United States Court of Appeals 

for the Federal Circuit ______________________

CODY L. ADAMS, ROSE M. ADAMSON, JOSEPH P. 

AGIUS, DARA W. ALLICK, JENNIFER A. ANGEL, 

MICHAEL T. ANGELO, SAMMY APONTE, ALICIA 

K. AUSTIN-ZITO, LUKE M. BADARACCO, CHAD J. 

BARGSTEIN, ET AL.,

Plaintiffs-Appellants

v.

UNITED STATES,

Defendant-Appellee

______________________

2021-1662

______________________

Appeal from the United States Court of Federal Claims 

in No. 1:20-cv-00783-CFL, Senior Judge Charles F. Lettow.

______________________

Decided: February 14, 2023

______________________

MOLLY A. ELKIN, McGillivary Steele Elkin LLP, Washington, DC, argued for plaintiffs-appellants. Also represented by THEODORE REID COPLOFF, GREGORY K.

MCGILLIVARY.

 ALBERT S. IAROSSI, Commercial Litigation Branch, 

Civil Division, United States Department of Justice, Washington, DC, argued for defendant-appellee. Also represented by BRIAN M. BOYNTON, ERIC P. BRUSKIN, ERIC 

Case: 21-1662 Document: 68 Page: 1 Filed: 02/14/2023
2 ADAMS v. US

LAUFGRABEN, PATRICIA M. MCCARTHY, CATHARINE 

PARNELL, LIRIDONA SINANI; ADAM GARRET EISENSTEIN,

DOUGLAS SETH GOLDRING, Office of General Counsel, Federal Bureau of Prisons, United States Department of Justice, Washington, DC.

 CRAIG BECKER, American Federation of Labor and Congress of Industrial Organizations, Washington, DC, for 

amicus curiae The American Federation of Labor and Congress of Industrial Organizations. Also represented by

MATTHEW GINSBURG, RAVEN HALL.

 ALLISON GILES, National Treasury Employees Union,

Washington, DC, for amicus curiae National Treasury Employees Union. Also represented by PARAS NARESH SHAH, 

JULIE M. WILSON.

______________________

Before MOORE, Chief Judge, NEWMAN, LOURIE, DYK,

PROST, REYNA, TARANTO, CHEN, HUGHES, STOLL,

CUNNINGHAM, and STARK, Circuit Judges.

Opinion for the court filed by Circuit Judge CHEN, in 

which MOORE, Chief Judge, LOURIE, DYK, PROST,

TARANTO, HUGHES, STOLL, CUNNINGHAM, and STARK,

Circuit Judges, join.

Dissenting opinion filed by Circuit Judge REYNA, in which 

Circuit Judge NEWMAN joins.

CHEN, Circuit Judge.

This case involves differential payment programs established by the Office of Personnel Management (OPM), 

via regulations promulgated pursuant to 5 U.S.C. 

§§ 5545(d) and 5343(c)(4), to provide hazardous duty and 

environmental differential pay to federal employees. 

Plaintiffs-Appellants appeal from a Court of Federal 

Claims (Claims Court) decision dismissing their broad 

claims for hazardous duty and environmental differential 

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ADAMS v. US 3

pay (along with related overtime, interest, and attorneys’ 

fees and costs) based on allegations that they “work[ed]

with or in close proximity to objects, surfaces, and/or individuals infected with” the novel coronavirus (COVID-19)1

“without sufficient protective devices.” See Adams v. 

United States, 152 Fed. Cl. 350, 351–52, 355 (2021). This

appeal was initially argued before a panel of the court on 

October 6, 2021. Prior to disposition by the panel, however, 

we sua sponte ordered en banc review. Adams v. United 

States, 38 F.4th 1040, 1041 (Fed. Cir. 2022). Oral argument before the en banc court was held on December 9, 

2022. 

COVID-19 is a serious national and international 

health concern, and the potential ramifications of this case 

are far-reaching and cut across the entire federal workforce. Appellants’ asserted basis for hazardous duty and 

environmental differential pay might encompass many federal employees in federal workplaces where ambient exposure to COVID-19 might occur.2 See J.A. 29–30 ¶¶ 25, 30. 

1 For clarity and consistency with the Claims Court’s 

decision, “COVID-19” is used herein to encompass both the 

novel coronavirus, SARS-CoV-2, and the disease caused by 

that novel coronavirus, COVID-19. See Adams, 152 Fed.

Cl. at 351 n.1.

2 For example, plaintiffs in the class-action suit 

Braswell v. United States seek hazardous duty pay, environmental differential pay, and overtime pay based on substantially similar allegations as raised here. See Second 

Amended Complaint ¶¶ 162–65, 176–178, Braswell, No. 

1:20-cv-00359, (Fed. Cl. Mar. 2, 2022) ECF No. 27-1 (seeking hazardous duty and environmental differential pay for 

“perform[ing] work with or in close proximity to objects, 

surfaces, and/or individuals infected with COVID-19 without sufficient protective devices”); see also Appellee’s En 

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4 ADAMS v. US

Appellants accept that, in order for them to prevail, it is 

not enough that COVID-19 can readily be characterized as 

“unusual”—one of the requirements of the statutory provisions at issue. Rather, recognizing Congress’s commitment 

of the necessary judgments to OPM, they agree that their 

case depends on whether their allegations come within 

OPM’s existing regulations, which Appellants do not challenge and which delimit particular situations in which federal employees are entitled to hazardous duty and 

environmental differential payments. We conclude that 

OPM simply has not addressed contagious-disease transmission (e.g., human-to-human, or through human-contaminated intermediary objects or surfaces) outside two 

settings not present here—e.g., certain situations within 

laboratories and a jungle-work situation. Although OPM 

might well be able to provide for differential pay based on 

COVID-19 in various workplace settings, it has not to date 

adopted regulations that do so. Under existing regulations, 

we affirm.

Banc Br., at viii (Statement of Related Cases). Braswell’s 

original complaint included plaintiffs from the Bureau of 

Prisons, Department of Agriculture, and the Department 

of Veterans Affairs. Complaint ¶¶ 4–8, Braswell (Fed. Cl. 

Mar. 27, 2020), ECF No. 1. An amended complaint subsequently added plaintiffs from the Department of Labor, Social Security Administration, Federal Grain Inspection 

Service, multiple Department of Defense components, and 

multiple Department of Homeland Security components. 

Amended Complaint ¶¶ 10, 12–14, 16–24, Braswell (July 

22, 2020), ECF No. 11. The Claims Court partially stayed 

Braswell pending the disposition of this appeal. Order at 

5, Braswell (Fed. Cl. Aug. 20, 2021), ECF No. 25.

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ADAMS v. US 5

BACKGROUND

I. Statutory and Regulatory Background

At issue in this case are statutes and regulations related to (1) a hazardous duty pay program, and (2) an environmental differential pay program. In 1966, Congress 

authorized OPM’s predecessor, the U.S. Civil Service Commission, to provide additional compensation at fixed rates 

(pay differentials) to salaried, General Schedule employees 

“for duty involving unusual physical hardship or hazard.” 

Adair v. United States, 497 F.3d 1244, 1252–54 (Fed. Cir. 

2007); see also Pub. L. No. 89-512, § 1, 80 Stat. 318, 318 

(1966) (codified as amended at 5 U.S.C. § 5545(d)). At the 

time, there was no mechanism for compensating General 

Schedule employees who performed assignments involving 

unusual physical hardships or hazards outside those employees’ job classification. See Adair, 497 F.3d at 1253 (citing H.R. Rep. No. 89-31, 1st Sess., at 2 (1965)). The 

hazardous duty pay program was thus intended to serve as 

a gap-filling measure to provide “additional remuneration 

to [an] employee asked to take unusual risks not normally 

associated with [their] occupation and for which added 

compensation is not otherwise provided[.]” Id. at 1254 

(quoting H.R. Rep. No. 89-31 at 4). 

In 1972, Congress established a Federal Wage System 

applicable to a different class of federal employees and authorized OPM to pay environmental differentials to those 

employees for “duty involving unusually severe working 

conditions or unusually severe hazards[.]” Pub. L. No. 

92-392, § 5343(c)(4), 86 Stat. 564, 567 (1972) (codified as 

amended at 5 U.S.C. § 5343(c)(4)). 

There is no dispute that Congress did not expressly define “duty involving unusual physical hardship or hazard,”

see 5 U.S.C. § 5545(d), nor “duty involving unusually severe 

working conditions or unusually severe hazards,” see id.

§ 5343(c)(4). Congress instead directed OPM to establish 

pay differential schedules for such duties. Id. § 5545(d)

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6 ADAMS v. US

(“The Office shall establish a schedule or schedules of pay 

differentials for duty involving unusual physical hardship 

or hazard . . . .”); id. § 5343(c)(4) (“The Office of Personnel 

Management, by regulation, shall prescribe practices and 

procedures for . . . administering the prevailing rate system[, and t]he regulations shall provide . . . for proper differentials, as determined by the Office, for duty involving 

unusually severe working conditions or unusually severe 

hazards . . . .”). Pursuant to congressional delegation, 

OPM (and its predecessor) promulgated 5 C.F.R. § 550.901 

et seq., covering hazardous duty pay, and 5 C.F.R. 

