  United States Court of Appeals
      for the Federal Circuit
                 ______________________

       JUDITH MISKILL, AFGE LOCAL 1923,
                  Petitioners

                            v.

      SOCIAL SECURITY ADMINISTRATION,
                    Respondent
              ______________________

                       2016-1598
                 ______________________

  Petition for review of an arbitrator’s decision in No.
BW-2014-R-0004 by Jonathan E. Kaufman.
                ______________________

                 Decided: July 20, 2017
                 ______________________

   THOMAS J. GAGLIARDO, AFGE Local 1923, Baltimore,
MD, argued for petitioners. Also represented by DEBRA
D’AGOSTINO, The Federal Practice Group Worldwide
Service, Washington, DC.

    MEEN GEU OH, Commercial Litigation Branch, Civil
Division, United States Department of Justice, Washing-
ton, DC, argued for respondent. Also represented by
BENJAMIN C. MIZER, ROBERT E. KIRSCHMAN, JR.,
ELIZABETH M. HOSFORD; KATHLEEN LOUISE HENLEY
PETTY, Office of the General Counsel, United States Social
Security Administration, Baltimore, MD.
                  ______________________
2                                            MISKILL   v. SSA



    Before O’MALLEY, HUGHES, and STOLL, Circuit Judges.
HUGHES, Circuit Judge.
    Judith Miskill challenges an Arbitrator’s award sus-
taining her removal by the Social Security Administration
for violations of the Agency’s time and attendance policy.
Because the Arbitrator’s decision is not in accordance
with law, we vacate and remand.
                             I
    Ms. Miskill was employed as an Information Technol-
ogy Specialist with the Social Security Administration
(the Agency) for more than 14 years. On August 16, 2013,
Larry Schwab, Ms. Miskill’s first-line supervisor, pro-
posed to remove Ms. Miskill for violations of the Agency’s
time and attendance policy between July 1, 2011 and
June 28, 2013. Mr. Schwab charged Ms. Miskill with: 1)
Extending Lunch Period and Break Periods; 2) Failure to
Accurately Record Arrival Times; 3) Failure to Accurately
Record Departure Times; and 4) Receiving Overtime Pay
or Compensatory Time Off When Ineligible. On Septem-
ber 25, 2013, Assistant Associate Commissioner Dan
Parry sustained all four charges against Ms. Miskill and
removed her from Federal Service.
    On November 6, 2013, the American Federation of
Government Employees (the Union) submitted a griev-
ance on behalf of Ms. Miskill asserting that the removal
“violated the just cause, progressive discipline and warn-
ing and counseling provisions contained in Article 23,
Section 1, the timeliness provisions of Article 23, Section
2 and the requirements of Douglas v. Veterans Admin., 5
MSPR 313 (1981) . . . .” J.A. 302. On December 3, 2013,
after Executive Officer Don Henry denied the grievance,
the Union invoked arbitration.
    In preparation for the arbitration hearing, Ms. Miskill
requested the turnstile records and time reports of the
eight other individuals within her component at the
MISKILL   v. SSA                                         3



Division of Network Engineering (DNE) between July 1,
2011 and June 28, 2013. The Agency provided the records
to her in August and November 2014. Those records were
analyzed by Candace Dayton, a Certified Public Account-
ant, Certified Product Examiner, and Certified Infor-
mation Technology professional. J.A. 132. Based on
those records, Ms. Dayton concluded that the eight other
DNE employees had committed the same or similar
violations as Ms. Miskill, yet not one of these eight em-
ployees was investigated or charged with misconduct.
Specifically, Ms. Dayton found that: (1) six DNE employ-
ees had more error minutes than Ms. Miskill for inaccu-
rately recording lunch and break periods; (2) four DNE
employees had more error minutes than Ms. Miskill for
inaccurately recording their arrival time; (3) four DNE
employees had more error minutes than Ms. Miskill for
inaccurately recording their exit time; and (4) one DNE
employee had more error minutes than Ms. Miskill for
inaccurately recording overtime. Ms. Dayton concluded
that five employees had more overall error minutes than
Ms. Miskill.
    Ms. Dayton’s analysis was provided to the Agency on
June 17, 2015. The Arbitrator held a hearing on the
merits on September 2, 2015. The Arbitrator received
into evidence Ms. Dayton’s analysis showing the time and
attendance discrepancies of the eight other DNE employ-
ees. Based on this evidence, Ms. Miskill argued that the
penalty of removal was too harsh when “eight other
comparators, employees working within DNE, also en-
gaged in similar misconduct . . . but had not been disci-
plined.” J.A. 4. At the end of the hearing, the parties
stipulated that the comparator employees were under
investigation for potential violations of the Agency’s time
and attendance policy, but had not yet been charged with
any misconduct. J.A. 196–97. On December 19, 2015,
the Arbitrator sustained Ms. Miskill’s removal after
finding that “the eight comparators were [not] similarly
4                                              MISKILL   v. SSA



