  United States Court of Appeals
      for the Federal Circuit
                ______________________

           MICHAEL J. O’FARRELL, JR.,
                   Petitioner

                          v.

           DEPARTMENT OF DEFENSE,
                    Respondent
              ______________________

                      2017-1223
                ______________________

   Petition for review of the Merit Systems Protection
Board in No. DE-4324-14-0013-I-1.
                ______________________

              Decided: February 9, 2018
               ______________________

    DANIEL CRAIG COOLEY, Finnegan, Henderson,
Farabow, Garrett & Dunner, LLP, Reston, VA, argued for
petitioner.  Also    represented   by    J.    DEREK
MCCORQUINDALE; SYDNEY KESTLE, JASON LEE ROMRELL,
Washington, DC.

    JOSEPH ASHMAN, Commercial Litigation Branch, Civil
Division, United States Department of Justice, Washing-
ton, DC, argued for respondent. Also represented by
CHAD A. READLER, ROBERT E. KIRSCHMAN, JR., DOUGLAS K.
MICKLE.
                 ______________________
2                                  O’FARRELL   v. DEP’T OF DEF.



    Before DYK, MOORE, and WALLACH, Circuit Judges.
WALLACH, Circuit Judge.
     Petitioner Michael J. O’Farrell, Jr. appealed to the
Merit Systems Protection Board (“MSPB”), alleging, inter
alia, that his employing agency, the U.S. Department of
Defense (“DOD” or “Government”) failed to grant him
military leave for active military service in violation of the
Uniformed Services Employment and Reemployment
Rights Act of 1994 (“USERRA”), Pub. L. No. 103-353, 108
Stat. 3149 (codified as amended at 38 U.S.C. §§ 4301–
4333 (2012)). 1 An administrative judge (“AJ”) issued an
initial decision denying Mr. O’Farrell’s claim and dismiss-
ing his appeal. See O’Farrell v. Dep’t of Def. (O’Farrell I),
No. DE-4324-14-0013-I-1, 2016 WL 1014371 (M.S.P.B.
Mar. 8, 2016) (J.A. 4–14). On review, the full MSPB
issued an order stating that “[t]he two [MSPB] members
cannot agree on the disposition of the petition for review,”
such that O’Farrell I “now becomes the final decision of
the [MSPB] in this appeal.” O’Farrell v. Dep’t of Def.
(O’Farrell II), 123 M.S.P.R. 590, 591 (2016) (footnote
omitted). 2



    1   Relevant here, the USERRA provides that
    [a] person who is a member of, applies to be a
    member of, performs, has performed, applies to
    perform, or has an obligation to perform service in
    a uniformed service shall not be denied . . . any
    benefit of employment by an employer on the ba-
    sis of that membership, application for member-
    ship, performance of service, application for
    service, or obligation.
38 U.S.C. § 4311(a).
    2   Accordingly, we refer to the AJ’s and MSPB’s rea-
soning interchangeably.
O’FARRELL   v. DEP’T OF DEF.                                    3



    Mr. O’Farrell appeals. We have jurisdiction pursuant
to 28 U.S.C. § 1295(a)(9) (2012). We reverse.
                         BACKGROUND
                   I. Statutory Framework
     When certain reserve military personnel who are em-
ployed by the Government are called to active duty, they
are “entitled to leave without loss in pay, time, or perfor-
mance or efficiency rating” that “accrues . . . at the rate of
[fifteen] days per fiscal year.” 5 U.S.C. § 6323(a)(1)
(2012). In addition to these fifteen days,
    an employee . . . who—(1) is a member of a Re-
    serve component of the Armed Forces . . . ; and
    (2) . . . (B) performs full-time military service as a
    result of a call or order to active duty in support of
    a contingency operation as defined in [10 U.S.C.
    §] 101(a)(13) [(2012)] . . . ; is entitled . . . to leave
    without loss of, or reduction in, pay, leave to
    which he otherwise is entitled, credit for time or
    service, or performance or efficiency rating . . .
    [that] shall not exceed [twenty-two] workdays in a
    calendar year.
Id. § 6323(b) (emphasis added).        In turn, “contingency
operation” is defined to include:
    a military operation that . . . (B) results in the call
    or order to, or retention on, active duty of mem-
    bers of the uniformed services under [10 U.S.C.
    §§] 688, 12301(a), 12302, 12304, 12304a, 12305, or
    12406 . . . , [10 U.S.C.] ch[.] 15 . . . , [14 U.S.C.
    §] 712 . . . , or any other provision of law . . . dur-
    ing a national emergency declared by the President
    or Congress.
10 U.S.C. § 101(a)(13) (emphasis added). Military reserve
personnel “call[ed] or order[ed] to active duty under a
provision of law referred to in [§] 101(a)(13)(B) . . . shall
4                                  O’FARRELL   v. DEP’T OF DEF.



