 United States Court of Appeals
         FOR THE DISTRICT OF COLUMBIA CIRCUIT



Argued March 23, 2018                   Decided July 17, 2018

                         No. 17-7138

                      RONALD E. PECK,
                        APPELLANT

                              v.

  SELEX SYSTEMS INTEGRATION, INC. AND SELEX SISTEMI
 INTEGRATI, INC. KEY EMPLOYEE DEFERRED COMPENSATION
                         PLAN,
                       APPELLEES


        Appeal from the United States District Court
                for the District of Columbia
                    (No. 1:13-cv-00073)


    William R. Wilder argued the cause and filed the briefs for
appellant.

    Timothy A. Hilton argued the cause for appellees. With
him on the brief were Julianne P. Story, Michael T. Raupp, and
Steven A. Neeley.

   Before: HENDERSON and SRINIVASAN, Circuit Judges, and
EDWARDS, Senior Circuit Judge.

    Opinion for the Court filed by Circuit Judge SRINIVASAN.
                                2
     SRINIVASAN, Circuit Judge: After working at SELEX
Systems Integration, Inc. for over fifteen years, Ronald Peck
was terminated for refusing to transfer to a different position in
the company. He filed separate claims for benefits under
SELEX’s deferred-compensation plan and its severance policy.
Both claims were denied on the same ground: that Peck’s
termination for refusing to transfer positions rendered him
ineligible for benefits.

    Peck filed suit against SELEX and its Key Employee
Deferred Compensation Plan (together, SELEX), alleging that
the denial of benefits violated the Employee Retirement
Income Security Act of 1974 and breached SELEX’s
contractual duty to provide severance pay to eligible
employees. The district court granted judgment in SELEX’s
favor on both the deferred-compensation claim and the
severance-pay claim. We vacate the district court’s judgment
with regard to deferred compensation but affirm with regard to
severance pay.

                                I.

     For over fifteen years, Ronald Peck worked at SELEX
Systems Integration, an international company that designs and
produces aviation navigation, defense, and surveillance
systems for governments, militaries, and industrial operators.
Peck began his tenure with SELEX as the Director of Quality
at the company’s U.S. headquarters in Overland Park, Kansas.
Peck rose through the ranks of the quality department over the
next eleven years, eventually assuming the role of Vice
President of Quality and Engineering.

    Peck transitioned away from quality-control positions in
conjunction with SELEX’s implementation of a five-year plan
to expand its U.S. market. In March 2008, Peck became the
Vice President of Business Development, responsible for all
                                3
marketing and sales in the U.S. market. Two years later,
SELEX opened an office in Washington, D.C., to establish a
presence near the Federal Aviation Administration and other
D.C.-based clients. In connection with the opening, Peck
became Vice President of Strategy and Product Planning,
another marketing role. For the first year in the new position,
Peck traveled frequently between Kansas and D.C. In October
2011, Peck moved to D.C. full time, and in February 2012, he
officially transferred to the company’s D.C. office.

     On August 23, 2012, SELEX’s Chief Executive Officer,
Mike Warner, held a meeting with Peck. Warner informed
Peck that he was being removed from the marketing position
in D.C. due to poor performance. Warner offered Peck the
option to transfer back to the Kansas office and assume the
position of Vice President of Quality Control and Business
Improvement. Warner memorialized the offer in a letter to
Peck dated August 29, 2012. The letter confirmed that Peck’s
removal from the “marketing leadership role” resulted from
“recurring deficiencies in [his] performance” that could have
“jeopardize[d] the continued success of the company’s
business initiatives.” J.A. 86. The letter said that the company
therefore “need[ed Peck] to transfer immediately back to
Overland Park to assume the [quality-control] position,” which
was “well suited to [his] expertise.” Id.