§ 532.501 et seq., covering environmental differential pay. 

We previously determined that OPM’s regulations are reasonable in view of their authorizing statutes and the legislative histories therefor. See Adair, 497 F.3d at 1255, 1257. 

Neither party disputes this. See Appellants’ Br. 17–21; Appellee’s Br. 20–21. 

OPM’s regulations define “hazardous duty” as “duty 

performed under circumstances in which an accident could 

result in serious injury or death, such as duty performed 

on a high structure where protective facilities are not used 

or on an open structure where adverse conditions such as 

darkness, lightning, steady rain, or high wind velocity exist.”3 5 C.F.R. § 550.902. In other words, an employee performs a hazardous duty where there is a recognized danger 

or risk that the employee would suffer a serious injury or 

death if an accident were to occur. In addition to various 

examples of such duties that could give rise to a serious 

accident provided by OPM’s “hazardous duty” definition, 

OPM has promulgated specific schedules, pursuant to Congress’s statutory mandate, that itemize several dozen

3 Appellants only allege that they are entitled to hazardous duty pay pursuant to OPM’s hazardous duty pay 

schedule. Appellants do not seek payments for duties involving physical hardship. See Appellants’ Br. 36–39.

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ADAMS v. US 7

inherently dangerous, specific duties approved for hazardous duty and environmental differential pay. 

Specifically, “[a]n agency shall pay the hazard pay differential listed in appendix A of this subpart to an employee who is assigned to and performs any duty specified 

in appendix A,” provided that the hazardous duty has not 

been accounted for in the employee’s job description. See 5 

C.F.R. § 550.904(a). Appendix A is a table titled “Schedule 

of Pay Differentials Authorized for Hazardous Duty Pay” 

that lists various duties and their corresponding pay differential. 5 C.F.R., Pt. 550, Subpt. I, Appx. A (HDP Schedule). 

Similarly, OPM’s environmental differential pay regulations specify that “an employee shall be paid an environmental differential when exposed to a working condition or 

hazard that falls within one of the categories approved by 

[OPM],” 5 C.F.R. § 532.511(a)(1), and as set forth in OPM’s 

Schedule of Environmental Differentials, see 5 C.F.R., Pt. 

532, Subpt. E, Appx. A (EDP Schedule); see also 5 C.F.R. 

§ 532.511(d). Like the HDP Schedule, the EDP Schedule 

lists various degrees of hazards, hardships, and unusual 

conditions and their corresponding pay differential. See

EDP Schedule. 

The HDP Schedule was first promulgated in 1969, and 

certain compensable categories of the EDP Schedule were

first promulgated in 1970. See Pay Differentials for Irregular or Intermittent Hazardous Duty, 34 Fed. Reg. 11,083, 

11,083–84 (July 1, 1969) (codified at HDP Schedule); Prevailing Rate Systems, 55 Fed. Reg. 46,140, 46,180–85 (Nov. 

1, 1990) (codified at EDP Schedule). The schedules have 

been amended over time to include additional duties that 

OPM approved for differential pay. For example, OPM 

amended the HDP Schedule in 1990 to add a Tropical Jungle Duty category that authorizes hazardous duty pay for 

“employees who are working in undeveloped tropical jungle 

regions outside the continental United States and who are 

exposed to . . . unusual hazards.” See Pay Differentials, 

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8 ADAMS v. US

55 Fed. Reg. 1,353, 1,353–54 (Jan. 16, 1990). OPM also 

amended the HDP and EDP Schedules in 1993 and 1975, 

respectively, to authorize differential pay for employees

whose assigned duties exposed them to asbestos fibers at 

concentrations that could potentially cause illness or injury. See Pay Administration (General); Hazard Pay Differentials, 58 Fed. Reg. 32,048, 32,048–51 (June 8, 1993) 

(indicating that an Asbestos category will be codified in the 

HDP Schedule); see also Prevailing Rate Systems, 55 Fed. 

Reg. at 46,184 (referencing an Asbestos category for which 

environmental differential pay was available as of March 

9, 1975). In total, to date, the HDP and EDP Schedules 

respectively identify 57 and 35 specific duties—e.g., involving hazardous materials, hazardous weather or terrain, 

physiological hazards, flight-related hazards, etc.—that 

are currently entitled to differential pay.

Relevant here, the HDP Schedule establishes a 25-percent pay differential for “work with or in close proximity to” 

“virulent biologicals,” which are hazardous agents defined 

as “[m]aterials of micro-organic nature which when introduced into the body are likely to cause serious disease or 

fatality and for which protective devices do not afford complete protection” (Virulent Biologicals category). HDP 

Schedule. The EDP Schedule also establishes pay differentials for “working with or in close proximity to” “microorganisms” (Micro-organisms category) at two different 

levels of risk—(1) those that pose a “high degree hazard”

and “involve[] potential personal injury such as death, or 

temporary, partial, or complete loss of faculties or ability to 

work due to acute, prolonged, or chronic disease” (high risk 

subcategory); and (2) those that pose a “low degree hazard”

(low risk subcategory). Id. The high risk subcategory covers “work situations wherein the use of safety devices and 

equipment, medical prophylactic procedures such as vaccines . . . and other safety measures do not exist or have 

been developed but have not practically eliminated the potential for . . . personal injury.” Id. The EDP Schedule 

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ADAMS v. US 9

provides two examples for understanding the scope of the

high risk subcategory: 

- Direct contact with primary containers of organisms pathogenic for man such as culture flasks, culture test tubes, hypodermic syringes and similar 

instruments, and biopsy and autopsy material. Operating or maintaining equipment in biological experimentation or production

- Cultivating virulent organisms on artificial media, including embryonated hen's eggs and tissue 

cultures where inoculation or harvesting of living 

organisms is involved for production of vaccines, 

toxides, etc., or for sources of material for research 

investigations such as antigenic analysis and 

chemical analysis

Id. The low risk subcategory covers “situations for which 

the nature of the work does not require the individual to be 

in direct contact with primary containers of organisms 

pathogenic for man. . . .” Id. 

II. Procedural Background

Appellants are current and former employees of the 

United States Federal Bureau of Prisons working at Federal Correctional Institute Danbury (FCI Danbury) in Danbury, Connecticut. FCI Danbury is a low-security federal 

correctional institution which houses over 650 inmates. 

These current and former employees are either General 

Schedule employees eligible for hazardous duty pay pursuant to 5 U.S.C. § 5545(d), or are employees under the Federal Wage System eligible for environmental differential 

pay pursuant to 5 U.S.C. § 5343(c)(4). 

On June 26, 2020, Appellants initiated this action

against the government, alleging that they are entitled to 

hazardous duty and environmental differential pay due to 

their “work [with] or in close proximity to objects, surfaces, 

and/or individuals infected with COVID-19 without 

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10 ADAMS v. US

sufficient protective devices,” which resulted in them being 

exposed to COVID-19. J.A. 30–35 ¶¶ 35–38, 45–51. There 

is no dispute that COVID-19 is a communicable disease 

that can cause injury. See Appellee’s En Banc Br. 24; Appellants’ En Banc Reply Br. 8. Appellants allege that 

(1) COVID-19 is easily transmissible in the workplace 

through “objects, surfaces, and/or individuals,” (2) inmates 

and staff have contracted COVID-19, and (3) by reporting 

to the facility during the COVID-19 pandemic where they 

may encounter infected inmates or staff, Appellants “work 

with or in close proximity to” “virulent biologicals” and “micro-organisms.” J.A. 27–30 ¶¶ 17, 21–24, 30. Appellants 

also sought deficiencies in overtime pay, under the Fair Labor Standards Act (FLSA), “caused by the failure of the 

agency to include hazardous duty and environmental pay 

differential payments” in their overtime calculations. 

J.A. 34–35 ¶ 57. 

On February 5, 2021, the Claims Court granted the 

government’s motion to dismiss Appellants’ complaint for 

failure to state a claim upon which relief can be granted. 

See Adams, 152 Fed. Cl. at 351 (citing Rule 12(b)(6) of the 

United States Court of Federal Claims). The Claims Court

determined that Appellants failed to state a claim for hazardous duty pay because neither 5 U.S.C. § 5545(d) nor 

OPM’s implementing regulations provide hazardous duty 

pay for workplace exposure to objects, surfaces, and/or individuals infected with COVID-19. Adams, 152 Fed. Cl. at

355 (citing Adair, 497 F.3d at 1254, 1255). The Claims 

Court also determined that our prior construction of the

regulatory phrase “work[] with or in close proximity to” 

foreclosed Appellants’ claim for environmental differential 

pay based on alleged “work[] with or in close proximity to” 

“micro-organisms.” Id. at 356–57 (citing Adair, 497 F.3d at 

1257–58). Finally, the Claims Court determined that Appellants’ FLSA claims are derivative of their hazardous 

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ADAMS v. US 11

duty and environmental differential pay claims and, therefore, barred.4 Id. at 357. 

Appellants timely appealed, and we have jurisdiction 

under 28 U.S.C. § 1295(a)(3).

