category of first-class mail. Because the category of firstclass rates is severable, we leave the remainder of the Order

intact.

I.

We begin with the statutory requirements governing the 

Commission. In enacting the PAEA, Congress moved from an 

adjudicatory model of postal rate review to a regulatory one. 

“[A]dministrative procedures are divided into two categories,” 

adjudication and rulemaking, with the latter defined as 

“prospective decisions of general applicability focusing on 

1 Postal Regulatory Comm’n, Order No. 4875, Dkt. R2019-1 (Nov. 

13, 2018), J.A. 186.
3

policy.” 2 Charles H. Koch, Jr. & Richard Murphy, 

Administrative Law & Practice § 5:1 (3d ed. 2019). Regulation 

“is primarily concerned with policy considerations” while 

“adjudication is concerned with the determination of past and 

present rights and liabilities.” Bowen v. Georgetown Univ. 

Hosp., 488 U.S. 204, 219 (1988) (Scalia, J., concurring) 

(quoting Attorney General’s Manual on the Administrative 

Procedure Act 14 (1947) (“AG Manual”)).

Before the PAEA, adjudication of postage rates was a 

lengthy process that delayed rate changes by as much as 

eighteen months. S. Rep. No. 108-318, at 3–4 (2004). The 

PAEA reconstituted the Postal Rate Commission as the Postal 

Regulatory Commission, an agency headed by five 

commissioners appointed by the President and removable only 

for stated causes.

2 See 39 U.S.C. §§ 501–02. The PAEA

strengthened the role of the Commission by repealing the 

Postal Service’s authority to modify rates without the 

2 From 1789 to 1970, the Post Office Department administered 

the Nation’s mails. See Act of Sept. 22, 1789, ch. 16, 1 Stat. 70. 

Between 1970 and the enactment of the PAEA in 2006, Congress 

abolished the Post Office Department and divided ratemaking 

authority between the Postal Service and the Postal Rate 

Commission, two distinct agencies. See Postal Reorganization Act of 

1970, 84 Stat. 719; see also Nat’l Ass’n of Greeting Card Publishers 

v. U.S. Postal Serv., 462 U.S. 810, 813, 821 (1983). Under the prior 

Act, the Postal Service initiated rate changes by submitting requests 

to the Postal Rate Commission with “such suggestions for rate 

adjustments as it deem[ed] suitable.” 39 U.S.C. § 3622(a) (2000). 

The Postal Rate Commission then conducted a hearing on the record 

and determined what rate to recommend to the Postal Service, taking 

into account nine statutory factors. Id. §§ 3622(b), 3624(a). The 

Postal Service had authority to challenge the Commission’s rate 

recommendation and, in some circumstances, to reject the 

Commission’s recommendation and impose its own modifications. 

Id. § 3625.
4

Commission’s approval. See PAEA, Pub. L. No. 109-435, 

§ 201(b), 120 Stat. 3198, 3205 (2006) (repealing 39 

U.S.C. § 3625). The PAEA also abolished the requirement for

the Commission to hold a hearing on the record prior to 

adopting any rate change. Id. (repealing 39 U.S.C. § 3624).

Instead, Congress directed the Commission to establish “a 

modern system for regulating rates and classes for marketdominant products.” 39 U.S.C. § 3622(a).

Rather than adjudicate rates through fact-intensive

hearings, the PAEA requires the Commission to establish a 

regulatory system for rate approval and then evaluate and 

approve specific postal rates through rulemaking, subject to 

review under the standards of the APA. Id. §§ 3622, 3663.

Because “[t]he APA does not contemplate the use of 

adjudication to develop rules,” Ala. Power Co. v. FERC, 160 

F.3d 7, 11 n.5 (D.C. Cir. 1998), Congress’s decision to replace 

the Commission’s adjudicatory model with a regulatory model 

guided by APA standards is significant. See Bowen, 488 U.S.

at 218 (“The entire [APA] is based upon a dichotomy between 

rule making and adjudication.” (quoting AG Manual)).

The PAEA dictates that the Commission’s regulatory 

system “shall be designed” to achieve nine statutory objectives 

and “shall take into account” fourteen statutory factors. 39 

U.S.C. § 3622(b)–(c) (reproduced in Appendix, infra). The

Commission established the required “modern system for 

regulating rates” in November 2007. See generally Postal 

Regulatory Comm’n, Order No. 43, 72 Fed. Reg. 63,662 (Nov. 

9, 2007) (the “system regulation”). The part of the system 

regulation relevant to this case addresses rate adjustments of 

general applicability. See 39 C.F.R. pt. 3010, subpart B. Under 

the system regulation, the Postal Service initiates a proposed 

rate change by providing notice to the public and to the 

Commission. Id. § 3010.10(a). Such notice must be provided 
5

at least forty-five days prior to a rate change, and the Postal 

Service is encouraged to provide as much advance notice as 

practicable. Id. § 3010.10. The Postal Service’s notice must 

include, among other things, “[a] discussion that demonstrates 

how the planned rate adjustments are designed to help achieve 

the objectives listed in 39 U.S.C. § 3622(b) and properly take 

into account the factors listed in 39 U.S.C. § 3622(c).” Id.

§ 3010.12(b). The notice must also include any “other 

information” that would assist the Commission in issuing “a 

timely determination of whether the planned rate adjustments 

are consistent with applicable statutory policies.” Id.

§ 3010.12(b)(12). The Postal Service’s notice serves as the 

proposed rule before the Commission issues a final regulation, 

i.e., the rate approval order. 

After receiving notice from the Postal Service, the 

Commission establishes a docket allowing twenty days for 

public comment on the proposed change. Id. § 3010.11(a). 

Within fourteen days of the end of the comment period, the 

Commission must “issue an order announcing its findings.” Id.