     After initially declining Warner’s offer on the telephone,
Peck confirmed his decision in a letter dated September 3,
2012. Peck explained in the letter that the new position was
“not an equivalent position to [his] current role,” did not
“represent a logical step in [his] career progression,” and
“would . . . effectively [have] be[en] a regression in [his] career
with the Company.” J.A. 87. Peck nonetheless expressed his
willingness to continue in the D.C. marketing position.
                                4
     Warner responded in a letter dated September 14, 2012,
explaining that there was no longer a position for Peck in D.C.
Warner sought to assure Peck that the new position was not a
“regression” because Peck would report directly to Warner and
take on the new responsibility of directly supervising others.
J.A. 88. Warner thus urged Peck to “reconsider [his] refusal to
accept [the] new assignment” within two weeks. J.A. 89.
Warner expressed that Peck’s refusal to do so “would
constitute ‘cause’” for his termination. Id. Although Peck, as
an at-will employee, could be terminated without cause, a for-
cause termination would affect his eligibility for certain
deferred-compensation and severance benefits.

    Peck and Warner exchanged a few more letters, with Peck
maintaining that his refusal to accept the quality-control
position could not be considered “cause” for his discharge, and
Warner maintaining the opposite stance. On September 30,
2012, Warner terminated Peck’s employment with SELEX,
and his marketing responsibilities were distributed among
Warner and two D.C. consultants.

    After Peck’s termination, he submitted a claim for benefits
under SELEX’s “Key Employee Deferred Compensation
Plan.” Peck had joined the Plan as a “Key Employee” in July
2008, when serving as the Vice President of Business
Development.        The Plan is an unfunded, deferred-
compensation plan. The Plan is of a type described as a
“top-hat plan,” in that it allows employers to provide retirement
benefits to select employees in excess of the benefits provided
under typical retirement plans. See 29 U.S.C. § 1051(2).

    Under the Plan, Peck’s entitlement to benefits would
ordinarily vest after five years of participation in the Plan. The
Plan provided, however, that his right would vest before five
years if, among other reasons, he was terminated by SELEX
                               5
without cause. As relevant here, the Plan defines “cause” as an
employee’s “habitual neglect of or deliberate or intentional
refusal to perform any of his or her material duties and
obligations of his or her employment (including compliance
with the Company’s Code of Conduct) with the Company.”
J.A. 59.

     According to the Plan’s terms, the Administrative
Committee has “discretionary authority and responsibility to
interpret and construe the Plan” and to determine whether
employees are eligible for payouts under the Plan. J.A. 67.
Here, the Committee, composed at the time of CEO Warner,
the Chief Financial Officer, and the Human Resources
Director, denied Peck’s claim for benefits after concluding that
he had been terminated for cause. In the Committee’s view,
Peck’s “voluntary refusal of the assignment to the position of
Vice President of Quality Control and Business Improvement”
was a “deliberate or intentional refusal to perform any material
duties and obligations of [his] employment.” J.A. 95-96. Peck
administratively appealed the decision, but the Committee
again denied his claim.

     Peck separately sought benefits under SELEX’s severance
policy. See J.A. 79. Under the policy, SELEX agreed to
provide “separation benefits” to eligible full-time employees
“whose employment terminates due to lack of work,
elimination of position, or change of control.” Id. The policy
further provided that an employee discharged for one of the
three enumerated reasons would nonetheless be ineligible for
severance pay if terminated for cause. Id. For eligible high-
level employees who had worked at the Company for over ten
years, SELEX would pay nine months of severance benefits
under the Policy. In response to Peck’s claim under the
severance policy, SELEX stated that he was ineligible for
                               6
severance pay “[g]iven the circumstances of the termination of
[his] employment.” J.A. 92.

    Peck filed a suit against SELEX in D.C. Superior Court.
He raised three contract claims: one for severance pay in the
amount of $151,549; a second for deferred-compensation
benefits in the amount of $57,020; and a third for relocation
expenses in the amount of $21,195. SELEX removed the case
to federal district court and moved to dismiss Peck’s
deferred-compensation claim, arguing that the claim was
preempted by the Employee Retirement Income Security Act
(ERISA). In response, Peck voluntarily dismissed the claim
and, with leave from the district court, filed an amended
complaint that added the Key Employee Deferred
Compensation Plan as a defendant and pled the deferred-
compensation claim as one arising under ERISA.

     SELEX moved for summary judgment on Peck’s
deferred-compensation claim, and Peck moved for summary
judgment on all three of his claims. The district court granted
SELEX’s motion, holding that the Plan’s Administrative
Committee reasonably determined that Peck’s refusal to
transfer positions constituted cause for termination, thus
rendering Peck ineligible for deferred compensation under the
Plan. See Peck v. SELEX Sys. Integration, Inc. (Peck I), 172 F.
Supp. 3d 171, 176-78 (D.D.C. 2016). The court also denied
Peck’s motion for reconsideration. See Peck v. SELEX Sys.
Integration, Inc. (Peck II), 270 F. Supp. 3d 107, 116-17
(D.D.C. 2017).