STANDARD OF REVIEW

This Court reviews de novo the Claims Court’s dismissal of a complaint for failure to state a claim upon which 

relief can be granted. Creative Mgmt. Servs., LLC v. United 

States, 989 F.3d 955, 961 (Fed. Cir. 2021). Moreover, because we review judgments, not opinions, see Mingus Constructors, Inc. v. United States, 812 F.2d 1387, 1392 (Fed. 

Cir. 1987), we “may affirm the [trial] court on a ground not 

selected by the [trial] judge so long as the record fairly supports such an alternative disposition of the issue,” Banner 

v. United States, 238 F.3d 1348, 1355 (Fed. Cir. 2001) (citation omitted).

DISCUSSION

Neither party disputes that Congress did not define the 

scope and meaning of “unusual physical hardship or hazard” entitled to hazardous duty pay or “unusually severe 

hazards” entitled to environmental differential pay. See

Appellants’ Br. 26; Appellee’s Br. 20; see also 5 U.S.C. 

§§ 5343(c)(4), 5545(d). Both parties agree that Congress 

delegated to OPM the authority to determine the types of 

duties that are entitled to such pay differentials, and neither side challenges the validity of OPM’s existing regulations. See Appellants’ Br. 16–17, 26; Appellee’s Br. 5–6, 

8–12. So regardless of whether Appellant’s allegations 

could be plausibly understood as describing an “unusual 

physical hardship or hazard” or “unusually severe 

4 Appellants concede that their FLSA claims are derivative of their claims for hazardous duty and environmental differential pay. Appellants’ Br. 4 n.2.

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12 ADAMS v. US

hazards,” only employees who meet OPM’s regulatory requirements are entitled to hazardous duty or environmental differential pay. See 5 U.S.C. § 5545(d) (“Under such 

regulations as [OPM] may prescribe . . . an employee . . . is 

entitled to be paid the appropriate differential . . . .”) (emphasis added); 5 U.S.C. § 5343(c)(4) (OPM regulations 

“shall provide . . . for proper differentials, as determined by 

the Office, for duty involving unusually severe working conditions or unusually severe hazards”) (emphasis added). 

Indeed, Appellants concede that their HDP and EDP 

claims fail if they do not fall under the HDP Schedule’s Virulent Biologicals category or the EDP Schedule’s Micro-organisms category. See En Banc Oral Arg. at 3:12–3:35. 

Thus, the only issue is whether Appellants’ theory of recovery satisfies one of OPM’s specifically delineated categories 

for hazardous duty or environmental differential pay.5

Appellants argue that they stated viable claims for environmental differential pay involving “micro-organisms” 

and hazardous duty pay involving “virulent biologicals” because they “were assigned to work with or in close proximity to objects, surfaces, and/or individuals (including 

inmates and coworkers) who were infected with 

COVID-19.” Appellants’ Br. 17–21; see also Appellants’ Reply Br. 20–21; Appellants’ En Banc Reply Br. 21 (arguing 

5 Although the dissent focuses on whether Appellants adequately plead the “unusually” hazardous requirement of the HDP and EDP statutes, Dissent Op. at 3–8,

Appellants do not argue that they are entitled to hazardous 

duty or environmental differential pay based solely on 5 

U.S.C. §§ 5343(d) and 5545(d) for the reason that

COVID-19 in the workplace could be understood as a “hazard” that is “unusual” or “unusually severe,” nor do Appellants argue that OPM is required to promulgate 

regulations that cover ambient exposure to COVID-19 in 

the workplace. See En Banc Oral Arg. at 2:28–3:35. 

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ADAMS v. US 13

that “it is the circumstances and surroundings that make 

the duties hazardous, not necessarily the duty itself”). We 

disagree with Appellants, based on the text, structure, and 

history of the Schedules, as well as on our decision in 

Adair.

As an initial matter, neither party argues that “work[]

with or in close proximity to” should be interpreted differently with respect to the HDP Schedule’s Virulent Biologicals category and the EDP Schedule’s Micro-organisms

category. Nothing in the language of HDP or EDP Schedules persuades us otherwise. Moreover, our analysis in 

Adair, where we reviewed a closely analogous provision in 

the EDP Schedule covering “[w]orking with or in close 

proximity to poisons (toxic chemicals)” is informative as to 

the scope of the HDP and EDP Schedule’s Virulent Biologicals and Micro-organisms categories at issue here. See 497 

F.3d at 1255–58. Adair involved exposure to second-hand 

tobacco smoke in a prison environment, which the plaintiffs alleged was a “toxic chemical” covered by the Toxic 

Chemicals category of OPM’s HDP and EDP Schedules. 

497 F.3d at 1255–58. Similar to the structure of the Microorganisms category, the EDP Schedule describes examples 

of high degree toxic chemical hazards (high risk subcategory), including handling and storing toxic chemical 

agents, visually examining chemical agents, transferring 

chemical agents between containers, etc. See EDP Schedule. For low degree toxic chemical hazards (low risk subcategory), on the other hand, the EDP Schedule states that 

“the nature of the work does not require the individual to 

be in as direct contact with, or exposure to, the more toxic 

agents.” Id. We therefore determined that “one key difference” between the high and low risk subcategories for 

“toxic chemicals” is that “the employee in the low [risk 

sub]category can be many degrees removed from the toxic 

agent.” Adair, 497 F.3d at 1257. 

Considering the high and low risk Toxic Chemicals 

subcategories together, we concluded that “[a]lthough the 

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14 ADAMS v. US

examples are not exhaustive, they all describe scenarios 

where the job assignment requires directly or indirectly 

working with toxic chemicals or containers that hold toxic 

chemicals as part of a job assignment.” Id. at 1258. We 

further explained that the EDP Schedule’s Toxic Chemicals category is not so broad that they would “cover situations in which employees work with inmates who 

incidentally smoke, for there is no work ‘with’ [second-hand 

smoke] in th[at] context.” See id. (emphasis added). For 

these reasons, among others, we affirmed the dismissal of 

the complaint for failure to state a claim.

Adair is instructive because just as the EDP Schedule’s 

Toxic Chemicals category requires “working with or in 

close proximity to” “toxic chemicals,” EDP Schedule’s Micro-organisms category requires “working with or in close 

proximity to” “micro-organisms.” Like the Toxic Chemical 

category’s examples considered in Adair, the examples

listed in the EDP Schedule’s high risk Micro-organisms 

subcategory require (1) “[d]irect contact with primary containers of organisms pathogenic for man . . . ,” (2) “[o]perating or maintaining equipment in biological 

experimentation or production,” or (3) “[c]ultivating virulent organisms on artificial media.” EDP Schedule. These 

examples do not cover situations in which employees working with inmates face contagious-disease transmission via 

ambient exposure to COVID-19 in the workplace by way of 

infected humans, for “there is no work ‘with’ [COVID-19] 

in this context.” See Adair, 497 F.3d at 1258. And we agree 

with the Claims Court that Appellants’ alleged duties are 

not analogous to the class of exemplary duties provided in 

the high risk micro-organism subcategory of the EDP 

Schedule. See Adams, 152 Fed. Cl. at 356. Like the high 

risk Toxic Chemicals subcategory we analyzed in Adair, 

the high risk Micro-organisms subcategory contemplates 

directly working with micro-organisms or containers holding micro-organisms. 

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ADAMS v. US 15

In addition, tracking the same high/low risk structural 

relationship for Toxic Chemicals, the EDP Schedule defines the low risk Micro-organisms subcategory in direct relation to a specific example in the high risk micro-organism 

subcategory—i.e., “does not require” “direct contact with 

primary containers of organisms pathogenic for man, such 

as culture flasks, culture test tubes, hypodermic syringes 

and similar instruments, and biopsy and autopsy material.” Compare EDP Schedule at Micro-organisms – low 

degree hazard (emphasis added), with id. at Micro-organisms – high degree hazard, first example. There is thus a 

strong inference that the low risk Micro-organisms subcategory requires that an employee’s assigned duty must at 

least involve working indirectly with the primary containers of pathogenic organisms identified in the high risk Micro-organisms subcategory. This inference is consistent 

with the language and overall design of the EDP Schedule, 

and, in particular, our conclusion in Adair for the similarlydefined low risk Toxic Chemicals subcategory, which likewise “does not require the [employee] to be in as direct contact with, or exposure to, the [toxic chemicals]” and which 

we concluded requires “indirectly working with toxic chemicals or containers that hold toxic chemicals as part of a job 

assignment.” See Adair, 497 F.3d at 1257–58; see also 

K Mart Corp. v. Cartier, Inc., 486 U.S. 281, 291 (1988) (“In 

ascertaining the plain meaning of the statute, the court 

must look to the particular statutory language at issue, as 

well as the language and design of the statute as a whole.”

(citation omitted)); Green v. Brennan, 578 U.S. 547, 553–54 

(2016) (applying statutory interpretation canons to regulations). 

