City of Billings v. Transportation Security Administration and David P. Pekoske, Administrator

United States Court of Appeals
FOR THE DISTRICT OF COLUMBIA CIRCUIT
Argued October 17, 2024 Decided August 22, 2025
No. 23-1290
CITY OF BILLINGS, ET AL.,
PETITIONERS
v.
TRANSPORTATION SECURITY ADMINISTRATION AND DAVID P.
PEKOSKE, ADMINISTRATOR,
RESPONDENTS
Consolidated with 23-1328
On Petitions for Review of a Final Action
of the Transportation Security Administration
Melissa C. Allison argued the cause for petitioners. With
her on the briefs were David S. Mackey and Carlos R. Rosende.
Leif Overvold, Attorney, U.S. Department of Justice,
argued the cause for respondents. With him on the brief were
Brian M. Boynton, Principal Deputy Assistant Attorney
General, and Sharon Swingle, Attorney.

-- 1 of 14 --

2
Before: SRINIVASAN, Chief Judge, WALKER, Circuit
Judge, and ROGERS, Senior Circuit Judge.
Opinion for the Court filed by Chief Judge SRINIVASAN.
SRINIVASAN, Chief Judge: In 2020, the Transportation
Security Administration proposed a rule to address “insider
threats” in secured areas in airports—the danger that aviation
workers with unescorted access to secured airport areas could
enable weapons or other dangerous items to be brought on
board aircraft. The agency, however, did not give notice of the
proposed rule to the public or allow for public comments.
Rather than apply ordinary notice-and-comment procedures,
TSA gave notice and an opportunity to comment to airport
operators alone.
TSA finalized its rule nearly three years later. The final
rule, which the parties call the “National Amendment,”
requires the nation’s largest airports to physically screen
aviation workers entering certain secured areas. The National
Amendment also requires airport operators to purchase and
deploy explosives-detecting equipment. An airport operator’s
failure to comply with the rule’s requirements can result in a
civil enforcement action brought by TSA.
Petitioners challenge the National Amendment on various
grounds, including that TSA had to go through notice-and-
comment procedures to promulgate the rule. Because we agree
with petitioners on that ground, we have no occasion to reach
their remaining challenges. In view of the security risks that
might come about in the absence of the rule, we will withhold
our mandate, setting it aside until TSA adopts a new rule or
informs the court that it no longer believes any rule is
necessary.

-- 2 of 14 --

3
I.
A.
Congress required the Transportation Security
Administration (TSA) to mandate background checks for
“airport security screening personnel” and other individuals
with access to secured areas in airports. 49 U.S.C. § 114(f)(12).
TSA must also “prescribe regulations to protect passengers and
property” from criminal activity. Id. § 44903(b). And it must
provide for the screening of all “passengers” boarding flights
in the United States and of any property “that will be carried
aboard a passenger aircraft.” 49 U.S.C. § 44901(a).
Congress additionally vested TSA with broad authority
over airport operators to ensure that the agency could carry out
its duty to “shore up our nation’s civil aviation security.”
Olivares v. TSA, 819 F.3d 454, 459 (D.C. Cir. 2016); see, e.g.,
49 U.S.C. §§ 114(l)(1), 44903(g)(2)(A). And Congress
transferred the enforcement of various regulations governing
access to secured airport areas from the Federal Aviation
Administration—which had originally promulgated them—to
TSA.
Under those regulations, airport operators must adopt and
implement a TSA-approved security program that prevents
“the introduction of an unauthorized weapon, explosive, or
incendiary onto an aircraft.” 49 C.F.R. § 1542.101(a)(1); see
also id. §§ 1542.103, 1542.105(a). The regulations also require
airports to “establish at least one secured area” and take
measures to “prevent and detect . . . unauthorized entry” there.
Id. §§ 1542.201(a), (b)(1). Secured areas include areas in
which passengers board and deboard a plane and luggage is
sorted and loaded. Id. § 1540.5. The regulations require