§ 3010.11(d). The system regulation does not specify how the 

Commission must consider the PAEA’s objectives and factors; 

however, rate adjustments must be “consistent with applicable 

law.” Id. § 3010.11(e), (i). If the Commission finds that a 

proposed rate adjustment is inconsistent with applicable law, 

the Postal Service must amend its notice, include “sufficient 

explanatory information to show that all deficiencies identified 

by the Commission have been corrected,” and allow an 

additional seven-day period of public comment. Id.

§ 3010.11(f), (g). 

The Postal Service proposed the stamp price hike in 

October 2018 as part of a series of adjustments to the category 
6

of first-class postage rates.3 See U.S. Postal Serv., Notice of 

Market-Dominant Price Change, Dkt. No. R2019-1 (Oct. 10, 

2018), J.A. 1. Under the proposal, the rate for a one-ounce, 

stamped letter would increase from fifty cents to fifty-five 

cents. This ten percent increase required the Service to adjust 

other classes of first-class postage rates in order to stay within 

the overall statutory price increase cap of about 2.5 percent. See

39 U.S.C. § 3622(d)(1)(A). The proposal thus decreased the 

price of some first-class mail products and increased others by 

a smaller percentage. The stamp price hike, however, was 

remarkable—the largest absolute increase in the price of 

stamps since 1863.

4 As a percentage, it was the largest increase 

since 1995.5

The Postal Service justified the magnitude of the stamp 

price hike by asserting an interest in keeping the price of stamps 

“at round numbers divisible by five.” J.A. 8. According to the 

Postal Service, this approach helps to achieve “simplicity of 

structure”—one of the fourteen factors under the PAEA, see 39 

U.S.C. § 3622(c)(6)—by “facilitat[ing] convenience for retail 

customers” through “a straightforward, understandable pricing 

structure.” J.A. 8–9. The Postal Service sought to minimize 

concern about the size of the stamp price hike by asserting that

corresponding reductions in postage rates for first-class mail 

products with nonstandard weight or shape would mitigate the 

impact of the increased price of first-class letter stamps. 

Moreover, the Service stated its intent to keep stamp prices 

divisible by five in future years, suggesting that a large increase 

3 The first-class postage adjustments were part of a notice to 

adjust rates across several other categories of market-dominant 

products. Those other rates are not challenged here.

4 See U.S. Postal Serv., Rates for Domestic Letters Since 1863

(Feb. 2019), https://about.usps.com/who-we-are/postalhistory/domestic-letter-rates-since-1863.pdf (listing rates).

5 See id.
7

in the price of stamps in 2019 might postpone the need for 

another increase, “subject to the business conditions that obtain 

in coming years.” J.A. 9.

The Commission opened a docket to receive public 

comment for the required twenty days. See Postal Regulatory 

Comm’n, Order No. 4851, 83 Fed. Reg. 52,242 (Oct. 16, 2018). 

During this time, the Commission received thirty-four 

comments, including a comment from Carlson, a postal

customer and watchdog. See Carlson v. U.S. Postal Serv., 504 

F.3d 1123 (9th Cir. 2007).

Carlson raised a series of arguments against the stamp 

price hike, including that the Service failed to account for 

several statutory objectives and factors. First, Carlson argued

that keeping the price of a stamp divisible by five did not 

promote the value of “simplicity of structure” under 39 U.S.C. 

§ 3622(c)(6). J.A. 95–100. Second, he disputed the Postal 

Service’s evaluation of the stamp price hike’s likely impact and 

argued that the detrimental “effect of rate increases upon the 

general public” weighed against the Postal Service’s proposal 

under 39 U.S.C. § 3622(c)(3). J.A. 103–05. Third, he argued 

that raising the price of stamps by five cents was inconsistent 

with the statutory objective of “establish[ing] and 

maintain[ing] a just and reasonable schedule for rates” under 

39 U.S.C. § 3622(b)(8). J.A. 104. The Greeting Card 

Association similarly commented on flaws in the Postal 

Service’s simplicity-of-structure rationale and noted the need 

to consider other statutory factors. J.A. 111–16. The 

Association for Postal Commerce argued that increasing the 

price of stamps in five-cent increments could reduce 

“predictability and stability in rates,” contrary to the statutory 

objective under 39 U.S.C. § 3622(b)(2). J.A. 89.
8

After the close of the public comment period, the 

Commission issued Order 4875. The Order included a finding

that the overall first-class mail rate adjustments, including the 

stamp price hike, were “consistent with 39 U.S.C. §§ 3622(d) 

and 3622(e), and may take effect as planned.” J.A. 250. The 

Order referenced, but did not resolve, Carlson’s disagreement 

with the Postal Service’s simplicity-of-structure rationale. 

Instead, the Order encouraged the Postal Service “to 

collaborate with mailers . . . about pricing” in order to reassess 

the utility of keeping stamp prices divisible by five in the 

future. J.A. 209. Aside from “simplicity of structure,” the 

Commission did not cite any of the PAEA objectives and 

factors listed in subsections 3622(b) and (c), but instead 

evaluated the increase only for compliance with quantitative 

rate caps established by other provisions of the PAEA. The 

Commission determined that the Postal Service’s proposal 

complied with the rate cap and approved the rate increase, 

stating that “subject to certain limitations, most prominently 

the price cap, the PAEA gives the Postal Service pricing 

flexibility within First-Class Mail.” J.A. 208–09.

Carlson timely petitioned this Court for review of the firstclass rate adjustments in Order 4875, arguing that the stamp 

price hike violated the APA because the Commission failed to 

consider relevant statutory objectives and factors and failed to 

provide a reasoned explanation of the exercise of its authority 

under the system regulation. The PAEA grants this Court 

jurisdiction over orders or decisions of the Commission and 

incorporates the APA as the framework for review. 39 U.S.C. 

§ 3663; see also GameFly, Inc. v. Postal Regulatory Comm’n, 

704 F.3d 145, 148 (D.C. Cir. 2013). Because Carlson is 

proceeding pro se, we construe his filings liberally. See, e.g.,

United States v. Gooch, 842 F.3d 1274, 1278 (D.C. Cir. 2016).
9

II.