be entitled . . . to receive” payment commensurate with
the difference between the civilian pay they would have
received and their military pay for their period of active
duty service. 5 U.S.C. § 5538(a).
        II. Factual Background and Procedural History
     Mr. O’Farrell served in the U.S. Army for twenty-
eight years. 3 J.A. 174. During Mr. O’Farrell’s service, on
September 11, 2012, President Barack Obama published
a notice in the Federal Register “continuing for [one] year
the national emergency . . . with respect to the terrorist
attacks of September 11, 2001, and the continuing and
immediate threat of further attacks on the United
States.” Continuation of the National Emergency with
Respect to Certain Terrorist Attacks, 77 Fed. Reg. 56,517,
56,517 (Sept. 11, 2012). At the time, Mr. O’Farrell
worked as a General Attorney in the Office of Counsel for
the aviation subordinate command of the Defense Logis-
tics Agency (“DLA”) within DOD. J.A. 174. However, on
April 17, 2013, Mr. O’Farrell received an order from the
U.S. Army directing him to replace a civilian attorney
employed with the U.S. Navy’s Naval Surface Warfare
Center (“NSWC”), Corona Division, in California.
J.A. 114; see J.A. 175. The NSWC attorney, who also was
a member of the U.S. Army Reserve, was replaced be-
cause he had been deployed to Afghanistan. J.A. 175.
The Order directing Mr. O’Farrell provided:
    You are ordered to active duty for operational sup-
    port under provision of [10 U.S.C. §] 12301 (d) . . .



    3   “[A]fter reaching [the] maximum total years of ac-
tive commissioned service for his rank (28 years),” Mr.
O’Farrell “was transferred to the U.S. Army Reserve
Retired List” in October 2013. J.A. 174. It is undisputed
that Mr. O’Farrell was a member of the U.S. Army Re-
serve at all times relevant to this appeal. J.A. 5.
O’FARRELL   v. DEP’T OF DEF.                              5



   for the period shown plus the time necessary to
   travel. You will proceed from your home or cur-
   rent location in time to report for duty on [April
   22, 2013]. Upon completion of this duty, unless
   sooner released, you will return to your home and
   upon arrival be released from active duty.
J.A. 114 (capitalization modified) (emphasis added). The
Order further stated that Mr. O’Farrell’s “operational
support” would consist of his “serv[ic]e as[] legal counsel”
at NSWC. J.A. 114 (capitalization omitted).
     After receiving the Order, Mr. O’Farrell served his ac-
tive duty as legal counsel at NSWC for a total of 162 days
until September 30, 2013. J.A. 174. The parties do not
dispute that, by August 26, 2013, Mr. O’Farrell had used
his fifteen days of military leave pursuant to § 6323(a)(1),
as well as most of his accrued annual leave and advance
annual leave. See J.A. 5–6. To avoid being placed on
Military Leave Without Pay for the remainder of his
active duty service, Mr. O’Farrell requested an additional
twenty-two days leave pursuant to § 6323(b) in an email
exchange with a representative at DLA. See J.A. 102–13.
Although Mr. O’Farrell acknowledged that the Order did
not cite any of the statutory provisions listed in
§ 101(a)(13) that qualify as support for a contingency
operation, he explained that he was “serving under ‘any
other provision of law . . . during a national emergency
declared by the President or Congress,’ . . . because . . .
[§] 12301(d) is ‘any other provision of law’ and[,] on Sep-
tember 11, 2012[,] President Obama extended the state of
emergency that has existed since September 11, 2001.”
J.A. 104 (quoting 10 U.S.C. § 101(a)(13)). DLA informed
Mr. O’Farrell by email that he was not entitled to addi-
tional military leave pursuant to § 6323(b) because the
Order “do[es] not state [that Mr. O’Farrell was] under
contingency orders.”       J.A. 102.   Subsequently, Mr.
O’Farrell submitted an Office of Personnel Management
(“OPM”) Form 71, Request for Leave or Approved Ab-
6                                  O’FARRELL   v. DEP’T OF DEF.