-- 3 of 14 --

4
airports that regularly service large aircraft to maintain a
“security identification display area” (or SIDA) at each secured
area and other areas in the airport. Id. §§ 1542.205(a)(1)–(3).
Airports subject to that requirement must establish an
identification system to “prevent the unauthorized presence
and movement of individuals in the SIDA” and train their
employees before granting them unescorted SIDA access. Id.
§§ 1542.205(b)(1), (3).
Airport operators wishing to modify their approved
security programs must submit a request to a designated TSA
official, who can approve the proposed amendment upon
concluding that “safety and the public interest will allow it.”
Id. § 1542.105(b)(3). Alternatively, TSA can itself amend a
security program if it determines that doing so would benefit
“safety and the public interest.” Id. § 1542.105(c). Before
finalizing such a sua sponte amendment, the agency must give
the affected airport operator notice and an opportunity to
comment on the proposal. Id. § 1542.105(c)(1).
B.
In recent years, TSA and Congress have grown
increasingly concerned about the security risk posed by airport
workers with unescorted access to secured airport areas, who
can usually enter those areas without undergoing any physical
screening. See, e.g., FAA Extension, Safety, and Security Act
of 2016, Pub. L. No. 114-90, § 3407 (2016) (directing TSA to
“expand the use of transportation security officers and
inspectors to conduct . . . physical inspections of airport
workers”). TSA fears that airport workers could give terrorist
groups and criminal organizations a potential means of gaining
access to secured areas without a security screening. Although
present efforts to mitigate insider threats—primarily, vetting

-- 4 of 14 --

5
before granting unescorted access—have generally proved
effective, TSA has come to believe that more is warranted.
In October 2020, TSA sought to address its concerns by
requiring airport workers to undergo random physical
inspections before entering certain secured areas. Instead of
initiating a notice-and-comment rulemaking, however, the
agency notified airport operators of its intention to amend all
airport security programs to establish a rule and gave them—
but no one else—sixty days to comment. And instead of
assuming responsibility to carry out the newly prescribed
screening, TSA proposed to require airport operators to
conduct most of the physical screening at secured-area entry
points. The proposed rule also called on airport operators to
develop a plan for acquiring and deploying explosives-
detection equipment within eighteen months of the proposed
rule’s effective date.
TSA’s proposal, known in the industry as the National
Amendment, met a frosty reception among airport operators.
Many operators commented that TSA should itself take
primary responsibility to screen aviation workers. The Airport
Council International-North America (ACI-NA), a trade
organization and a petitioner in this case, criticized TSA for
imposing a costly requirement on airports that had yet to
recover from the impact of the COVID-19 pandemic, argued
that the agency lacked statutory authority to do so, and objected
to the agency’s decision to forgo the public notice-and-
comment procedures contemplated by the Administrative
Procedure Act. In all, the agency received comments from 170
airport operators as well as trade organizations like ACI-NA,
nearly all of which expressed concerns with TSA’s proposal.
TSA nonetheless finalized the National Amendment in
April 2023 with few substantive changes. The National

-- 5 of 14 --

6
Amendment clarified that screening could be accomplished
through non-contact, technology-based measures. It also
explained that airports could rely on screening operations in
place before the rule’s effective date if they include an element
of randomization, meet the minimum screening requirements,
and encompass the covered access points. As with the initial
proposal, though, airport operators subject to the National
Amendment must themselves conduct the newly required
random screening of aviation workers entering secured areas,
including searching their person and their “accessible
property.” J.A. 670.
In its responses to the comments it received, TSA rejected
the suggestion that it—rather than airport operators—should do
the screening, explaining that airport security is a “shared
responsibility” between the agency and airports. The agency
also sought to justify its decision to forgo the APA’s notice-
and-comment procedures and instead proceed through the
procedures applicable to an amendment of airport security
programs. The agency regulations setting out the latter
procedures, TSA explained, allow for approval of amendments
to airport security programs after giving affected airport
operators an opportunity to comment. Here, TSA had
complied with those procedures.
C.
Petitioners include various municipalities that operate
airports along with ACI-NA. Each petitioner submitted timely
reconsideration requests to TSA pursuant to 49 C.F.R.
1542.105(c)(2) and asked the agency to withdraw the National
Amendment. The request submitted by one petitioner,
Massport, is illustrative. It requested the agency to withdraw
the amendment on multiple grounds, including: that the
governing statute gives TSA, not local airport operators, the