Although the Micro-organisms category’s examples are 

not exhaustive, like Adair’s Toxic Chemicals category, they 

uniformly reflect the nature and locus of work contemplated in the Micro-organisms category—i.e., they require 

working directly or indirectly with “micro-organisms which 

involves potential personal injury such as death, or 

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16 ADAMS v. US

temporary, partial, or complete loss of faculties or ability to 

work due to acute, prolonged, or chronic disease” as part of 

a job assignment. See Adair, 497 F.3d at 1258 (concluding 

that “working with or in close proximity to” “toxic chemicals” involves “directly or indirectly working with toxic 

chemicals . . . as part of a job assignment,” as opposed to 

“situations in which known hazards . . . are common or 

ubiquitous in the ambient work environment”). Moreover,

the substantial relationship between the EDP Schedules’ 

Toxic Chemical category that we considered in Adair6 and 

the Micro-organisms category here—i.e., their shared usage of the “work[] with or in close proximity to” language 

and specific examples focused on working directly or indirectly with the hazardous material—implicates the rule of 

“construction that identical words used in different parts of 

the same act [or provision] are intended to have the same 

meaning.” See Sullivan v. Stroop, 496 U.S. 478, 484 (1990) 

(quoting Sorenson v. Sec’y of Treasury, 475 U.S. 851, 860 

(1986)).7

Appellants’ theory that “primary containers,” as that 

term is used in the EDP Schedule, includes infected humans because humans are primary carriers for incubating 

and spreading COVID-19 is unconvincing. See Appellants’ 

En Banc Br. 38–42; Appellants’ En Banc Reply Br. 25–27; 

Appellee’s En Banc Br. 53–57. The EDP Schedule’s listed

examples of “primary containers” uniformly reflect objects 

of research or experimentation. See EDP Schedule (listing 

6 Appellants argue that “Adair is distinguishable 

from this case in many ways.” See Appellants’ En Banc 

Reply Br. 27; see also Appellants’ En Banc Br. 19, 22, 

30–31. Appellants, however, do not seek to overturn Adair. 

See Appellants’ En Banc Reply Br. 27.

7 While Sullivan dealt with a rule of statutory interpretation, the same approach is taken to interpret regulations. See Green, 578 U.S. at 553–54.

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ADAMS v. US 17

culture flasks, culture test tubes, hypodermic syringes and 

similar instruments, and biopsy and autopsy material). 

Given that nothing in the regulatory history suggests such 

an unusual understanding of living humans as containers, 

we think it would be an unreasonable stretch of the term 

“containers” to include infected humans. Put simply, the 

relevant indicia in the EDP Schedule, coupled with our reasoning in Adair for the same “work[] with or in close proximity to” language used in the EDP Schedule’s analogous 

Toxic Chemicals category, compels the conclusion that the 

EDP Schedule’s Micro-organisms category requires working directly or indirectly with pathogenic micro-organisms 

themselves.

The HDP Schedule does not expressly recite examples

illustrating when an employee “work[s] with or in close 

proximity to . . . [v]irulent biologicals,” but historical, contemporaneous guidance from OPM provides several exemplary duties that are very similar to the above-discussed 

examples listed in the EDP Schedule’s high risk Micro-organisms subcategory:

• Operating or maintaining equipment in biological experimentation or production.

• Cleaning and sterilization of vessels and equipment contaminated with virulent micro-organisms.

• Caring for or handling disease-contaminated experimental animals in biological experimentation and production in medical laboratories, the 

primary mission of which is research and development not directly associated with patient care. 

This includes manipulating animals infected 

with virulent organisms, such as inoculating of 

animals, obtaining blood and tissue specimens, 

and disposing of excreta and contaminated bedding and cages.

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18 ADAMS v. US

• Cultivating virulent organisms on artificial mediums, including embryonated hen’s eggs and 

tissue cultures where inoculation or harvesting 

of living organisms is involved for production of 

vaccines, toxides, etc., or for sources of material 

for research investigations such as antigenic 

analysis and chemical analysis.

Background Info. on Appx. A to Part 550, Fed. Per. Manual, Supp. 990-2 § 550-E-4, 1973 WL 151518 (1973) (HDP 

Supplement). These examples likewise do not cover situations in which employees working with inmates face contagious-disease transmission via ambient exposure to 

COVID-19 in the workplace, for “there is no work ‘with’ 

[COVID-19] in this context.” See Adair, 497 F.3d at 1258. 

Although the HDP Supplement comes from a Federal 

Personnel Manual that is no longer in force, we have continued to regard the Federal Personnel Manual as “a valuable resource for construing regulations that were 

promulgated or were in effect” before it was discontinued

in 1993. See Schmidt v. Dep’t of Interior, 153 F.3d 1348, 

1353 n.4 (Fed. Cir. 1998). Because the Virulent Biologicals 

category was first promulgated in 1969 and has not been 

amended since then, see 34 Fed. Reg. at 11,083–84, the 

HDP Supplement “serve[s] as an aid to agencies in determining what situations a hazardous duty described in [the 

HDP Schedule] covers.” See HDP Supplement at 1. The 

HDP Supplement’s examples for “work[ing] with or in close 

proximity to . . . [v]irulent biologicals” uniformly reflect 

“the nature of the hazard the differential is intended to 

compensate”—i.e., assignments that involve directly or indirectly working with a virulent biological itself rather 

than ambient exposure to a virulent biological in the workplace due to transmission by infected humans.

Additionally, it does not appear that OPM intended 

that “work[] with or in close proximity to” “virulent biologicals” or “micro-organisms” in the HDP and EDP 

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ADAMS v. US 19

Schedules, respectively, would encompass contagious-disease transmission via ambient exposure not resulting from 

working directly or indirectly with the virulent biological 

or pathogenic micro-organism because the schedules use, 

for other hazardous material categories, specific language 

when indicating that ambient exposure to hazardous materials is entitled to differential pay. For example, the HDP 

Schedule uses clear language in the Tropical Jungle Duty 

category indicating that a possibility of exposure to infectious diseases in a jungle work environment is entitled to 

differential pay. See HDP Schedule (covering “[w]ork outdoors in undeveloped jungle regions outside the continental 

United States . . . . involv[ing] . . . [a]n unusual danger of 

serious injury or illness due to . . . [k]nown exposure to serious disease for which adequate protection cannot be provided” (emphasis added)). As such, the HDP Schedule 

covers ambient exposure to infectious diseases that may be 

inherently present in a jungle environment. In contrast, 

the Virulent Biologicals and Micro-organisms categories 

lack any corresponding description of ambient exposure in 

a workplace to those hazardous materials from outside 

sources; they instead are directed to working directly or indirectly with the hazardous material itself.8

In addition to Tropical Jungle Duty, OPM also added

an Asbestos category to both the HDP and EDP Schedules 

8 We disagree with the dissent’s view that government’s counsel made concessions during the en banc oral 

argument that “nullify” our interpretation of the regulations. Dissent Op. at 9–11. The government counsel’s 

vague, open-ended answers are a weak basis for declining 

to give the Virulent Biologicals and Micro-organisms categories their best interpretation within the framework of 

the HDP and EDP Schedules. Moreover, the government 

has not argued in this case for any form of deference for its 

reading of OPM’s regulations.

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20 ADAMS v. US

to compensate federal employees who are required to work 

“in an area where airborne concentrations of asbestos fibers may expose them to potential illness or injury.” See

Pay Differentials, 55 Fed. Reg. 31,190, 31,190 (Aug. 1, 

1990) (Proposed Rule); see also Prevailing Rate Systems, 55 

Fed. Reg. at 46,184 (referencing an Asbestos category that 

was codified into the EDP Schedule on March 9, 1975). Due 

to concern that OPM’s proposed Asbestos category for the 

HDP Schedule lacked a “clear definition of ‘exposure’” and 

was “too permissive [such] that agencies would end up paying almost all . . . employees who could conceivably have 

been exposed to any level of asbestos,” OPM incorporated a 

reference to the Occupational Safety and Health Administration’s permissible exposure limit standard into the final Asbestos category and explained that “mere existence 

of airborne concentrations of asbestos fibers in a particular 

work environment is not enough, by itself, to warrant [hazardous duty pay].” Pay Administration (General); Hazard 

Pay Differentials, 58 Fed. Reg. 32,048, 32,048 (codified at 

HDP Schedule). 

The HDP Schedule’s Asbestos category thus includes 

express language covering “[s]ignificant risk of exposure to 

airborne concentrations of asbestos fibers in excess of the 

permissible exposure limits (PELS) in the standard for asbestos provided in title 29, Code of Federal Regulations, 

§§ 1910.1001 or 1926.58, when the risk of exposure is directly connected with the performance of assigned duties.” 

HDP Schedule; see also EDP Schedule (“Asbestos. Working 

in an area where airborne concentrations of asbestos fibers 

may expose employees to potential illness or injury. This 

differential will be determined by applying occupational 

safety and health standards consistent with the permissible exposure limit promulgated by the Secretary of Labor 

under the Occupational Safety and Health Act of 1970 as 

published in title 29, Code of Federal Regulations, 

§§ 1910.1001 or 1926.1101.”). Thus, for employees who are 

required to do their work in an environment with a 

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ADAMS v. US 21

hazardous, airborne concentration level of asbestos fibers, 

OPM specifically created a category to compensate employees who bear the risk of performing assigned duties in such 

a hazardous environment, including employees who did not 

work with the asbestos material itself. See HDP Schedule 

(Asbestos category); see also EDP Schedule (Asbestos category).