Carlson claims that the stamp price hike is arbitrary and 

capricious under the APA because the Commission failed to 

consider the objectives and factors listed in the PAEA. The 

Commission agrees that these statutory factors and objectives 

are relevant to rate review, but maintains that it has discretion 

to defer consideration of those provisions until after approving 

a rate change, especially given its interpretation that the PAEA 

requires the Commission to evaluate rate-change proposals 

quickly.

We conclude that the Commission’s consideration of this 

increase fell short of the APA’s requirements for reasoned 

decisionmaking because the Commission failed to provide an 

adequate explanation for the stamp price hike, and, relatedly, 

failed to respond to public comments challenging the stamp 

price hike under the PAEA’s statutory factors and objectives.

Moreover, the PAEA does not require the Commission to rush 

to decision. Based on the text and structure of the PAEA, we 

conclude that the PAEA requires consideration of all relevant 

statutory objectives and factors as part of the regulatory process 

and does not authorize the Commission to defer evaluation of 

those objectives and factors until after it approves a rate 

change. Finally, the system regulation requires the 

Commission to determine that proposed rate adjustments are

“consistent with applicable law,” 39 C.F.R. § 3010.11(e),

before issuing a rate approval order. At a minimum, this also 

required the Commission to comply with the APA and the 

PAEA by weighing the statutory factors and objectives before 

adopting the stamp price hike.

A.

The stamp price hike is part of Order 4875, which is a 

“rule” within the meaning of the APA because it is an 
10

“approval . . . for the future of rates.” See 5 U.S.C. § 551(4); 

see also Order No. 43, 72 Fed. Reg. at 63,666 (“The notice and 

comment guarantees of section 553 of the APA apply to . . . 

rate adjustments.”). When reviewing a rule under the APA, we 

will set aside an order that is “arbitrary, capricious, an abuse of 

discretion, or otherwise not in accordance with law” or that is 

“in excess of statutory jurisdiction, authority, or limitations, or 

short of statutory right.” 5 U.S.C. § 706(2)(A), (C). “The 

APA’s arbitrary-and-capricious standard requires that agency 

rules be reasonable and reasonably explained.” Nat’l Tel.

Coop. Ass’n v. FCC, 563 F.3d 536, 540 (D.C. Cir. 2009). An 

agency violates this standard if it “entirely fail[s] to consider 

an important aspect of the problem.” Motor Vehicle Mfrs. Ass’n 

v. State Farm Mut. Auto. Ins. Co., 463 U.S. 29, 43 (1983). An 

agency also violates this standard if it fails to respond to 

“significant points” and consider “all relevant factors” raised 

by the public comments. Home Box Office, Inc. v. FCC, 567 

F.2d 9, 35–36 (D.C. Cir. 1977).

Accordingly, an agency must respond to comments “that 

can be thought to challenge a fundamental premise” underlying 

the proposed agency decision. MCI WorldCom, Inc. v. FCC, 

209 F.3d 760, 765 (D.C. Cir. 2000). An agency need not 

“discuss every item of fact or opinion included in the 

submissions made to it.” Del. Dep’t of Nat. Res. & Envtl. 

Control v. EPA, 785 F.3d 1, 17 (D.C. Cir. 2015) (citation 

omitted). An agency’s response to public comments, however,

must be sufficient to enable the courts “to see what major issues 

of policy were ventilated . . . and why the agency reacted to 

them as it did.” Id. (citation omitted). Even when an agency 

“has significant discretion in deciding how much weight to 

accord each statutory factor,” that does not mean it is “free to 

ignore any individual factor entirely.” Tex. Oil & Gas Ass’n v. 

EPA, 161 F.3d 923, 934 (5th Cir. 1998) (citing Weyerhaeuser 

Co. v. Costle, 590 F.2d 1011, 1045 (D.C. Cir. 1978))
11

(evaluating agency’s consideration of statutory factors under 

arbitrary-and-capricious review).

The PAEA sets forth a framework of statutory objectives 

and factors for consideration in rate setting. While the statute 

does not specify how these objectives and factors must be 

accounted for in any particular rate order, the Commission 

must apply the relevant objectives and factors to individual rate 

adjustments. Our cases confirm this and provide some limited 

guidance. We have held that “[i]n reviewing [proposed] rates 

for market-dominant products, the Commission must consider 

the statutory factors set out in 39 U.S.C. § 3622(c).” Newspaper 

Ass’n of Am. v. Postal Regulatory Comm’n, 734 F.3d 1208, 

1210 (D.C. Cir. 2013). The factors listed in the PAEA 

“establish[] rate requirements for all market-dominant 

products.” Id.; see also U.S. Postal Serv. v. Postal Regulatory 

Comm’n, 676 F.3d 1105, 1107 (D.C. Cir. 2012) (for purposes 

of the Commission’s annual compliance determination, “the 

PAEA provides the Commission with fourteen factors to 

consider when reviewing Postal Service rates” in effect during 

the preceding year). 

Congress left the Commission leeway to establish, through 

regulation, a process for considering the PAEA’s objectives 

and factors. 39 U.S.C. § 3622(a)–(c). We recognize that not 

every statutory factor and objective will be relevant to an 

individual rate assessment and that the weight accorded 

particular factors may therefore vary in each case. But this does 

not mean the Commission may simply disregard the objectives 

and factors when approving rate adjustments. Pursuant to the 

APA, the Commission’s orders must be “reasonable and 

reasonably explained.” Nat’l Tel. Coop. Ass’n, 563 F.3d at 540. 