-- 6 of 14 --

7
duty to screen aviation workers; that the APA required the
agency to provide the public with notice and an opportunity to
comment before finalizing the rule; and that the rule unlawfully
commandeers local officials to implement a federal regulatory
scheme.
The agency rejected all the petitions for reconsideration.
Among other responses, TSA reiterated its view that it had no
duty to undertake a notice-and-comment rulemaking because
its own regulations allowed it to amend airport security
programs by giving airport operators—rather than the public
more broadly—notice and a chance to comment.
Petitioners now seek review of TSA’s denial of their
petitions for reconsideration. The challengers also moved for
a stay of the National Amendment pending our review, which
a panel of this court denied.
II.
Petitioners renew all the arguments they previously raised
before the agency, including that TSA was required to engage
in notice-and-comment rulemaking when promulgating the
National Amendment. Because we agree with petitioners on
that score, we have no occasion to reach their other challenges
to the rule.
At the outset, TSA does not contest petitioners’ standing
to pursue that claim. That is understandable, as our precedents
demonstrate petitioners’ standing to raise their notice-and-
comment challenge. See WildEarth Guardians v. Jewell, 738
F.3d 298, 306 (D.C. Cir. 2013); Sugar Cane Growers Coop. of
Fla. v. Veneman, 289 F.3d 89, 96–97 (D.C. Cir. 2002).

-- 7 of 14 --

8
The APA’s notice-and-comment procedures are set out in
5 U.S.C. § 553(b), and the statute generally assumes that an
agency’s exercise of rulemaking must abide by those
procedures unless certain exceptions apply. One such
exception is for “interpretative” (or interpretive) rules, as
opposed to legislative rules. 5 U.S.C. § 553(b)(4)(A). So in
determining whether a rule is subject to the APA’s notice-and-
comment provisions, we ordinarily ask whether the rule is a
legislative rule (which generally must go through notice-and-
comment procedures) or an interpretive rule (which need not).
Legislative rules have the “force and effect of law,”
Encino Motorcars, LLC v. Navarro, 579 U.S. 211, 215 (2016),
and usually bring about “a substantive change in existing law
or policy,” Mendoza v. Perez, 754 F.3d 1002, 1021 (D.C. Cir.
2014). Interpretive rules, by contrast, ordinarily lack the force
of law and instead only “advise the public of the agency’s
construction of the statutes and rules which it administers.”
Shalala v. Guernsey Mem’l Hosp., 514 U.S. 87, 99 (1995)
(quotation marks omitted). The statute or rule being interpreted
might itself have the force of law, but the interpretive rule
merely sets out the agency’s view of that preexisting legal
obligation rather than establish a legal obligation of its own.
An interpretive rule, in other words, “does not itself alter the
rights or interests of parties” in the manner of a legislative rule.
Chamber of Com. of U.S. v. Dep’t of Lab., 174 F.3d 206, 211
(D.C. Cir. 1999) (citation and quotation marks omitted).
Judged by those standards, the National Amendment is
plainly a legislative rule. The National Amendment’s basic
objective is to impose new obligations on airport operators by
requiring them, among other things, to physically screen
aviation workers entering secured airport areas. The rule states
that airport operators “must conduct aviation worker
screening” and “must” also develop a plan for acquiring and