As evident by OPM’s inclusion of language covering 

general, ambient exposure in the Tropical Jungle Duty and 

Asbestos categories, OPM knows how to distinguish categories involving ambient exposure to hazardous materials 

from categories involving exposure to the hazardous materials themselves resulting from work with those materials 

(e.g., toxic chemicals, unstable explosives, virulent biologicals, etc.). The logical conclusion, then, is that OPM intended the Virulent Biologicals and Micro-organisms

categories to apply only when the employee is working with 

or near a virulent biological or micro-organism itself, not 

doing any task that might incur exposure to a virulent biological or micro-organism generally. If OPM intended for 

the HDP Schedule’s “virulent biologicals” category or the 

EDP Schedule’s “micro-organisms” category to provide differential pay for ambient exposure to dangerous, communicable diseases, it certainly “knew how to say so.” See Rubin 

v. Islamic Republic of Iran, 138 S. Ct. 816, 826 (2018) (discussing congressional intent); Green, 578 U.S. at 553–54 

(applying statutory interpretation canons to regulations). 

So even though the HDP Schedule’s Asbestos category includes the same “work[] with or in close proximity to” language present in, e.g., the Toxic Chemicals or Virulent 

Biologicals categories, the additional “risk of exposure” language and concentration standard present in the Asbestos 

category indicates that the Asbestos category is not as limited as the other categories. In other words, because OPM 

did not include any “risk of exposure” language in the Virulent Biologicals or Micro-organism categories as it did for 

other categories, “work[] with or in close proximity to” 

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22 ADAMS v. US

“virulent biologicals” or “micro-organisms” in the context of 

the HDP and EDP Schedules cannot reasonably encompass 

duties that involve assignments unrelated to working with 

or near virulent biologicals or micro-organisms themselves.

That said, both Appellants and the government argue 

that OPM’s March 7, 2020, Memorandum entitled “Questions and Answers on Human Resources Flexibilities and 

Authorities for Coronavirus Disease 2019 (COVID-19)”

(OPM Memo) is instructive and favorable to their respective positions. See Appellants’ Br. 39 n.9; Appellants En 

Banc Br. 31–32; Appellee’s Br. 37 n.7; Appellee’s En Banc 

Br. 41. We determine, however, that the OPM Memo does 

not take any definitive position as to whether the HDP or 

EDP Schedules (a) cover contagious-disease transmission 

via ambient exposure to virulent biologicals due to transmission by infected humans, or (b) require directly or indirectly working with virulent biologicals or micro-organisms 

themselves. See OPM Memo at 12 (“Agencies may pay a

hazard pay differential . . . for exposure to ‘virulent biologicals’ only when the risk of exposure is directly associated 

with the performance of assigned duties.”); but see id. at 

12–13 (explaining that “hazard pay differential cannot be 

paid to an employee who may come in contact with the 

[COVID-19] virus or another similar virus through incidental exposure to the public or other employees who are 

ill,” “employees may not receive an environmental differential for incidental exposure to the pandemic COVID-19,” 

and “[t]here is no authority within the hazardous duty pay 

or environmental differential statutes to pay for potential

exposure” (first and second emphases added)). 

In our view, the OPM Memo does not speak with one

clear, consistent voice that conflicts with the overall design 

of the HDP and EDP Schedules—as indicated by OPM’s 

contemporaneously-specified duty-examples in the EDP 

Schedule and the Federal Personnel Manual associated 

with the HDP Schedule—to require work directly or indirectly with COVID-19 itself. Moreover, the OPM Memo did 

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ADAMS v. US 23

not engage in any interpretive analysis of the relevant 

“work with or in close proximity” language, let alone even 

suggest that it provides a regulatory interpretation of the 

HDP and EDP Schedules. And because it quickly issued at 

the very start of a pandemic emergency, affording it deference would raise concerns about the use of informal, interpretive announcements instead of formal rulemaking to 

make significant regulatory changes. See Kisor v. Wilkie, 

139 S. Ct. 2400, 2416 (2019) (explaining Auer deference is 

not warranted when a “regulatory interpretation” is 

“merely ad hoc statement[s]” rather than the “agency’s ‘authoritative’ or ‘official position’”).

Because Appellants read “work[ing] with or in close 

proximity to” “virulent biologicals” or “micro-organisms” 

broadly to encompass contagious-disease transmission via 

ambient exposure and have not alleged that they worked 

directly or indirectly with COVID-19 itself, they have not

sufficiently pled claims for hazardous duty and environmental differential pay.9 Accordingly, the Claims Court 

did not err in concluding that Appellants’ complaint failed 

to sufficiently plead claims for hazardous duty and environmental differential pay and FLSA overtime.10 

CONCLUSION

COVID-19 has undoubtedly presented a significant 

health risk to both Appellants and the general population. 

And we recognize that pandemics are historically rare. But 

the current Virulent Biologicals and Micro-organisms categories of OPM’s HDP and EDP Schedules do not cover

9 We requested briefing on the question of whether 

an amendment to the complaint should be permitted. Appellants’ supplemental briefing makes no demonstration 

that an amendment would resolve the problems with the 

original complaint.

10 See discussion supra n.4.

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24 ADAMS v. US

ambient exposure to serious, communicable diseases transmitted by infected humans. That is, the HDP and EDP 

Schedules do not provide payment in situations where an 

employee is exposed to another employee or individual carrying an infectious disease. Appellants’ theory would 

broaden the Virulent Biologicals and Micro-organisms categories to cover a significantly large number of federal employees—far more than any other category in the HDP and 

EDP Schedules. Administering such a differential pay 

would no doubt require significant amounts of investigation and review throughout the government on a workplace-to-workplace basis to determine whether a particular 

risk of ambient exposure in a given location was serious 

enough to warrant extra pay. That is not to say that such 

differential pay may not be warranted; rather, OPM’s 

schedules—as currently written—do not cover these kind 

of situations.

Federal employees who do not fit into one of the HDP 

or EDP Schedules’ categories, but whose duties nonetheless expose them to particularly heightened risk associated 

with an infectious disease circulating within the general 

population, such as COVID-19, might understandably believe that they should receive additional compensation for 

such work during a pandemic. But that is a matter for Congress or OPM to address. For example, OPM might promulgate new HDP and EDP categories or amend existing 

categories to cover human-to-human exposure to serious, 

communicable diseases while working during a pandemic.

But absent action by Congress or OPM, no judicial remedy 

is available. Accordingly, the Claims Court’s dismissal is 

affirmed.

AFFIRMED

Case: 21-1662 Document: 68 Page: 24 Filed: 02/14/2023
United States Court of Appeals 

for the Federal Circuit ______________________

CODY L. ADAMS, ROSE M. ADAMSON, JOSEPH P. 

AGIUS, DARA W. ALLICK, JENNIFER A. ANGEL, 

MICHAEL T. ANGELO, SAMMY APONTE, ALICIA 

K. AUSTIN-ZITO, LUKE M. BADARACCO, CHAD J. 

BARGSTEIN, ET AL.,

Plaintiffs-Appellants

v.

UNITED STATES,

Defendant-Appellee

______________________

2021-1662

______________________

Appeal from the United States Court of Federal Claims 

in No. 1:20-cv-00783-CFL, Senior Judge Charles F. Lettow.

______________________

REYNA, Circuit Judge, with whom NEWMAN, Circuit Judge, 

joins, dissenting.

Appellants are one hundred and eighty-eight current 

or former correctional employees of the Department of Justice, Bureau of Prisons, assigned to work at the federal 

prison located in Danbury, Connecticut.1 Appellants filed 

a complaint with the U.S. Court of Federal Claims asserting that they were entitled to additional compensation 

1 See J.A. 23; see also En Banc Op. Br. at 2.

Case: 21-1662 Document: 68 Page: 25 Filed: 02/14/2023
2 ADAMS v. US

commonly known as hazardous duty pay (“HDP”) and environmental differential pay (“EDP”), for work performed 

while exposed to COVID-19. 

The government moved to dismiss the complaint under 

Rule 12(b)(6) of the Rules of the United States Court of Federal Claims. The Court of Federal Claims granted the motion and dismissed Appellants’ complaint on grounds that 

it did not allege a plausible claim for relief. Appellants appealed the dismissal of their complaint. 

The question before us is simple: whether Appellants’ 

complaint states plausible claims for HDP and EDP. As 

shown below, the answer is “yes” for various reasons. For 

example, the Court of Federal Claims adopted overly narrow interpretations of the applicable statutes and regulations. In addition, the government made several 

admissions and concessions during the en banc argument 

that clarified in the affirmative the question of whether the 

COVID-19 pandemic gave rise to HDP and EDP. These 

admissions are consistent with extrinsic material referenced in the complaint that showed that COVID-19 exposure could give rise to HDP and EDP, and that at least one 

other department of the government was already paying 

COVID-19 related HDP and EDP compensation. Finally, 

the Court of Federal Claims departed from established law 

on Rule 12(b)(6) determinations by requiring actual proof 

of HDP and EDP eligibility—no less under its restrictive, 

overly narrow interpretations of the statute and regulations—instead of inquiring whether Appellants have alleged a plausible claim under the plain terms of the 

statutes and regulations.