Indeed, the Commission has long recognized that the 

PAEA’s objectives and factors are relevant to the assessment 
12

of postage rates. See Order No. 43, 72 Fed. Reg. at 63,665 

(explaining that the system regulation requires the Postal 

Service to address statutory objectives and factors as part of “a 

broad range of relevant issues in any notice of rate 

adjustment”); Postal Regulatory Comm’n, Order No. 203, 74 

Fed. Reg. 20,834, 20,841 (May 5, 2009) (stating that Order 43 

implemented “a system of ratemaking to foster achievement of 

the requirements, objectives, and factors spelled out in” 39 

U.S.C. § 3622(b)–(c)). Similarly, in this case, the Commission 

acknowledges that lack of compliance with the objectives and 

factors can justify disapproval of a rate-change proposal and 

that the objectives and factors are relevant in the annual 

compliance review and adjudication of complaints. 

Moreover, consideration of the statutory factors is 

implicitly required by the Commission’s system regulation.

Under the system regulation, the Postal Service’s initial notice 

to the Commission of a proposed rate change must include “[a] 

discussion that demonstrates how the planned rate adjustments 

are designed to help achieve the objectives listed in 39 U.S.C. 

§ 3622(b) and properly take into account the factors listed in 

39 U.S.C. § 3622(c).” 39 C.F.R. § 3010.12(b)(7). More 

generally, the Postal Service must provide all information the 

Service believes “will assist the Commission to issue a timely 

determination of whether the planned rate adjustments are 

consistent with applicable statutory policies.” Id. 

§ 3010.12(b)(12).

The Commission must then determine whether the Postal 

Service’s planned rate adjustments are “consistent with 

applicable law,” id. § 3010.11(e), before the adjustments may 

take effect. If the Commission finds the rate adjustments are 

“inconsistent with applicable law,” the Postal Service must 

submit an amended notice explaining how it has modified the 

proposal to comply with relevant law. Id. § 3010.11(f). If an 
13

amended notice is still “found to be inconsistent with 

applicable law, the Commission shall explain the basis of its 

determination and suggest an appropriate remedy.” Id. 

§ 3010.11(j). 

The system regulation therefore makes clear that the 

Commission must exercise its rulemaking authority consistent 

with applicable law, which at a minimum includes the 

requirements of the PAEA and the APA. After receiving the 

Postal Service’s notice, the Commission must independently 

determine whether a proposed rate adjustment is “consistent 

with applicable law.” A proper application of the system 

regulation thus requires the Commission to consider the

statutory objectives and factors before issuing a rate adjustment

order. 

B.

The public comments about the stamp price hike 

highlighted several relevant statutory objectives and factors the 

Commission was required to consider under the APA. See 

Motor Vehicle Mfrs. Ass’n, 463 U.S. at 43; Home Box Office, 

567 F.2d at 35–36. Of course, the Commission should consider 

all relevant statutory factors when reviewing the Service’s rate 

adjustment notice, not only those factors raised in the public 

comments. The Commission, however, must also respond to 

significant points raised by the comments, especially when 

those comments challenge a fundamental premise underlying a 

rate increase. See MCI WorldCom, 209 F.3d at 765. When 

evaluating the Postal Service’s proposed stamp price hike, the 

Commission failed to address three categories of public 

comments that warranted response.

First, the Commission failed to address public comments 

that undermined the Postal Service’s interpretation of 

“simplicity of structure,” a PAEA factor. In its notice, the 
14

Postal Service claimed that keeping stamp prices divisible by 

five promotes “simplicity of structure” by “facilitat[ing] 

convenience” and making prices “straightforward” and 

“understandable.” J.A. 8–9. In response, the Greeting Card 

Association argued that no individual rate change could 

achieve “simplicity of structure” “for the entire schedule.” J.A. 

114. In his public comment, Carlson similarly argued that no 

individual postage rate constitutes a “structure.” J.A. 100–02. 

These comments refer to the text of the PAEA, which requires 

a particular type of simplicity: “simplicity of structure for the 

entire schedule and simple, identifiable relationships between 

the rates or fees charged the various classes of mail for postal 

services.” 39 U.S.C. § 3622(c)(6). By its plain terms, the statute 

refers to the simplicity of the pricing schedule as a whole and 

the relationships between different rates charged for different 

classes of postal services. It is not a provision about simple 

consumer prices, as suggested by the Postal Service. 

Carlson also challenged the Postal Service’s claim of 

convenience, noting that most transactions would not involve 

the supposed inconvenience of counting pennies because most 

customers pay by debit or credit card and buy stamps in 

multiples of five.6 He suggested that customers who buy one 

stamp at a time and pay in cash are more likely to have low 

incomes and “may not appreciate the supposed ‘convenience’ 

of a higher price.” J.A. 100. The Greeting Card Association 

added that retail customers are accustomed to stamp prices that 

frequently are not divisible by five. J.A. 112. Disputing the 

Postal Service’s claims, Carlson also argued that the meaning 

of fifty-two cents is just as clear and straightforward as the 

meaning of fifty-five cents and noted that the public had never 

struggled to understand the price of stamps, even though that 

price had not been divisible by five for most of the nation’s 

6 Stamp booklets contain 20 stamps and stamp coils contain 100.
15

history. J.A. 97–98. These public comments called into 

question the justifications offered by the Postal Service, and 

therefore the Commission should have evaluated whether 

divisibility by five did, in fact, promote the statutory interest in 

“simplicity of structure.” See MCI WorldCom, 209 F.3d at 765. 

Second, the Commission did not address public comments 

arguing that the proffered justification for the stamp price hike 

misstated the “effect of rate increases upon the general public.”