situated to [Ms. Miskill] because, based on a stipulation of
the parties, the possible disciplinary action regarding
these other employees is still pending an investigation.”
J.A. 4.
   Ms. Miskill appeals. We have jurisdiction under 5
U.S.C. § 7121(f) and § 7703(a).
                             II
    Federal employees who are also union members may
challenge removal either by direct appeal to the Board or
through arbitration (with exceptions not applicable here).
5 U.S.C. § 7121(e)(1). We review an arbitrator’s decision
under the same standard of review that is applied to
decisions from the Merit Systems Protection Board. Id. §
7121(f); Johnson v. Dep’t. of Veterans Affairs, 625 F.3d
1373, 1376 (Fed. Cir. 2010). Thus we must affirm the
decision of the arbitrator unless it is: “(1) arbitrary,
capricious, an abuse of discretion, or otherwise not in
accordance with law; (2) obtained without procedures
required by law, rule, or regulation having been followed;
or (3) unsupported by substantial evidence.” 5 U.S.C. §
7703(c)(1)–(3). This standard of review “contemplates de
novo review of questions of law.” Johnson, 625 F.3d at
1376.
                             A
    The government argues that the Arbitrator violated
the Collective Bargaining Agreement (CBA) by consider-
ing Ms. Miskill’s evidence regarding the time and attend-
ance violations of the eight DNE employees.
    The CBA states:
    Only issues identified in the written grievance
    will be considered by the grievance deciding offi-
    cial. Neither party may consider issues that were
    not raised at the last step of the grievance process.
MISKILL   v. SSA                                         5



   An arbitrator may only consider issues that were
   raised at the last step of the grievance process.
J.A. 246 (emphasis added).
    Under the government’s interpretation, the CBA pro-
hibits the Arbitrator from considering evidence related to
a disparate treatment defense unless that specific de-
fense—the “issue” under the CBA—has been presented to
the Agency during the grievance process.
    “Interpretation of a collective-bargaining agreement is
a question of law we review de novo.” Garcia v. Dep’t of
Homeland Sec., 780 F.3d 1145, 1147 (Fed. Cir. 2015). The
Court “begin[s] with the plain language of the agreement”
and then “give[s] the words in the agreement their ordi-
nary meaning unless the parties mutually intended and
agreed to an alternative meaning.” Id. (citing Harris v.
Dep’t of Veterans Affairs, 142 F.3d 1463, 1467 (Fed. Cir.
1998)).
    Here, we conclude that the CBA does not require that
all evidence supporting an “issue” must be raised before
the Agency in order for the Arbitrator to properly consider
it. Thus, we decline to interpret “issue” as narrowly as
the government insists. Ms. Miskill’s grievance stated
that her removal was, inter alia, not in compliance with
the requirements of Douglas v. Veterans Administration,
5 M.S.P.R. 280 (1981). J.A. 302. One of the Douglas
factors requires agencies, when determining a penalty, to
consider the consistency of the penalty with those im-
posed upon other employees for the same or similar
offences. 5 M.S.P.R. at 305. Accordingly, by arguing that
the Agency failed to properly consider the Douglas factors,
Ms. Miskill sufficiently raised the issue of disparate
treatment. That she did not present evidence supporting
the disparate treatment argument until arbitration is of
no consequence as the CBA does not impose such a re-
quirement. Therefore, the Arbitrator did not err by
considering the comparator employee evidence.
6                                            MISKILL   v. SSA