-- 8 of 14 --

9
deploying explosives-detection equipment. J.A. 669, 671.
And those newly instituted obligations have the force and
effect of law: they are legally binding on airport operators and
are subject to enforcement by the agency.
TSA has made that understanding explicit. Soon after
adopting the National Amendment, TSA issued a “notice . . . to
inform airports and other aviation entities regulated by the
Transportation Security Administration” of how the agency
would enforce the rule’s requirements upon their taking effect.
TSA, Notice of Informed Compliance: Aviation Worker
Screening, at 1 (Sept. 6, 2023), J.A. 996. The agency advised
that, while “TSA is not extending or modifying the effective
date of the [National Amendment],” it “is providing a 12-
month period of ‘informed compliance’ for the requirements
in” the rule. Id. During that initial period, the agency
explained, it “will not pursue civil enforcement action against
airports that are making good faith efforts toward
implementation of the requirements of the [National
Amendment].” Id. But after that “informed compliance”
period, “failure to comply with all applicable aviation worker
screening requirements will be subject to full enforcement
action by TSA.” Id. at 2, J.A. 997.
As that notice makes clear, the National Amendment has
the force and effect of law: it imposes new legal requirements
on airport operators across the country and those requirements
are subject to civil enforcement by the agency. That is a
quintessential legislative rule. Indeed, the very fact that the
National Amendment has an effective date bespeaks a
legislative rule—there would be little reason to set an effective
date if the rule merely interpreted a preexisting obligation as
opposed to instituting a new one. See Guedes v. ATF, 920 F.3d
1, 18 (D.C. Cir. 2019). After all, TSA adopted the rule
precisely because airport workers were not being screened

-- 9 of 14 --

10
before entering secured airport areas. The agency promulgated
a rule imposing “new substantive obligations” intended to
redress the perceived security gap. Elec. Privacy Info. Ctr. v.
Dep’t of Homeland Sec., 653 F.3d 1, 6 (D.C. Cir. 2011). And
in doing so, it “explicitly invoked its general legislative
authority,” Am. Mining Cong. v. Mine Safety & Health Admin.,
995 F.2d 1106, 1109 (D.C. Cir. 1993), citing its general
authority to issue regulations, 49 U.S.C. § 114(l)(1), as well as
its mandate to provide for the screening of individuals “before
entry into a secured area,” id. § 44903(h)(4). See, e.g.,
Disposition of Massport Pet. at 2, 5–7 (J.A. 881, 884–86).
TSA ultimately does not dispute that the National
Amendment bears those fundamental characteristics of a
legislative rule. Instead, TSA contends it could forgo giving
notice and an opportunity to comment to the public because of
an agency regulation, 49 C.F.R. § 1542.105(c). That
regulation, TSA observes, contemplates that the agency can
“amend” an airport operator’s “security program” by
“send[ing] to the airport operator a notice . . . of the proposed
amendment” and “fixing a period of not less than 30 days
within which the airport operator may submit written”
comment. Id. (emphasis added). And here, TSA submits, it
provided notice and an opportunity to comment to airport
operators in accordance with that regulation, even if it did not
provide notice and an opportunity to comment to the broader
public.
Even assuming TSA correctly understood and complied
with its regulation, an agency’s adherence to its own
regulations does not somehow enable it to bypass the APA.
The APA’s notice-and-comment provisions set out specific
exceptions for interpretive rules, rules concerning “military or
foreign affairs,” and rules addressing internal agency
management. See 5 U.S.C. §§ 553(a)(1)–(2), (b)(A). The

-- 10 of 14 --

11
statute also permits agencies to forgo notice-and-comment
procedures if they can establish “good cause” to believe
adherence to the procedures would be “impracticable,
unnecessary, or contrary to the public interest.” Id. §
553(b)(B). TSA does not claim to fit within the good-cause—
or any other—exception here. What the APA generally does
not except from its rulemaking procedures are legislative rules.
As to those, an agency cannot simply rulemake its way out of
the APA’s requirements for rulemaking.
TSA suggests that public notice and comment would have
limited value in these circumstances because the National
Amendment principally affects airport operators, not “the
public at large,” and because the agency could (and likely
would) refuse to disclose information about its regulatory plans
regardless. TSA Br. 68–69. The APA, though, does not
contemplate an agency’s forgoing the statute’s notice-and-
comment requirements based on the agency’s own assumption
that there is a limited need to hear from the public in a given
instance. To the contrary, a central object of requiring that the
public be afforded notice and an opportunity to comment is to
assure that the agency fully understands the potential impact of
a proposed rule before finalizing it. Public notice and
comment, that is, might alter an agency’s initial assumptions
about whether (and how) a proposed rule affects the public at
large. See Humane Soc’y of the United States v. Dep’t of
Agric., 41 F.4th 564, 568 (D.C. Cir. 2022) (recognizing that
notice-and-comment procedures “foster public participation
and facilitate reasoned decisionmaking”).
True, the National Amendment’s requirements do not
directly affect the general public in the same way as
requirements for screening of airline passengers. Cf. Elec.
Privacy Info. Ctr., 653 F.3d at 3. But it would be wrong to say
that the National Amendment does not directly affect anyone