See 39 U.S.C § 3622(c)(3). The Postal Service claimed that 

reduced surcharges for nonstandard first-class mail products

would mitigate the stamp price hike’s impact and suggested 

that in the future the Service would continue to raise rates in 

five-cent increments so that rates would need to be raised less 

frequently. J.A. 8–9. In his public comment, Carlson argued 

that rate reductions for nonstandard mail products could not 

meaningfully mitigate the effect of the stamp price hike 

because the reductions applied to only about three percent of 

first-class mail. Carlson also noted that the Postal Service had 

not committed to less frequent rate increases and that the fivecent increment simply meant higher prices. J.A. 103–05. The 

Commission’s analysis acknowledged that the Postal Service 

had not committed to less frequent rate increases and, in fact, 

expressly noted the Postal Service’s “flexibility” to depart from 

five-cent increases in future price adjustments. J.A. 208–09.

The Commission did not address Carlson’s other concerns 

about the stamp price hike’s effect on the general public, did 

not acknowledge that the public effect of the increase was a 

statutory factor, and did not explain how this factor fit into the 

Commission’s overall assessment of the stamp price hike’s 

compliance with the PAEA.

Third, the Commission failed to address public comments 

raising three additional statutory objectives and factors that 

weighed against a five-cent increase in the price of stamps. For 
16

example, the Greeting Card Association provided comments 

concerning “the available alternative means of sending and 

receiving letters and other mail matter at reasonable costs,” 39 

U.S.C. § 3622(c)(4). It argued the Commission should consider 

the risk that the stamp price hike would hasten the trend toward 

electronic bill payment systems. J.A. 115. The Association for 

Postal Commerce argued that increasing stamp prices by large 

amounts at infrequent intervals would undermine the statutory 

objective of “predictability and stability in rates,” 39 U.S.C.

§ 3622(b)(2). J.A. 89. Carlson argued that an unprecedented 

stamp price hike based solely on a frivolous appeal to the 

convenience of nickels over pennies was inconsistent with the 

statutory objective of maintaining “a just and reasonable 

schedule for rates,” 39 U.S.C. § 3622(b)(8). J.A. 104. These 

comments merited a response because they challenged the 

Commission’s primary rationale by raising substantial 

countervailing statutory considerations. See MCI WorldCom, 

209 F.3d at 765. Yet the Commission did not evaluate any of 

these statutory objectives and factors or explain how they 

should be weighed against the “simplicity of structure”

rationale to determine whether the stamp price hike was 

consistent with the framework of the PAEA.

In his appeal, Carlson largely repeats the arguments made

in comments before the Commission. In response, the 

Commission maintains it satisfied any obligation to consider 

the statutory objectives and factors in its rate-approval order by 

focusing on pricing flexibility, which is both an objective and 

a factor under the PAEA. See 39 U.S.C. § 3622(b)(4), (c)(7). 

Order 4875 noted that “subject to certain limitations, most 

prominently the price cap, the PAEA gives the Postal Service 

pricing flexibility within First-Class Mail.” Order No. 4875 at 

19–20. According to the Commission, the Order’s reference to 

the Postal Service’s pricing flexibility constitutes a sufficient

evaluation of the statutory objectives and factors. 
17

We conclude that the Commission fell short of the APA’s 

requirement for reasoned decisionmaking because it did not 

adequately analyze the stamp price hike’s compliance with all 

of the PAEA’s relevant statutory objectives and factors, 

particularly those raised in the public comments.7 See 

Newspaper Ass’n, 734 F.3d at 1210; Home Box Office, 567 

F.2d at 35–36. The Commission did not address whether the 

Postal Service’s claims about the convenience, 

straightforwardness, and understandability of prices divisible 

by five had anything to do with the PAEA’s requirement for 

“simplicity of structure,” and offered no explanation for why it 

could not undertake such an analysis in the time provided for 

its review. The Commission also failed to evaluate how other 

statutory objectives and factors might bear on the proposed rate 

change or outweigh the Postal Service’s reliance on “simplicity 

of structure.” Thus, the Commission failed to “demonstrate the 

rationality of its decision-making process by responding to 

those comments that are relevant and significant.” Grand 

Canyon Air Tour Coal. v. FAA, 154 F.3d 455, 468 (D.C. Cir. 

1998); see also MCI WorldCom, 209 F.3d at 765 (an agency 

must respond to comments “that can be thought to challenge a 

fundamental premise”). Because the Commission cannot 

7 We decline to adopt the Commission’s purported “blatant 

disregard” standard as the test for when the Commission must 

address statutory factors and objectives during a rulemaking on rates. 

This standard arises from the Commission’s post-hoc 

characterization of its regulations in an order setting forth the 

Commission’s approach to workshare discounts under 39 U.S.C. 

§ 3622(e). See Postal Regulatory Comm’n, Order No. 536 at 34 

(Sept. 14, 2010), available at 

https://www.prc.gov/Docs/70/70204/Order_No_536.pdf. It is not 

established by law, is not codified in any regulation, has no direct 

application to rates other than workshare discounts, lacks definition 

(as the Commission conceded during oral argument), and conflicts 

with the APA requirements described above.
18

determine whether a rate adjustment is “consistent with 

applicable law” without weighing the PAEA’s enumerated 

factors and objectives, the Commission also failed to comply 

with the system regulation in adopting the stamp price hike.

C.

We find unpersuasive the Commission’s argumentsthat its 

limited review of the stamp price hike was justified because the 

PAEA requires a quick decisionmaking process that does not 

allow sufficient time to evaluate the statutory objectives and 

factors. The Commission asserts that the stamp price hike 

satisfies the PAEA’s price cap and other quantitative factors, 

and therefore is valid even without a fuller consideration of the 

PAEA’s “qualitative” objectives and factors. In effect, the 

Commission argues that the demands of the PAEA modify the 

ordinary requirements of the APA that a decision be 

“reasonable and reasonably explained.” Nat’l Tel. Coop. Ass’n, 

563 F.3d at 540. 

Yet absent a clear statement, this court will not assume that 

a statute modifies the reasoned decisionmaking requirements 

of the APA. See 5 U.S.C. § 559 (“[A] [s]ubsequent statute may 

not be held to supersede or modify . . . [the APA] . . . except to 

the extent that it does so expressly.”); City of New York v. 