sence, “[r]equest[ing] approval and use of [twenty-two]
days . . . of additional military leave under provisions
of . . . [§] 6323(b).” J.A. 100. DLA denied his request,
stating that Mr. O’Farrell’s “active duty is not in support
of a contingency operation.” J.A. 96; see J.A. 94–99.
                        DISCUSSION
     This appeal concerns whether, under the proper stat-
utory construction of § 6323(b), the MSPB erred in deny-
ing Mr. O’Farrell’s request for twenty-two days of
additional military leave. See Pet’r’s Br. 14; Resp’t’s Br. 1.
After articulating the applicable standard of review, we
first assess whether the MSPB properly construed
§ 6323(b) and then assess whether Mr. O’Farrell is enti-
tled to additional leave under the proper construction.
                   I. Standard of Review
    We affirm an MSPB decision unless, inter alia, it con-
stitutes “an abuse of discretion.” 5 U.S.C. § 7703(c)(1).
“The MSPB abuses its discretion when the decision is
based on an erroneous interpretation of the law, on factu-
al findings that are not supported by substantial evi-
dence, or represents an unreasonable judgment in
weighing relevant factors.” Tartaglia v. Dep’t of Veterans
Affairs, 858 F.3d 1405, 1407–08 (Fed. Cir. 2017) (internal
quotation marks and citation omitted). “We review the
[MSPB]’s legal determinations, including its interpreta-
tion of a statute, de novo.” Archuleta v. Hopper, 786 F.3d
1340, 1346 (Fed. Cir. 2015) (citation omitted).
     II. The MSPB Misinterpreted 5 U.S.C. § 6323(b)
    Without engaging in the appropriate statutory analy-
sis, the MSPB summarily determined that § 6323(b)
requires that “a specific contingency operation should be
identified in military orders when an employee is activat-
ed under [§] 12301(d) in order for the employee to be
entitled to [twenty-two] days of additional military leave
under [§] 6323(b).” J.A. 8. The MSPB, however, failed to
O’FARRELL   v. DEP’T OF DEF.                                7



assess what qualifies as “support” or as a “contingency
operation” under the relevant statutory provisions.
Therefore, we interpret § 6323(b) and § 101(a)(13) to
determine the meaning of these respective terms, as well
as whether these statutes require that the order calling
the service member to active duty must identify the
specific contingency operation.
    We begin our statutory interpretation with the plain
language of § 6323(b). See BedRoc Ltd. v. United States,
541 U.S. 176, 183 (2004). As an initial matter, the statute
requires that the service member “perform[] full-time
military service as a result of a call or order to active duty
in support of a contingency operation.”             5 U.S.C.
§ 6323(b)(2)(B) (emphasis added); it does not, however,
specify the types of “support” that qualify. Therefore, we
interpret “support” in accordance with its “ordinary,
contemporary, common meaning,” Sandifer v. U.S. Steel
Corp., 134 S. Ct. 870, 876 (2014) (internal quotation
marks and citation omitted), which broadly encompasses
“an act of helping a person or thing to hold firm or not to
give way; provision of assistance or backing,” Support,
The Oxford English Dictionary (3d ed. 2012) (emphasis
added), available at http://www.oed.com/view/Entry/
194673; see Support, The New Oxford American Diction-
ary (2005) (“To give assistance to, esp. financially; enable
to function or act.” (emphasis added)); Support, The
American Heritage Dictionary (2000) (“To aid the cause,
policy or interests of.”). Contrary to the Government’s
assertions, see Resp’t’s Br. 22–23, § 6323(b) imposes no
requirement that the service member provide direct, as
opposed to indirect, support to the contingency operation.
    Section 101(a)(13), in turn, defines what constitutes a
“contingency operation” for purposes of § 6323(b). A
8                                  O’FARRELL   v. DEP’T OF DEF.