-- 11 of 14 --

12
other than airport operators. Most obviously, the rule affects
the aviation workers who must undergo a physical screening
before entering a secured area. Those workers might have
provided meaningful input about the proposed rule had TSA
given them an opportunity to comment. The APA required
affording them that opportunity.
TSA expresses concerns that if it cannot adopt the National
Amendment under the procedures for amending an airport
security program set out in its regulation, 49 C.F.R. §
1542.105(c), then it may never be able to amend an airport
security program pursuant to those procedures. Whatever may
be the availability of those procedures in the case of an
adjustment to a particular airport’s security program, the
across-the-board establishment of new, legally binding
requirements here—which the agency itself terms a “National
Amendment”—is a legislative rule. Cf. Safari Club Int’l v.
Zinke, 878 F.3d 316, 332–33 (D.C. Cir. 2017)) (distinguishing
adjudications from rules, which typically “announce[]
generally applicable legal principles”). Depending on the
circumstances, the Agency could also seek to establish good
cause for avoiding the APA’s procedural requirements. See 5
U.S.C. § 553(b)(3)(B); Jifry v. FAA, 370 F.3d 1174, 1179–80
(D.C. Cir. 2004). But absent that showing, and regardless of
the scope of the agency’s latitude to forgo the APA’s notice-
and-comment provisions in other contexts, the National
Amendment is a legislative rule subject to those provisions.
III.
Having concluded that TSA should have adhered to
notice-and-comment procedures in promulgating the National
Amendment, we now turn to the remedy. We have previously
granted vacatur when an agency adopted a rule without abiding
by the APA’s notice-and-comment requirements. See, e.g.,

-- 12 of 14 --

13
Daimler Trucks North Am. LLC v. EPA, 737 F.3d 95, 103 (D.C.
Cir. 2013) (explaining that the court “typically vacates rules
when an agency ‘entirely fail[s]’ to provide notice and
comment” (citation omitted)); Am. Pub. Gass Ass’n v. Dep’t of
Energy, 72 F.4th 1324, 1342–43 (D.C. Cir. 2023); Chamber of
Com. v. SEC, 443 F.3d 890, 908 (D.C. Cir. 2006); Shell Oil Co.
v. EPA, 950 F.2d 741, 765 (D.C. Cir. 1991). But see Sugar
Cane Growers, 289 F.3d at 98 (granting remand without
vacatur when agency did not adhere to notice-and-comment
procedures). We grant the ordinary remedy of vacatur here.
At the same time, TSA adopted the National Amendment
based on significant concerns about the risks to aviation
security absent the screening requirements established by the
rule, and the rule has been in place since it took effect in
September 2023. In these circumstances, rather than compel
immediate disestablishment of the rule based on the agency’s
failure to promulgate it pursuant to the APA’s notice-and-
comment procedures, we consider it appropriate to withhold
issuance of our mandate, see Fed. R. App. P. 41(b), until TSA
has an opportunity to adopt a procedurally sound rule (or, in
the event the agency no longer considers it necessary to
promulgate a rule, to so inform the court). That approach is
supported by our precedents. See, e.g., Cboe Futures Exch. v.
SEC, 77 F.4th 971, 982 (D.C. Cir. 2023); Chambers of Com.,
443 F.3d at 909 (collecting cases).
Accordingly, our mandate will issue upon the agency’s
informing the court that it has adopted a final rule consistent
with the APA’s procedural requirements (or has determined
that a rule is no longer needed). In the interim, the agency
should submit a periodic status report every 60 days apprising
the court of its progress.
* * * * *

-- 13 of 14 --

14
For the foregoing reasons, we grant the petitions for
review, vacate the National Amendment, and withhold our
mandate under the conditions set out in this opinion.
So ordered.

-- 14 of 14 --