Under the correct statutory and regulatory interpretations, and in view of the plain and unambiguous meaning 

of the words of the statutes, I believe that Appellants have 

pleaded sufficient facts to satisfy both key elements needed 

to plead HDP and EDP. I would thus reverse the Court of 

Federal Claims.

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ADAMS v. US 3

But there is more. In this case, experience sheds light 

on the fundamental question of whether, at the time of the 

complaint, Appellants plausibly worked “unusually” hazardous duties involving “work with or in close proximity to” 

a virulent biological or microorganism. We all have personal COVID-19 experiences. While those personal experiences are not part of the record before the court, certain 

national experiences are, as are their transformative effect. 

It is clear that the COVID-19 pandemic adversely affected our workplaces, schools, airlines, hotels, meat-packing houses, and hospitals. Schools, businesses, and 

churches closed under government order. We all went virtual because it was not safe to gather at weddings, funerals, and hospital bedsides. Even courthouses were 

momentarily shuttered on the premise that COVID-19 was 

in the streets roaring like a lion. We cannot shake off those 

experiences like dust from a rug. 

UNUSUALLY HAZARDOUS DUTY

The first element required to plead HDP and EDP is 

found in the applicable statutes. General schedule salaried 

employees qualify for HDP under 5 U.S.C. § 5545(d) when 

they are “subjected to physical hardship or hazard not usually involved in carrying out the duties of [their] position.” 

5 U.S.C. § 5545(d) (emphasis added). For waged employees, the Office of Personnel and Management (“OPM”) is 

required to establish pay differentials for duties involving 

“unusually severe hazards.” 5 U.S.C. § 5343(c)(4) (emphasis added). While the HPD and EDP statutes recite the 

“unusualness” element differently, the parties agree that 

these statutes required Appellants to allege a plausible 

claim that their duties were unusually hazardous as compared to their typical job duties. En Banc Op. Br. at 14–

15; En Banc Resp. Br. at 24–26.

The Court of Federal Claims misinterpreted this 

court’s opinion in Adair and incorrectly concluded that it 

was not unusually hazardous for Appellants “to work with 

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4 ADAMS v. US

objects, surfaces, and/or individuals infected with” COVID19.2 J.A. 27. I agree with Appellants that the trial court’s 

interpretation of the statutes was erroneous and overly 

narrow.

Neither the statutes nor the relevant regulations define “unusual.” This means that the courts should apply 

its ordinary meaning. Adair v. United States, 497 F.3d 

1244, 1253 n.2 (Fed. Cir. 2007). When the common understanding of the term “unusual” is applied, exposure to 

COVID-19 is clearly distinguishable from the issue in 

Adair—exposure to secondhand tobacco smoke at a facility 

that had long allowed inmates to smoke. Id. at 1252–56 

(finding that secondhand smoke was not an “unusual” hazard). Because smoking by both workers and prisoners was 

long permitted at correctional facilities, the typical working environment knowingly included exposure to 

secondhand smoke. Id. Conversely, it is plausible that exposure to COVID-19 was not reasonably foreseen as a 

2 The majority elected not to address whether Appellants adequately plead the “unusually” hazardous element 

because “regardless . . . only employees who meet OPM’s 

regulatory requirements are entitled to hazardous duty or 

environmental differential pay.” Maj. Op. at 11–12. This 

shortcut is mistaken. The court was required to address 

this issue because it is, for purposes of this appeal, the key 

requirement in the HDP and EDP statutes. See Yates v. 

U.S., 574 U.S. 528, 537 (2015) (explaining that statutory 

text should be interpreted by “the specific context in which 

[] language is used[] and the broader context of the statute 

as a whole”); FTC v. Mandel Bros., Inc., 359 U.S. 385, 389 

(1959) (“[O]ur task is to fit, if possible, all parts into a[] harmonious whole.”). This omission is also significant because, as discussed below, the government’s arguments 

directed to the regulations are unpersuasive. See infra

note 8 (regulations should not trump statutory command).

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ADAMS v. US 5

condition of Appellants’ work, unlike the “expected condition” of exposure to secondhand smoke in Adair. Id. at 

1253. It is also plausible that, unlike in Adair, the hazards 

created by exposure to COVID-19 created extraordinary 

risks in the performance of even Appellants’ most ordinary 

duties as federal prison employees. 

In Adair, we also recognized that when Congress last 

amended the HDP statute, it was aware of the risks posed 

by exposure to secondhand smoke but chose not to add a 

separate compensable category for such exposure. Id. at 

1254–55. Here, there is no evidence that Congress at the 

time of last amendment was aware of COVID-19 or of the 

risks associated with exposure to COVID-19.

The government asserts that COVID-19 exposure was 

not unusual, but “is inherent in the types of functions that 

[Appellants] perform” as correctional officers. En Banc 

Resp. Br. at 24. In the government’s view, “[s]tudies 

abound showing that outbreaks of communicable diseases

are not unusual in prisons.” Id. at 26–27. The government 

further argues that Appellants’ statutory construction 

would drastically expand the law and would cover “each 

new strain of the flu.” Id. at 25–26. 

In making these arguments, the government misapplies well-established pleading principles.3 To survive a 

3 The government’s argument and the Court of Federal Claims’ decision appear tainted by improper hindsight 

bias. For example, the Court of Federal Claims found that 

Appellants failed to “establish that the hazard posed by the 

virus is not adequately alleviated by protective or mechanical devices.” Adams v. U.S., 152 Fed. Cl. 350, 355 (2020)

(emphasis added, citation omitted). This is an evidentiary 

requirement that Appellants are not required to make at 

the 12(b)(6) stage. Whether such equipment was available 

and effective such that the COVID-19 working conditions 

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6 ADAMS v. US

motion to dismiss “a complaint must contain sufficient factual matter, accepted as true, to ‘state a claim to relief that 

is plausible on its face.’” Ashcroft v. Iqbal, 556 U.S. 662, 

678 (2009) (quoting Bell Atl. Corp. v. Twombly, 550 U.S. 

544, 570 (2007)); see also Cary v. United States, 552 F.3d 

1373, 1376 (Fed. Cir. 2009) (stating that RCFC 8 “does not 

require the plaintiff to set out in detail the facts upon which 

the claim is based, but enough facts to state a claim to relief 

that is plausible on its face”). For a complaint to be “plausible,” it “does not need detailed factual allegations,” but 

must simply contain enough detail “to raise a right of relief 

above the speculative level.” Twombly, 550 U.S. at 555. 

Granting a motion under RCFC 12(b)(6) requires, after accepting all well-pleaded factual allegations as true, determining that the claims are facially implausible. Lindsay v. 

United States, 295 F.3d 1252, 1257 (Fed. Cir. 2002). Here, 

the Court of Federal Claims failed to adhere to these basic 

tenets of pleading and required Appellants to prove the 

merits of their claim for relief. 

Appellants were not required to plead, as the government’s argument suggests, detailed factual allegations as 

to how their duties were “unusually” hazardous. Nor were 

they, at this stage, required to prove their case. Appellants 

were merely required to plead enough facts to state claims

were rendered not unusually hazardous is a factual issue. 

The issue before the court is not whether the hazards of 

working in a prison with COVID-19 are unusual today, but 

whether they were unusual during the period alleged in the 

complaint—which runs from the early stages of the pandemic until vaccines “became readily available to” Appellants. En Banc Oral Arg. at 4:30–5:23; J.A. 29, 33. There 

is no doubt that Appellants have sufficiently alleged that 

the COVID-19 hazards during that time period were at 

least plausibly unusual for the purposes of a 12(b)(6) motion.

Case: 21-1662 Document: 68 Page: 30 Filed: 02/14/2023
ADAMS v. US 7

that are plausible on their face, which they have done.4 

The government, to succeed on its 12(b)(6) motion, had to 

establish that Appellants’ claims were facially implausible, 

which it did not.

The courts are not heads of hardened fenceposts. The 

court can also draw—based on common knowledge about 

prisons—reasonable inferences to conclude that COVID-19 

was, at least plausibly, unusually hazardous for Appellants. See Iqbal, 556 U.S. at 679 (“[T]he reviewing court 

[can] draw on its judicial experience and common sense.”). 

It is reasonable to infer, for example, that Appellants were 

required to work in small, confined areas with poor ventilation.5 To the extent more specific allegations were required, Appellants should be allowed to amend their 

complaint. See RCFC 15(a)(2) (“The court should freely 

4 See J.A. 27–33 (pleading that “Plaintiffs have performed work with or in close proximity to objects, surfaces, 

and/or individuals infected with the novel coronavirus;” “To 

date, more than 100 employees and inmates of FCI Danbury have been confirmed to be infected with COVID-19;” 

“COVID-19 is a virus which when introduced into the body 

is likely to cause serious disease or fatality;” “Exposure to 

objects, surfaces, and/or individuals infected with COVID19 was not taken into account in the classification of plaintiffs’ positions;” and the employees lacked “sufficient protective devices”). 5 During the period in question, were there not shutdowns, courthouse and school closures, hospitals filled to 

capacity, mobile morgues, and grocery washing? Indeed, 

when this case was argued before the panel, counsel argued 

from behind plexiglass dividers, masks and social distancing were required, the number of counsel appearing for 

each side was limited, and the entire courthouse building 

was closed to the public, all for the express purpose of 

avoiding COVID-19 exposure.