                            B
    The arbitrator did err, however, in its treatment of
that comparator evidence. Specifically, the arbitrator’s
categorical conclusion that the eight DNE employees
could not be comparator employees because they were
under investigation is an incorrect statement of the law.
Although the fact that a comparator employee is under
investigation is a factor to be considered in determining
whether that comparator is similarly situated, it is not a
complete bar.
     “Arbitrators, like the Board, must review de novo the
merits of an agency’s decision to take adverse action
against an employee.” Norris v. Sec. & Exch. Comm’n,
675 F.3d 1349, 1355 (Fed. Cir. 2012). Thus, when review-
ing an agency’s decision to take adverse action against an
employee, the arbitrator must “independently assess[] the
relevant Douglas factors to determine whether the penal-
ty imposed was reasonable.” Id. at 1357.
    The Douglas factor at issue here is the “consistency of
the penalty with those imposed upon other employees for
the same or similar offences.” 5 M.S.P.R. at 305. To
establish disparate penalties, the employee must show
“that the charges and the circumstances surrounding the
charged behavior are substantially similar,” which in-
cludes “proof that the proffered comparator was in the
same work unit, with the same supervisor, and was
subjected to the same standards governing discipline.”
Lewis v. Dep’t of Veterans Affairs, 113 M.S.P.R. 657, 660
(2010) (Lewis II). “Where an employee raises an allega-
tion of disparate penalties in comparison to specified
employees, the agency must prove a legitimate reason for
the difference in treatment by a preponderance of the
evidence.” Lewis v. Dep’t of Veterans Affairs, 111 M.S.P.R.
388, 391 (2009) (Lewis I). Moreover, “evidence regarding
similarly-situated employees who received no discipline
after committing similar misconduct would also support
MISKILL   v. SSA                                          7



[a] disparate penalty claim.” Fearon v. Dep’t of Labor, 99
M.S.P.R. 428, 434 (2005).
    Here, Ms. Miskill was removed in August 2013 for vio-
lations of the time and attendance policy from 2011–2013.
At her arbitration hearing, Ms. Miskill presented evi-
dence that her entire department committed the same or
similar offenses during the same time period, yet no other
employee had been disciplined. The government did not
directly confront that evidence but merely argued that,
because the eight other employees in the DNE were
currently under investigation and had not yet been
charged, they could not be considered comparator employ-
ees. J.A. 234. The Arbitrator agreed and sustained Ms.
Miskill’s removal after finding that “the eight compara-
tors were [not] similarly situated to [Ms. Miskill] be-
cause . . . the possible disciplinary action regarding these
other employees is still pending an investigation.” J.A. 4.
As we have noted, this was in error.
    A comparator is an employee that “was in the same
work unit, with the same supervisor, and was subjected to
the same standards governing discipline.” Lewis II, 113
M.S.P.R. at 660. There is no strict requirement that
employees subject to the same standards governing
discipline must always receive precisely the same penalty.
But similarly situated employees must be subject to the
same criteria, and differences in penalties must depend
on specific factual differences between those employees.
That consideration is, by its nature, a case-dependent,
highly factual inquiry and not amenable to bright-line
rules.
    Here, the Arbitrator erred by imposing a categorical
rule of exclusion, i.e., that similarly situated employees
under investigation could not be comparators. It is true
that, in some circumstances, an ongoing investigation
may be a legitimate basis to exclude an employee as a
comparator. But that depends on the factual circum-
8                                             MISKILL   v. SSA