Permanent Mission of India to United Nations, 618 F.3d 172, 

203 (2d Cir. 2010) (“Subsequent organic statutes may 

supersede or modify APA requirements, but they must do so 

expressly.”); see also Dickinson v. Zurko, 527 U.S. 150, 155 

(1999). This comports with “this Court’s duty to interpret 

Congress’s statutes as a harmonious whole rather than at war 

with one another.” Epic Sys. Corp. v. Lewis, 138 S. Ct. 1612, 

1619 (2018). Moreover, the PAEA specifically incorporates 

the APA standards of review for Commission actions and 
19

nothing in the text or structure of the PAEA suggests the 

Commission can shortchange the requirements of the APA.

Since the enactment of the PAEA and in its system 

regulation, the Commission has maintained that Congress 

intended the Commission’s review of proposed rate changes to 

be simple enough to complete in forty-five days. Order No. 43, 

72 Fed. Reg. at 63,665. It claims that this timeline comes from

the PAEA, which provides:

The system for regulating rates and classes for marketdominant products shall . . . not later than 45 days before 

the implementation of any adjustment in rates under this 

section, . . .—

(i) require the Postal Service to provide public 

notice of the adjustment; 

(ii) provide an opportunity for review by the Postal 

Regulatory Commission; 

(iii) provide for the Postal Regulatory Commission to 

notify the Postal Service of any noncompliance of the 

adjustment with the limitation under subparagraph (A); 

and 

(iv) require the Postal Service to respond to the 

notice provided under clause (iii) and describe the 

actions to be taken to comply with the limitation under 

subparagraph (A).

39 U.S.C. § 3622(d)(1)(C). In its system regulation, the 

Commission interprets this provision to mean that “[t]he 

inference is strong that Congress contemplated that 

complicated or subjective compliance issues would be 

addressed during the annual compliance review, or through the 

complaint procedures of section 3662.” Order No. 43, 72 Fed. 

Reg. at 63,665. The Commission candidly acknowledges that 

it prioritizes the speed of the rulemaking process over its 
20

thoroughness and scope, based on the view that it could “give 

close scrutiny to only a limited number of compliance issues in 

the time available” under 39 U.S.C. § 3622(d)(1)(C). Id. The 

Commission has consistently maintained this interpretation in 

subsequent orders as well as in its litigating position here.

The Commission’s interpretation, however, is contrary to 

the plain language of the statute when read as a whole. 

“[C]ourts must give effect to the clear meaning of statutes as 

written,” Estate of Cowart v. Nicklos Drilling Co., 505 U.S. 

469, 476 (1992), which includes “the broader context of the 

statute as a whole,” Robinson v. Shell Oil Co., 519 U.S. 337, 

341 (1997). Even an agency’s consistent and longstanding 

interpretation, if contrary to statute, can be overruled. “A 

regulation’s age is no antidote to clear inconsistency with a 

statute.” Brown v. Gardner, 513 U.S. 115, 122 (1994); see also

SEC v. Sloan, 436 U.S. 103, 118 (1978) (“Nor does the 

existence of a prior administrative practice, even a wellexplained one, relieve us of our responsibility to determine 

whether that practice is consistent with the agency’s statutory 

authority.”); Se. Ala. Med. Ctr. v. Sebelius, 572 F.3d 912, 920 

(D.C. Cir. 2009) (“No matter how consistent its past practice, 

an agency must still explain why that practice comports with 

the governing statute and reasoned decisionmaking. . . . [N]o 

amount of historical consistency can transmute an unreasoned 

statutory interpretation into a reasoned one.”); Antonin Scalia, 

Judicial Deference to Administrative Interpretations of Law, 

1989 Duke L.J. 511, 517 (1989) (“[T]here is no longer any 

justification for giving special deference to long-standing and 

consistent agency interpretations of law.”). 

The Commission misreads the PAEA, which requires four 

actions to be completed “not later than 45 days before the 

implementation of any adjustment in rates under this section.” 

39 U.S.C. § 3622(d)(1)(C). One of the actions is “review by the 
21

Postal Regulatory Commission.” Id. § 3622(d)(1)(C)(ii). The 

PAEA is silent about the amount of time the Commission may

take during its review. Congress did not limit the scope and 

duration of the Commission’s review, but did charge the 

Commission with setting rates through rulemaking (rather than 

adjudication), with the due consideration required by the APA.

Moreover, other provisions within the PAEA provide 

relevant context, further reinforcing that Congress did not 

abbreviate the Commission’s review period. “[I]n expounding 

a statute, we must not be guided by a single sentence . . . but 

look to the provisions of the whole law.” Del. Dep’t of Nat. 

Res. & Envtl. Control v. EPA, 895 F.3d 90, 97 (D.C. Cir. 2018) 

(quoting U.S. Nat’l Bank of Or. v. Indep. Ins. Agents of Am., 

Inc., 508 U.S. 439, 455 (1993)). The PAEA establishes a 

ninety-day timeline for “expedited” review of rate changes 

under “extraordinary or exceptional circumstances.” 39 U.S.C. 

§ 3622(d)(1)(E). Providing for an expedited review in 

exceptional circumstances that could take up to ninety days 

belies the Commission’s claim that the PAEA requires an 

ordinary review to be completed in just half that time. 

Similarly, reading the PAEA alongside the APA suggests that 

if any inference should be drawn from the forty-five day delay

period, it would be that Congress wanted the public to have 

more notice before a rate change. The APA requires a 

minimum of thirty days between the announcement of a final 

rule and its effective date. 5 U.S.C. § 553(d). The PAEA’s 

forty-five day minimum is longer than the ordinary delay 

period and the statute is silent regarding the amount of time 

allocated for the Commission’s consideration of a rate 

adjustment.