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8 ADAMS v. US

give leave when justice so requires.”). In cases involving 

HDP and EDP, the court should be loath to close its doors 

too quickly. 

In sum, Appellants have adequately pleaded facts describing duties involving “unusual” hazards, satisfying the 

statutory requirement of 5 U.S.C. §§ 5545(d) and 

5343(c)(4).

WORK WITH OR IN CLOSE PROXIMITY TO

The second element required to plead HDP and EDP is 

found in the regulations. The parties agree that Appellants 

were required to plead that they worked “with or in close 

proximity to” a “virulent biological” (for HDP) or a “microorganism” (for EDP). En Banc Op. Br. at 34–35; En Banc 

Resp. Br. at 45–46. I believe that Appellants have adequately pleaded this element.

In its briefs, the government argues that the “work 

with or in close proximity to” element includes only “biological production and experimentation with pathogenic micro-organism[s].” Panel Resp. Br. at 31–32; see also id. at 

23 (arguing that the “employee’s duties [must] involve directly or indirectly working with pathogenic micro-organisms themselves, or containers that hold pathogenic microorganisms themselves, as part of a job assignment”). The 

government’s position on this point limits the regulations’

scope to cover only employees who work in a laboratory or 

perform substantially similar duties. See En Banc Resp. 

Br. at 45–46 (arguing that the “focus of the work [must be 

on] the biological material itself”). Under this theory, scuffling with an inmate who is infected with COVID-19 would 

not plausibly allege “work with or in close proximity to” the 

COVID-19 virus. To qualify, the correctional officer would 

have to scuffle with a container of COVID-19, and the scuffle would have to take place in a lab. 

At the en banc oral argument, however, the government unambiguously abandoned this position. The 

Case: 21-1662 Document: 68 Page: 32 Filed: 02/14/2023
ADAMS v. US 9

government conceded that healthcare workers treating 

COVID-19 patients could qualify for HDP and EDP. En 

Banc Oral Arg. at 44:30–47:25 (discussing potentially eligible doctors), 50:20–51:15 (conceding that a nurse working 

in a radiology unit transferred to work in a COVID-19 unit 

“would be eligible”). Counsel for the government explained: 

I think it ultimately depends on both the job description and exactly the tasks that are involved. . 

. . I think that depending on the situation [a federal employee working with a patient sick with 

COVID-19] may be entitled to [HDP or EDP].

Id. at 1:00:25–1:01:10; see also id. at 1:01:10–1:03:31.

In light of these concessions, the court asked several 

related questions, including the following:

Q. [I]s there a situation which human-to-human 

contact could lead to exposure to a biologic that 

would entitle [Appellants] to hazardous duty pay?

A. There may be a narrow set of circumstances. . . . 

Id. at 47:47–48:25.

Q. Is your position that human-to-human contact 

that’s required as part of the job can lead to exposure to biologics and to compensation?

A. . . . Is there any situation in which being near 

another individual could give rise [to enhanced 

pay]? Potentially. 

Id. at 57:12–58:00.

To sum up the government’s position, I asked the government whether “there are circumstances wherein a correctional officer can be entitled to hazardous pay,” and the 

Case: 21-1662 Document: 68 Page: 33 Filed: 02/14/2023
10 ADAMS v. US

government responded “yes.”6 Id. at 56:05–21. This statement by the government, in my view, belies the argument

that Appellants have not alleged plausible claims. 

The majority dismisses out of hand the government’s 

stated position at oral argument. The majority asserts that 

the government’s answers at oral argument were “vague” 

and “open ended.” Maj. Op. at 19 n.8. But the “yes” or “no” 

question whether “there are circumstances wherein a correctional officer can be entitled to hazardous pay” was neither vague nor open ended. En Banc Oral Arg. at 56:05–

21. Nor was the answer “yes” vague or open ended. Id. 

There is no lack of clarity in either. 

Second, the majority determines that the government’s 

statements are “a weak basis for declining to give the Virulent Biologicals and Micro-organisms categories their best 

interpretation.” Maj. Op. at 19 n.8. But statements made 

by counsel before the en banc court are not a “weak basis”

for resolving the issue at hand. This court often accepts 

such statements as “concessions” or “admissions” and relies 

on them in reaching and writing its determinations. See 

Taylor Energy Co. LLC v. United States, 975 F.3d 1303, 

6 The government did not explain at the en banc oral 

argument why it changed its position. But one member of 

the en banc court remarked, “I know you are trying to not 

foreclose a reading that would give benefits to people in the 

future if they come up with a better argument,” and the 

government did not dispute it. En Banc Oral Arg. 1:02:58–

1:03:45. This effort to buoy the government’s position cements Appellants’ point that they have stated plausible 

claims for relief. It recognizes that the majority’s focus has 

been on whether Appellants proved entitlement and not

whether they stated plausible claims for relief. In addition, 

by not holding the government’s feet to its concessions, the 

majority unwisely takes this policy decision out of the government’s hands. 

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ADAMS v. US 11

1312 n.8 (Fed. Cir. 2020) (declining to consider a “compelling,” potentially “dispositive” argument because the government conceded it during oral argument); see also Checo 

v. Shinseki, 748 F.3d 1373, 1378 n.5 (Fed. Cir. 2014) (questioning a tribunal’s “reluctance to accept [the government’s] concession” in view of the general rule that 

admissions are binding (collecting cases)). The majority 

advances no persuasive reason why in this appeal we 

should treat the government’s responses to the court’s 

questions as weak.

Third, the majority argues that the government’s statements before the en banc court should be ignored because 

“the government has not argued in this case for any form 

of deference for its reading of OPM’s regulations.” Maj. Op. 

at 19 n.8. This argument misapprehends what is required 

at a Rule 12(b)(6) stage. Appellants need not prove that 

the government believes in and stands by its own statements made before the court.

The en banc statements undermine the majority’s holding which limits this element to employees that are “working directly or indirectly with” a virulent biological or 

microorganism. See Maj. Op. at 18–19 (stating that the 

regulations do not “encompass contagious-disease transmission via ambient exposure not resulting from working 

directly or indirectly with the virulent biological or pathogenic micro-organism”); id. at 4 (explaining that the regulations limit enhanced pay to “certain situations within 

laboratories”). Appellants’ complaint alleging COVID-19 

exposure, analogous to that of a healthcare worker, adequately pleads this element. See J.A. 27–33. 

In addition, there exists principled substantive reasons 

why COVID-19 exposure falls within the scope of the regulations and why the regulations are not limited to the narrower construction of “working directly or indirectly with 

the virulent biological or pathogenic micro-organism.” Maj. 

Op. at 18–19.

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12 ADAMS v. US

First, the government’s narrower “work directly or indirectly” interpretation is at odds with the common meaning of the regulatory language “work with or in close 

proximity to.” See, e.g., Proximity, Black’s Law Dictionary

(11th ed. 2019) (“The quality, state, or condition of being

near in time, place, order, or relation.” (emphasis added)). 

If the OPM intended to limit the phrase to mean only laboratory experimentation, it could have done so. But it 

chose instead to use a phrase that unambiguously encompasses COVID-19 exposure. See Conn. Nat. Bank v. Germain, 503 U.S. 249, 253–54 (1992) (“A court should always 

turn first to one, cardinal canon before all others . . . [w]hen 

the words of a statute are unambiguous, then, this first 

canon is also the last[.]”); see also Wis. Cent. Ltd. v. U.S., 

138 S. Ct. 2067, 2074 (2018) (“[W]ords generally should be 

interpreted as taking their ordinary, contemporary, [and] 

common meaning. . . .” (citation omitted)).

Limiting the regulations to the narrower construction 

of “working directly or indirectly” with COVID-19 also renders the phrase “in close proximity to” in the regulations 

superfluous. Corley v. United States, 556 U.S. 303, 314

(2009) (“[A] statute should be construed [to give effect] to 

all its provisions, so that no part will be inoperative or superfluous, void or insignificant.” (citation omitted)). Working “directly” or “indirectly” with something is still 

“working with” it. “In close proximity to” provides the regulations with expanded, not limited, scope. 

The government contends that because the section involving “Tropical Jungle Duty” of the HDP Schedule includes known exposure to disease, the other sections of the 

schedule necessarily exclude such exposure. Panel Resp. 