stances. Here, the facts strongly suggest that it was
improper to exclude the eight employees as comparators
simply because they were under investigation at the time
of the arbitration. After Ms. Miskill’s removal in Septem-
ber 2013, the Agency knew or should have known that
there were potential problems with the implementation of
time and attendance polices in the DNE unit. Yet the
Agency waited to begin its investigation of the eight other
DNE employees for almost two years and, in fact, did not
initiate an investigation until it discovered that
Ms. Miskill was alleging disparate treatment.
    The time required for the Agency to perform its inves-
tigation once begun also suggests that it was improper to
exclude the eight employees as comparators based simply
on their investigation status. Ms. Miskill’s supervisor
received an anonymous tip that Ms. Miskill may have
violated the agency’s time and attendance policies. Less
than two months had elapsed from receipt of that tip until
completion of an investigation and the issuance of a
Notice of Proposed Removal. But the investigation into
the other eight employees had not finished by the time
the Arbitrator issued his opinion, which was more than
six months after Ms. Miskill submitted her evidence
regarding the time and attendance violations of the other
employees to the Agency in June 2015. This was true,
moreover, despite the fact that the Agency had access to
Ms. Dayton’s detailed analysis of the time records, which
provided a starting point for the Agency’s own investiga-
tion of those employees. Thus, even putting the initial
two-year lag time aside, there is no explanation for such
an additional delay.
     Although the Agency’s timing could be read to suggest
that it placed—and kept—the comparators under investi-
gation for the sole purpose of evading Ms. Miskill’s dis-
parate treatment allegation, we need not ascribe any
particular motivation to the Agency or require any proof
of intent to conclude that the Arbitrator erred in categori-
MISKILL   v. SSA                                         9



cally excluding these eight employees as comparators.
The Agency’s conduct here is made even more troubling
by its concession at oral argument that upon completion
of the investigation, the Agency did not discipline six of
the DNE employees and counseled the remaining two.
Oral Argument at 13:50–14:18 http://oralarguments.cafc.
uscourts.gov/default.aspx?fl=2016-1598.mp3.      In short,
the Agency determined that removal was the appropriate
penalty for Ms. Miskill, but no other similar adverse
action was warranted for the eight other employees who
committed the same or similar violations. This type of
factual evidence is why a categorical rule of exclusion
based on an employee’s investigatory status is improper.
    To be clear, we are not creating an opposite categori-
cal rule—that consideration of an ongoing investigation is
never relevant to the question of consistency of punish-
ment. Nor do we implicitly hold that punishment of one
employee cannot occur until all possible investigations of
all potential employees have been completed. Such rules
would be unworkable. Rather, when a particular employ-
ee under investigation is raised as a comparator, the
arbitrator must evaluate that as one factor, among others,
to determine the consistency of the agency punishment.
    On remand, if the Arbitrator determines that any or
all of the eight DNE employees are comparators, then he
must determine if the Agency imposed consistent penal-
ties. 1 See Douglas, 5 M.S.P.R. at 305; see also Fearon, 99
M.S.P.R. at 434. Although “penalty decisions have gener-
ally looked backward to determine if the penalty selected
by the agency is consistent with those which have been
historically imposed by the agency,” under certain cir-


   1   The evidence regarding the eight comparators
may be relevant to other Douglas factors, but we leave
this question to the Arbitrator to consider in the first
instance.
10                                            MISKILL   v. SSA



cumstances, the consideration of post-removal evidence is
appropriate. Chavez v. Small Bus. Admin., 121 M.S.P.R.
168, 182 n.7 (2014). Given the Agency’s conduct in this
case, if the Arbitrator determines that any or all of the
eight other employees are comparators, the Arbitrator
should reopen the record to compare the penalties im-
posed upon the comparators with Ms. Miskill’s penalty of
removal. 2
                             III
    Because the Arbitrator erred in the comparator em-
ployee analysis, we vacate and remand. On remand, if
the Arbitrator determines that any or all of the eight
DNE employees are comparators, the Arbitrator is in-
structed to reopen the record to determine if the penalties
imposed upon the comparators were consistent with the
penalty received by Ms. Miskill.
              VACATED AND REMANDED
     Costs to Petitioners.




     2  This is not the end of the analysis, however. If the
Arbitrator determines that the comparators were treated
differently, the burden shifts to the Agency to prove a
legitimate reason for the differing treatment. See Lewis I,
111 M.S.P.R. at 391.