contingency operation must be a “military operation,” 4 10
U.S.C. § 101(a)(13), and the military operations that
qualify as contingency operations include, as relevant
here, those that “result[] in the call or order to, or reten-
tion on, active duty of members of the uniformed services
under [certain listed statutory provisions], or any other
provision of law . . . during a national emergency declared
by the President,” id. § 101(a)(13)(B) (emphases added).
Section 101(a)(13)(B) thus requires that service members
be called to, or retained on, active duty pursuant to a
“provision of law . . . during a national emergency.” While
§ 101(a)(13)(B) lists specific statutory provisions under
which a service member may be ordered to active duty,
the subsection’s use of the word “any” indicates that this
list of statutory provisions is non-exhaustive and that
“other provision[s] of law” should be interpreted broadly.
See Ali v. Fed. Bureau of Prisons, 552 U.S. 214, 219 (2008)
(“Read naturally, the word ‘any’ has an expansive mean-
ing, that is, ‘one or some indiscriminately of whatever


    4    Neither § 101(a)(13) nor the remainder of Title 5
of the U.S. Code define “military operation.” In addition,
the parties neither request that we interpret that term
nor contend that the armed forces of the United States’
actions in Afghanistan in conjunction with the national
emergency arising from the terrorist attacks of September
11, 2001, are not related to a contingency operation. See
10 U.S.C. § 101(a)(13); Continuation of the National
Emergency with Respect to Certain Terrorist Attacks, 77
Fed. Reg. at 56,517; cf. Oral Arg. at 15:41–45,
http://oralarguments.cafc.uscourts.gov/default.aspx?fl=
2017-1223.mp3 (acknowledging that the armed forces
“have been in open hostilities since at least 2001”). See
generally Pet’r’s Br.; Resp’t’s Br. At the very least, how-
ever, a military operation by the armed forces of the
United States includes engagement in open hostilities
against the nation’s enemies.
O’FARRELL   v. DEP’T OF DEF.                               9



kind.’” (citation omitted)).      Therefore, § 101(a)(13)(B)
instructs that a service member may be called to active
duty “in support of a contingency operation” pursuant to
§ 6323(b), even if the service member were ordered to
active duty pursuant to a provision of law that is not
explicitly listed in § 101(a)(13)(B).
     We next consider § 6323(b) in the context of the over-
all statutory scheme. See Davis v. Mich. Dep’t of Treas-
ury, 489 U.S. 803, 809 (1989). While 5 U.S.C. §§ 6321–
6329c, the subchapter of Title 5 of the U.S. Code involving
“Other Paid Leave,” generally describes circumstances
under which a service member may qualify for paid leave,
none of these provisions inform our interpretation of “in
support of” or “contingency operation.” However, 5 U.S.C.
§§ 5101–5949, the subpart of Title 5 of the U.S. Code
involving “Pay and Allowances,” specifies that a service
member must have provided direct support for a contin-
gency operation to qualify for certain benefits. See, e.g., 5
U.S.C. § 5742(b)(2)(B)(ii)(I)(bb) (providing that an agency
may pay transportation costs of a deceased employee
when the employee, inter alia, died as a result of harm
suffered in the performance of official duties “in direct
support of or directly related to a military operation,
including a contingency operation (as defined in
[§] 101(a)(13) . . . ) or an operation in response to an
emergency declared by the President” (emphasis added)).
Congress knew how to require direct support of contin-
gency operations but declined to include such a qualifier
in § 6323(b). See Sebelius v. Cloer, 569 U.S. 369, 378
(2013) (“We have long held that where Congress includes
particular language in one section of a statute but omits it
in another section of the same Act, it is generally pre-
sumed that Congress acts intentionally and purposely in
the disparate inclusion or exclusion.” (internal quotation
marks, brackets, and citation omitted)).
    We also may look to the relevant regulatory scheme to
inform our interpretation of § 6323(b). See Bragdon v.
10                                  O’FARRELL   v. DEP’T OF DEF.