Br. at 33–35; see also Maj. Op. at 18–21 (discussing the 

Tropical Jungle Duty and Asbestos categories). This expressio unius argument is unpersuasive because the 

phrase “work with or in close proximity to” includes within 

its plain meaning “exposure to serious disease.” See 5 

C.F.R., Pt. 550, Subpt. I, App. A (HDP Schedule) (“work 

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ADAMS v. US 13

with or in close proximity to . . . Virulent biologicals . . . 

which when introduced into the body are likely to cause serious disease or fatality” (emphasis added)). As a result, I 

would not read out exposure from the broader phrase just 

because other sections of the HDP schedule cover narrower 

circumstances. Orlando Food Corp. v. U.S., 423 F.3d 1318, 

1325 (Fed. Cir. 2005) (“[T]he maxim expressio unius est exclusio alterius is not useful when its application would produce a result that is inconsistent with the plain language 

of the statute.”). It seems just as logical that the Tropical 

Jungle Duty category, which falls within the same schedule 

as the at-issue “virulent biologicals” category, supports an 

expansive reading because it shows that the OPM was 

aware of the risks associated with exposure to hazards and 

intended the regulations to encompass them.7 See Marx v. 

Gen. Revenue Corp., 568 U.S. 371, 381 (2013) (The canon 

“can be overcome by contrary indications that adopting a 

particular rule or statute was probably not meant to signal 

any exclusion.” (citation omitted)). 

Second, the narrower interpretation effectively eliminates the virulent biologicals and microorganisms categories because, as discussed above, the duty must also be 

unusual compared to the employee’s typical job duties. 

During oral argument before the panel, when pressed to 

explain what circumstances would permit HDP under the 

government’s proposed interpretation, the only example 

the government could provide was if someone untrained to 

7 The government also relied on examples of what 

qualifies for EDP in the regulation to argue that the “microorganism” category should be limited to those examples. 

Panel Resp. Br. at 29–31; see also Maj. Op. at 14–16 (applying a limiting interpretation because of the EDP examples). There is no compelling reason to narrow a 

regulation’s expansive scope because of non-limiting examples. 

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14 ADAMS v. US

work with viruses was required to harvest virulent tissue

culture. Oral Arg. at 31:00–31:30. But the regulations do 

not require a “training” or other similar limitations. This 

explanation exposes the weakness of the narrower reading,

and may have been a reason why the government conceded 

this position before the en banc court.8 See Lau Ow Bew v. 

United States, 144 U.S. 47, 59 (1892) (“Nothing is better 

settled than that statutes should receive a sensible construction, such as will effectuate the legislative intention, 

and, if possible, so as to avoid an unjust or an absurd conclusion.”); Green v. Brennan, 578 U.S. 547, 553–54 (2016) 

(applying canons of statutory interpretation to regulations).

Third, Adair does not compel the narrower interpretation. Contra Maj. Op. at 14–16. Adair considered a completely different factual situation—whether employees 

working around “inmates who incidentally smoke” constituted “[w]orking with or in close proximity to poisons (toxic 

chemicals).” Adair, 497 F.3d at 1257–58 (emphasis added). 

Appellants’ allegations here are substantially more aligned 

with the regulatory language and more plausible. See id. 

at 1258 (explaining that secondhand smoke was a “known 

8 The narrower interpretation also raises serious 

questions as to the regulations’ validity. Corley, 556 U.S. 

at 314; Belkin Int’l, Inc. v. Kappos, 696 F.3d 1379, 1384 

(Fed. Cir. 2012) (“[R]egulations cannot be interpreted to 

trump [] statutory command. . . .”). Nothing in the statutes

suggests that enhanced pay may be limited to employees 

who work “directly or indirectly” with a virus or microorganism in a laboratory. See 5 U.S.C. §§ 5545(d), 5343(c)(4)

(requiring merely that the hazard be unusual); see also En 

Banc Oral Arg. at 47:47–48:25, 57:12–1:03:31 (the government conceding that human-to-human contact could satisfy the “work with or in close proximity to” element). See 

supra note 2. 

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ADAMS v. US 15

hazard” that had long been “ubiquitous in the ambient 

work environment”).

Fourth, extrinsic materials support including 

COVID-19 exposure in the regulatory requirement. Contra 

Maj. Op. at 17–18, 22–23. On March 7, 2020, OPM published a memorandum (the “OPM Memo”), which explains 

that federal employees may recover EDP or HDP for 

COVID-19 exposure.9 U.S. Office of Personnel Management Questions and Answers on Human Resources Flexibilities and Authorities for Coronavirus Disease 2019 

(COVID-19), OPM Memorandum No. 2020-05, Attach. A at 

11–13 (Mar. 7, 2020).10 The OPM Memo provides that 

COVID-19 exposure falls within the HDP “virulent biologicals” category when the employee is “exposed to the virus 

during the performance of assigned duties (e.g., as in the 

9 For its part, the government relied on a non-operative Federal Personnel Manual, which provided examples 

of what qualified for HDP. En Banc Resp. Br. at 8–9 (citing 

Fed. Personnel Manual, Supp. 990-2 § 550-E-4); see also 

Maj. Op. at 17–18. Setting aside the expansive regulatory 

language, I do not believe non-limiting examples from a 

manual that was retired in 1993 are more persuasive than 

the 2020 OPM Memo that addresses the precise issue in 

this case.

10 During en banc argument I incorrectly stated that 

the OPM Memo was attached to Appellants’ complaint. In 

fact, the Appellants reference the OPM Memo in the complaint. See J.A. 27 (¶ 18); Celgene Corp. v. Mylan Pharms. 

Inc., 17 F.4th 1111, 1128 (Fed. Cir. 2021) (“[A] document 

integral to or explicitly relied upon in the complaint may 

be considered without converting the motion to dismiss 

into one for summary judgment.” (citation omitted)); Maj. 

Op. at 22 (noting that “both Appellants and the government argue that [the OPM Memo] is instructive and favorable to their respective positions”).

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16 ADAMS v. US

case of a poultry handler or health care worker)” but not 

when the employee is incidentally exposed “to the public or 

other employees who are ill.” Id. at 11–12. “Poultry handlers” and “health care workers” are obviously not laboratory employees working directly or indirectly with COVID19. These employees’ jobs, like the poultry handlers, require them to work closely with or around other people, 

subjecting the employees to the hazard of COVID-19 exposure while on the job. The OPM Memo also counsels that 

EDP may be granted in similar situations. Id. at 11–13.

Consistent with the OPM Memo, the government recognizes that agencies have awarded HDP and EDP for 

COVID-19 exposure or published internal guidance explaining that their employees may be entitled to enhanced 

pay for COVID-19 exposure. For instance, the government 

acknowledged that the Indian Health Service, an agency 

within Department of Health & Human Services, awarded 

enhanced pay for COVID-19 exposure. See En Banc Oral 

Arg. at 43:23–44:04; see also Brief for AFL-CIO as Amicus 

Curiae Supporting Appellants, 2022 WL 4354602 at *20–

21. The U.S. Department of the Interior likewise published 

guidance explaining that its employees may be entitled 

HDP or EDP. Memorandum from Raymond A. Limon, 

Deputy Assistant Secretary-Human Capital and Diversity 

Chief Human Capital Officer, to Human Capital Officers

(April 21, 2020); U.S. Dep’t of the Interior Human Resources Flexibilities Guide for Employees, Emergency Response Reference for Coronavirus Disease 2019 (COVID-19) 

at 10 (Mar. 3, 2020). On this point, we should recognize 

both what the government does and what it says.

In the majority’s view, “the OPM Memo does not speak 

with one clear, consistent voice” or provide “any interpretive analysis.” Maj. Op. at 22–23. But it cites no legal authority for such a rigid test. As discussed above, the OPM 

Memo—based on its text and how other agencies have understood it—is a persuasive extrinsic material for the interpretation issues in this case. 

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ADAMS v. US 17

The majority also states that it does not need to afford 

the OPM Memo “deference” because the OPM Memo did 

not go through “formal rulemaking.” Id. at 23. But the 

parties do not argue deference. See, e.g., En Banc Op. Br.

at 31–32; En Banc Resp. Br. at 40–41, 49. The OPM Memo 

illustrates, in the government’s own words, what the government practice was during the time period in question. 

It shows that HDP and EDP were available on a case-bycase basis for COVID-19 related risks. It evidences OPM’s 

understanding of its regulations’ scope and is therefore indicative of whether the regulations cover COVID-19 exposure.11 

Thus, the regulatory language encompasses COVID-19 

exposure, and Appellants plausibly alleged that they were 

assigned duties that required them to “work with or in 

close proximity to” a virulent biological or microorganism.

11 The majority states that “Appellants’ theory would 

broaden the Virulent Biologicals and Micro-organisms categories to cover . . . far more [employees] than any other 

category in the HDP and EDP Schedules. Administering 

such a differential pay would no doubt require significant 

amounts of investigation and review throughout the government on a workplace-to-workplace basis.” Maj. Op. at 

24. This court should not justify decisions based on policy 

considerations that more appropriately belong in the hallways and hearing rooms of Congress, or within agency policy-setting directorates. In any event, the majority’s policy 

considerations are belied by the record before this court 

given that agencies have published instructive guidance 

that addresses and unites HPD, EDP, and COVID-19 exposure. 

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18 ADAMS v. US

CONCLUSION

Appellants have stated plausible claims on which relief 

may be granted. Questions of fact remain to determine ultimately whether, and which, Appellants are entitled to 

any, and what amount of HDP, EDP, and the derivative 

claims. For these reasons, I respectfully dissent.

Case: 21-1662 Document: 68 Page: 42 Filed: 02/14/2023