As the Commission admitted at oral argument, it is unable 

to locate a short review period within the PAEA’s text or 

structure. Instead, the Commission leans heavily on legislative 
22

history and defends its limited and expedited consideration 

during the rate approval process with citations to a Senate 

Report, as well as to a post-enactment letter signed by two 

senators and submitted as part of the public comments on the 

proposed system regulation. Yet when the statutory text is 

clear, legislative history should not be used to muddy its 

meaning. See Ratzlaf v. United States, 510 U.S. 135, 147–48 

(1994). And, by definition, post-enactment statements of 

members of Congress are not even part of the legislative 

history. Bruesewitz v. Wyeth LLC, 562 U.S. 223, 242 (2011) 

(“Post-enactment legislative history (a contradiction in terms) 

is not a legitimate tool of statutory interpretation.”). The PAEA 

is silent about how long the Commission has to approve a 

proposed rate adjustment and legislative history cannot provide 

the express statement necessary to eliminate the reasoned 

decisionmaking required by the APA. See 5 U.S.C. § 559. 

Nothing in the PAEA justifies a truncated rulemaking analysis 

that fails to meet the requirements of the APA.

We also reject the Commission’s argument that it can 

satisfy the PAEA by deferring consideration of the statutory 

factors and objectives until its annual compliance review or in 

the adjudication of individual complaints that a specific rate 

regulation is inconsistent with the PAEA. Standing alone, 

annual reviews and complaint adjudications do not satisfy the 

PAEA’s requirement that the Commission create a “modern 

system for regulating rates” that is specific to market-dominant 

products and reflects the concerns enumerated in 39 U.S.C. 

§ 3622(b)–(c). The annual reviews and complaint 

adjudications were established by Congress in separate 

sections of the PAEA that apply to postage rates generally and 

reflect no special consideration for concerns specific to marketdominant products. See id. §§ 3653(b), 3662(a). Complaints 

and annual reviews take place after rulemaking is complete. 

Such post-implementation review of rates shifts the burden of 
23

proof to the public to demonstrate the unreasonableness of rates

that have already been adopted, instead of requiring the 

Commission to demonstrate through reasoned rulemaking that 

its proposed rates comply with the APA and PAEA. See, e.g.,

Nat’l Lime Ass’n v. EPA, 627 F.2d 416, 433 (D.C. Cir. 1980) 

(“[A]n initial burden of promulgating and explaining a nonarbitrary, non-capricious rule rests with the [a]gency.”).

In addition, as a practical matter, an invalid rate increase 

can result in overpayment to the Postal Service without any 

means of recovery. See 39 U.S.C. § 3681 (prohibiting 

reimbursement for any amount paid pursuant to a rate later 

determined to be unlawful). Moreover, the complaints and 

annual reviews have separate dockets, and there is no 

mechanism for taking into consideration issues that were raised 

in the public comment period but were not addressed by the 

Commission during the initial rulemaking. 

The statutory structure confirms the annual review and 

separate complaint process cannot provide a post-hoc 

rationalization of rate adjustments. “Just as Congress’ choice 

of words is presumed to be deliberate, so too are its structural 

choices.” Univ. of Tex. Sw. Med. Ctr. v. Nassar, 570 U.S. 338, 

353 (2013). The annual review and complaint process exist 

apart from the regulatory system for market-dominant products 

and cannot satisfy the PAEA framework, the APA’s 

requirements for reasoned decisionmaking, or the system 

regulation’s requirement that the Commission determine 

whether a proposed rate adjustment is “consistent with 

applicable law” in the development and issuance of a rate 

approval order.

* * *

Congress directed the Commission to serve as more than 

just a rubber stamp of the Postal Service’s proposed rate 
24

increases. The PAEA establishes a robust rulemaking process 

for the Commission, subjecting rate-change proposals to the 

deliberative and participatory process of notice-and-comment 

rulemaking under the APA. By failing to consider relevant 

statutory objectives and factors and declining to respond to 

significant public comments, the Commission violated the 

APA when it approved the stamp price hike.

III.

We must next determine whether the stamp price hike can 

be severed from the other parts of Order 4875, which includes 

a rate adjustment for first-class mail products as well as 

adjustments for other mail categories. The APA requires a 

reviewing court to “hold unlawful and set aside agency action” 

that is arbitrary and capricious. 5 U.S.C. § 706(2). An “agency 

action” may be either “the whole or a part of an agency rule 

[or] order.” 5 U.S.C. § 551(13) (incorporated by 5 U.S.C. 

§ 701(b)(2)). Thus, the APA permits a court to sever a rule by 

setting aside only the offending parts of the rule. See, e.g., 

K Mart Corp. v. Cartier, Inc., 486 U.S. 281, 294 (1988); 

Virginia v. EPA, 116 F.3d 499, 500–01 (D.C. Cir. 1997). Two 

conditions limit the exercise of this power. First, the court must 

find that “the agency would have adopted the same disposition 

regarding the unchallenged portion [of the regulation] if the 

challenged portion were subtracted.” Sierra Club v. FERC, 867 

F.3d 1357, 1366 (D.C. Cir. 2017). Second, the parts of the 

regulation that remain must be able to “function sensibly 

without the stricken provision.” Sorenson Commc’ns. Inc. v. 

FCC, 755 F.3d 702, 710 (D.C. Cir. 2014) (quoting MD/DC/DE 

Broads. Ass’n v. FCC, 236 F.3d 13, 22 (D.C. Cir. 2001)).