Abbott, 524 U.S. 624, 642 (1998). While related statutory
provisions contemplate the promulgation of regulations,
see 5 U.S.C. § 6322(c) (“[OPM] may prescribe regulations
for the administration of this section.”); id. § 6324(b)
(providing that “[t]he determination of whether an injury
or illness resulted from the performance of duty shall be
made under regulations prescribed by” relevant councils
and secretaries), no relevant agency “has (under any other
statutory authority) promulgated a formal rule setting
forth its implementation of [§] 6323,” Butterbaugh v. Dep’t
of Justice, 336 F.3d 1332, 1340 (Fed. Cir. 2003). The
regulatory scheme thus does not aid our interpretation of
the terms “in support of” or “contingency operation.”
However, it does illuminate whether a service member
ordered to active duty must identify a specific contingency
operation when requesting additional leave. Indeed, the
sole relevant regulation identified by the court states that
a service member “must be permitted, upon request, to
use any . . . military leave under 5 U.S.C. [§] 6323 . . . , if
appropriate, during . . . service.”    5 C.F.R. § 353.208
(2016). The use of the mandatory term “must” indicates
that OPM is required to provide service members with
additional leave “upon request,” id.; see Kingdomware
Techs., Inc. v. United States, 136 S. Ct. 1969, 1977 (2016)
(stating that “the word ‘shall’ usually connotes a require-
ment” and equating “shall” with “must”), as long as leave
is “appropriate” under the requirements set forth in
§ 6323, 5 C.F.R. § 353.208. Moreover, contrary to the
Government’s assertions, see Resp’t’s Br. 13 (arguing that,
to be entitled to additional leave pursuant to § 6323(b), a
service member must “identify the military operation that
their service supported” and “show how his or her service
supported a military operation”), no regulation places
requirements on the form of the service member’s request,
see, e.g., 5 C.F.R. § 353.208.
    We also may look to the legislative history to inform
our interpretation of § 6323(b). See Thunder Basin Coal
O’FARRELL   v. DEP’T OF DEF.                               11



Co. v. Reich, 510 U.S. 200, 207 (1994). By the 1960s,
Congress grew concerned that service members increas-
ingly were being called to active duty in response to “civil
disturbances,” requiring them to “take annual leave or go
on leave without pay,” and that this caused substantial
hardship for “enlisted men, who in private life may earn
substantially more than their pay as Guardsmen or
reservists.” S. Rep. No. 90-1443, at 4289 (1968). Con-
gress thus amended § 6323 to provide additional leave to
service members. See Pub. L. No. 90-588, § 2(a), 82 Stat.
1151, 1151–52 (1968). When Congress again amended
§ 6323 to provide additional leave for service members
ordered to active duty in support of contingency opera-
tions, see National Defense Authorization Act for Fiscal
Year 2004, Pub. L. No. 108-136, § 1113, 117 Stat. 1392,
1635 (2003) (adding the “in support of a contingency
operation” language), it expressed concern that a service
member serving “in a contingency operation in support of
our troops in Afghanistan or Iraq combat zones happens to
be left out” of certain benefits, 149 Cong. Rec. S12,582
(daily ed. Oct. 15, 2003) (statement of Sen. Lincoln) (em-
phasis added) (discussing tax benefits enacted contempo-
raneously with the amendments to § 6323). In addition,
when Congress added a definition of “contingency opera-
tion” in § 101(a)(13) in 1991, it did so in response to, inter
alia, its assessment that “[DOD] . . . was not sufficiently
sensitive to the sacrifices made by reservists called or
ordered to active duty in connection with the Persian Gulf
conflict and by the families, employers, and communities
of those reservists.” National Defense Authorization Act
for Fiscal Years 1992 and 1993, Pub L. No. 102-190,
§ 555(a)(1), 105 Stat. 1290, 1372 (1991) (emphasis added).
This legislative history indicates that Congress continual-
ly updated § 6323 and § 101(a)(13) to provide for increas-
ing numbers of service members to receive additional
compensation in response to the changing nature of
military conflicts.
12                                O’FARRELL   v. DEP’T OF DEF.



      As relevant here, these statutory provisions, regula-
tions, and legislative history collectively instruct that
under the current landscape: (1) “in support of” includes
indirect assistance to a contingency operation, 5 U.S.C.
§ 6323(b)(2)(B); see Support, The Oxford English Diction-
ary (3d ed. 2012); Support, The New Oxford American
Dictionary (2005); Support, The American Heritage
Dictionary (2000); (2) “contingency operation” includes a
military operation that results in service members being
called to active duty under any provision of law during a
national emergency, 10 U.S.C. § 101(a)(13); (3) upon
request, a service member is entitled to additional leave
as long as leave is “appropriate” under the requirements
set forth in § 6323, 5 C.F.R. § 353.208; and (4) the service
member’s request for additional leave need not take any
particular form or use any particular language, see, e.g.,
id. 5
III. The MSPB Abused Its Discretion in Determining that
 Mr. O’Farrell Is Not Entitled to Additional Leave Under
                        § 6323(b)
    Applying its erroneous interpretation of § 6323(b), the
MSPB determined that Mr. O’Farrell “failed to meet his
burden of proving his rights under USERRA were violated
when [DLA] denied him [twenty-two] days of additional
leave under . . . § 6323(b).” J.A. 8. As discussed above,
see supra Section II, the MSPB based its conclusion on its
erroneous construction of § 6323(b), see J.A. 8, which
constitutes an abuse of discretion, see Tartaglia, 858 F.3d
at 1407–08. Under the proper construction of § 6323(b),



     5   Our holding today does not mean that all reserv-
ists called to active duty during a national emergency will
be entitled to additional leave. Instead, they must
demonstrate that their call to active duty was “in support
of a contingency operation,” as properly construed.
O’FARRELL   v. DEP’T OF DEF.                             13



we conclude that Mr. O’Farrell is entitled to additional
leave.
    It is undisputed that the armed forces of the United
States are engaged in military operations in Afghanistan
in conjunction with a national emergency declared by the
President that constitutes a contingency operation. See
supra n.4. Instead, the parties dispute whether Mr.
O’Farrell was called to active duty “in support of” that
contingency operation. See Pet’r’s Br. 26–27; Resp’t’s Br.
21–23. The record is clear that he was because Mr.
O’Farrell replaced an NSWC attorney who directly sup-
ported the contingency operation through his deployment
to Afghanistan. See J.A. 114, 175; see also Resp’t’s Br. 3
(“Mr. O’Farrell’s service was required in order to replace a
Navy civilian attorney who had been activated from
reserve status and deployed to Afghanistan.”). We also
note that, in replacing that attorney, Mr. O’Farrell pro-
vided assistance to the Navy’s warfighting capabilities
while serving on active duty at NSWC. See J.A. 184–86
(describing NSWC’s objectives and mission as, inter alia,
“provid[ing] the fleet, program managers[,] and acquisi-
tion community with the objective assessment needed for
the Navy to gauge the warfighting capability of ships and
aircraft, assess warfare training[,] and analyze new
defense systems” and as “[s]erv[ing] warfighters and
program managers as the Navy’s independent perfor-
mance assessment agent throughout systems’ lifecycles by
gauging the Navy’s warfighting capability of weapons and
integrated combat systems, from unit to force level”), 190
(commending Mr. O’Farrell for “facilitat[ing the] smooth
workflow and assured success in the legal aspects of
NSWC[’s] . . . mission”). Indeed, the Order calling Mr.
O’Farrell to active duty pursuant to § 12301(d), which
undoubtedly qualifies as a “provision of law,” states that
he will provide “operational support” for this mission.
J.A. 114 (emphasis added).
14                                O’FARRELL   v. DEP’T OF DEF.