Carlson requests that the court invalidate the five-cent 

stamp price hike. We determine that the category of first-class 

rate adjustments, including the stamp price hike, are a single 
25

agency action that can be severed from the other parts of the 

Order. Although only the stamp price hike was at issue in this 

case, that increase cannot be separated from the rate adjustment 

for the category of first-class mail because the first-class 

provisions are “intertwined.” Epsilon Elecs., Inc. v. Dep’t of 

Treasury, Office of Foreign Assets Control, 857 F.3d 913, 929 

(D.C. Cir. 2017). The PAEA links the prices of all first-class 

mail products, including stamps, by applying a rate cap to all 

first-class mail rather than to individual products within that 

category. See 39 U.S.C. § 3622(d)(2). The ten percent increase 

in the first-class letter stamp limited the Commission’s ability 

to raise rates for other first-class mail products. In fact, the 

Order lowered rates for nonstandard first-class mail products

and still fell barely within the rate cap. The Commission also 

approved the changes in rates for first-class mail as a package, 

treating them together in Ordering Paragraph One. See North 

Carolina v. FERC, 730 F.2d 790, 796 (D.C. Cir. 1984) (noting 

agency statement that it approved three agreements as “a 

comprehensive settlement which, as a package, appears 

reasonable”). 

The first-class mail adjustment, however, has no 

connection with the Order’s other categories, which are 

concerned primarily with rate changes for marketing mail, 

periodicals, package services, overweight item charges, and 

special services. These rates are not interconnected by statute

and the Commission analyzed them independently in separate 

ordering paragraphs. We see no reason why these other rates 

cannot “function sensibly” without the first-class mail 

category. MD/DC/DE Broads. Ass’n, 236 F.3d at 22. Because 

both requirements for severability are satisfied, we vacate the 

first-class rate adjustments and leave the remainder of Order 

4875 in place.
26

IV.

Although the five-cent stamp price hike may have gone 

unnoticed by many, the American Revolution was fomented in 

part by ordinary people who objected to taxation through 

stamps.

8 Carlson’s objections arise in less fraught times. We 

conclude that this stamp price hike violated the APA because 

the Commission failed to consider the relevant policies of the 

PAEA, particularly those raised in the public comments. We 

therefore grant Carlson’s petition for review, vacating the part 

of Order 4875 that includes the stamp price hike and the rate 

adjustments to the category of first-class mail.

So ordered.

8 See, e.g., Justin DuRivage & Claire Priest, The Stamp Act and the 

Political Origins of American Legal and Economic Institutions, 88 

S. Cal. L. Rev. 875, 875 (2015) (“The British Parliament’s enactment 

of the Stamp Act of 1765 is widely acknowledged as a starting point 

for the acceleration of tensions that led to the Declaration of 

Independence in 1776.”) (citing Edmund S. Morgan, The Birth of the 

Republic, 1763-89, at 18–28 (3d ed. 1992); Gordan S. Wood, The 

American Revolution 29–37 (2003)).
27

APPENDIX

Title 39 U.S.C. § 3622(b) provides:

“[The Commission’s system for regulating rates and classes]

shall be designed to achieve the following objectives, each of 

which shall be applied in conjunction with the others:

(1) To maximize incentives to reduce costs and 

increase efficiency.

(2) To create predictability and stability in rates. 

(3) To maintain high quality service standards 

established under section 3691.

(4) To allow the Postal Service pricing flexibility.

(5) To assure adequate revenues, including retained 

earnings, to maintain financial stability. 

(6) To reduce the administrative burden and increase 

the transparency of the ratemaking process. 

(7) To enhance mail security and deter terrorism. 

(8) To establish and maintain a just and reasonable 

schedule for rates and classifications, however 

the objective under this paragraph shall not be 

construed to prohibit the Postal Service from 

making changes of unequal magnitude within, 

between, or among classes of mail. 

(9) To allocate the total institutional costs of the 

Postal Service appropriately between marketdominant and competitive products.”
28

Title 39 U.S.C. § 3622(c) provides:

“In establishing or revising such system, the Postal Regulatory 

Commission shall take into account:

(1) the value of the mail service actually provided 

each class or type of mail service to both the 

sender and the recipient, including but not limited 

to the collection, mode of transportation, and 

priority of delivery; 

(2) the requirement that each class of mail or type of 

mail service bear the direct and indirect postal 

costs attributable to each class or type of mail 

service through reliably identified causal 

relationships plus that portion of all other costs of 

the Postal Service reasonably assignable to such 

class or type; 

(3) the effect of rate increases upon the general 

public, business mail users, and enterprises in the 

private sector of the economy engaged in the 

delivery of mail matter other than letters; 

(4) the available alternative means of sending and 

receiving letters and other mail matter at 

reasonable costs;

(5) the degree of preparation of mail for delivery into 

the postal system performed by the mailer and its 

effect upon reducing costs to the Postal Service; 

(6) simplicity of structure for the entire schedule and 

simple, identifiable relationships between the 

rates or fees charged the various classes of mail 

for postal services; 
29

(7) the importance of pricing flexibility to encourage 

increased mail volume and operational 

efficiency; 

(8) the relative value to the people of the kinds of 

mail matter entered into the postal system and the 

desirability and justification for special 

classifications and services of mail; 

(9) the importance of providing classifications with 

extremely high degrees of reliability and speed of 

delivery and of providing those that do not 

require high degrees of reliability and speed of 

delivery; 

(10) the desirability of special classifications for both 

postal users and the Postal Service in accordance 

with the policies of this title, including 

agreements between the Postal Service and postal 

users, when available on public and reasonable 

terms to similarly situated mailers, that—

(A) either—

(i) improve the net financial 

position of the Postal Service 

through reducing Postal Service 

costs or increasing the overall 

contribution to the institutional 

costs of the Postal Service; or 

(ii) enhance the performance of mail 

preparation, processing, 

transportation, or other 

functions; and 

(B) do not cause unreasonable harm to the 

marketplace. 
30

(11) the educational, cultural, scientific, and 

informational value to the recipient of mail 

matter; 

(12) the need for the Postal Service to increase its 

efficiency and reduce its costs, including 

infrastructure costs, to help maintain high quality, 

affordable postal services; 

(13) the value to the Postal Service and postal users of 

promoting intelligent mail and of secure, senderidentified mail; and 

(14) the policies of this title as well as such other 

factors as the Commission determines 

appropriate.”