    The Government’s counterarguments are unpersua-
sive. First, the Government contends that, “[u]nlike other
similarly situated Federal civilian employees ordered to
active duty under [§] 12301(d), Mr. O’Farrell’s orders did
not indicate that the Navy considered his service to be in
support of a contingency operation.” Resp’t’s Br. 22.
Compare J.A. 114 (Mr. O’Farrell’s Order), with J.A. 115
(ordering another service member to active duty in sup-
port of a “contingency,” i.e., “Operation Enduring Free-
dom” (capitalization modified)).           However, the
Government acknowledges that our inquiry is not limited
to the text of an ambiguous order and that we may con-
sider other relevant evidence as to whether Mr. O’Farrell
was ordered to active duty “in support of a contingency
operation,” see Resp’t’s Br. 15 (“An employee’s orders are
an obvious starting point for the inquiry, but if it is not
clear on their face how her active duty service supported a
military operation related to a declared national emer-
gency, the employee may present evidence demonstrating
that the requirement was satisfied.” (citation omitted)),
and, as explained above, Mr. O’Farrell was called to active
duty “in support of” a “contingency operation” pursuant to
a “provision of law” and “during a national emergency,”
which is all the relevant statutory provisions require, see
supra Section II.
    Second, and relatedly, the Government asserts that
“Mr. O’Farrell did not argue before the [MSPB] that his
service was in support of a specific military operation
connected to a declared national emergency,” Resp’t’s
Br. 17 (emphasis added), such that “he cannot do so on
appeal,” id. at 20 (citation omitted). However, the rele-
vant inquiry is whether Mr. O’Farrell was called to active
duty “in support of a contingency operation,” not whether
he identified the specific contingency operation. See supra
Section II. Moreover, before both DLA and the MSPB,
Mr. O’Farrell argued that he was entitled to additional
leave pursuant to § 6323(b) on the grounds that he was
O’FARRELL   v. DEP’T OF DEF.                             15



called to active duty in support of a contingency operation
during a national emergency declared by the President.
See J.A. 104 (arguing before DLA that, “during a national
emergency declared by the President” as required by
§ 101(a)(13), he was ordered to active duty pursuant to
§ 12301(d), which is a “provision of law” (citation omit-
ted)), 322 (arguing before the MSPB that, “during the
period during which [Mr. O’Farrell] was serving on active
duty in support of the U.S. Navy, the U.S. Navy was
engaged in the performance of military operations
throughout the world, many of which were ‘contingency
operations’”).
    Third, the Government avers that Mr. O’Farrell pro-
vided only “loosely-connected ‘indirect support’” and “the
record does not show the necessary connection between
Mr. O’Farrell’s service and a military operation connected
with a declared national emergency.” Resp’t’s Br. 23.
However, we concluded above that indirect support for
contingency operations is sufficient under § 6323(b). See
supra Section II. Moreover, although not necessary to our
analysis, if there were any “interpretative doubt” as to
whether § 6323(b) imposed the additional requirements
sought by the Government, it would be “resolved in [Mr.
O’Farrell]’s favor.” Kirkendall v. Dep’t of the Army, 479
F.3d 830, 846 (Fed. Cir. 2007) (en banc) (internal quota-
tion marks and citation omitted); see King v. St. Vincent’s
Hosp., 502 U.S. 215, 220 n.9 (1991) (“[P]rovisions for
benefits to members of the Armed Services are to be
construed in the beneficiaries’ favor.” (citation omitted)).
Thus, it would be particularly improper to read these
additional requirements into the statute’s plain language.
                          CONCLUSION
   We have considered the Government’s remaining ar-
guments and find them unpersuasive. Accordingly, the
Final Decision of the Merit Systems Protection Board is
                         REVERSED