     As for the remaining two claims, the district court found
that there were genuine issues of material fact precluding
summary judgment, so the parties proceeded to a bench trial.
Following trial, the district court ruled in Peck’s favor on the
                               7
claim for relocation expenses. Peck II, 270 F. Supp. 3d at 115-
16. That claim is not at issue in the appeal now before us.

     The district court entered judgment in favor of SELEX on
the severance claim. The court reasoned that, to collect
payment under SELEX’s Separation Policy, Peck needed to
show that he was terminated for one of the three enumerated
reasons: “lack of work, elimination of position, or change in
control.” Id. at 115. The parties agreed that the sole issue in
the circumstances presented was whether Peck was discharged
due to the elimination of a position. The district court found
that the evidence “clearly show[ed] that Peck was terminated
because he would not return to Kansas to serve in a different
capacity, not because SELEX was eliminating the marketing
position in D.C.” Id. As a result, the court held that Peck had
not shown he was entitled to severance pay. Id.

                               II.

    On appeal, Peck challenges the district court’s entry of
judgment against him on his deferred-compensation and
severance-pay claims. We agree with Peck as to deferred
compensation but disagree as to severance pay.

                               A.

     Peck argues that SELEX acted unreasonably in
determining that he was terminated for cause and was thus
ineligible to receive deferred-compensation benefits. The
company responds that Peck’s refusal to accept the offer of a
new position amounted to cause for his termination under the
terms of its deferred-compensation plan. We agree with Peck’s
understanding: his refusal to accept a transfer to a new position
could not reasonably be considered cause for terminating him.
                               8
                               1.

     At the outset, the parties disagree about the standard of
review governing our consideration of Peck’s challenge. We
generally review de novo the district court’s determination of
an ERISA claim on summary judgment. Marcin v. Reliance
Standard Life Ins. Co., 861 F.3d 254, 262 (D.C. Cir. 2017). We
therefore apply the same standard that governed the district
court’s review of the ERISA plan administrator’s challenged
determination—here, the determination by the Plan’s
Administrative Committee to deny Peck benefits. See id. The
courts of appeals, though, have adopted differing positions on
the standard a district court should apply when reviewing a
determination made by an administrator of a top-hat plan like
the one at issue here. For the following reasons, we have no
need in this case to decide between the competing approaches.

     By way of background, ERISA is silent on the standard
that courts should use when reviewing a benefits determination
made by the administrator of an ERISA plan. The Supreme
Court addressed that issue in Firestone Tire & Rubber Co. v.
Bruch, 489 U.S. 101 (1989). Relying on principles from trust
law, the Court held that “a denial of benefits challenged under
§ 1132(a)(1)(B) is to be reviewed under a de novo standard
unless the benefit plan gives the administrator or fiduciary
discretionary authority to determine eligibility for benefits or
to construe the terms of the plan.” Id. at 115. If a plan grants
the administrator or fiduciary such authority, “a deferential
standard of review [is] appropriate.” Id. at 111. We have
described that “deferential” standard as review for
“reasonableness.” Wagener v. SBC Pension Benefit Plan—
Non Bargained Program, 407 F.3d 395, 402 (D.C. Cir. 2005).

    The courts of appeals have reached different conclusions
on whether Firestone’s deferential standard of review applies
                                9
in the case of a top-hat plan that grants the plan administrator
discretion to interpret the plan’s terms. Some courts have
declined to apply Firestone’s deferential standard in that
context because of certain unique qualities of top-hat plans,
including their general exemption from ERISA’s fiduciary
requirements. See Craig v. Pillsbury Non-Qualified Pension
Plan, 458 F.3d 748, 752 (8th Cir. 2006); Goldstein v. Johnson
& Johnson, 251 F.3d 433, 442-44 (3d Cir. 2001). Other courts
apply Firestone’s deferential standard to top-hat plans that vest
administrators with discretion to interpret the plan’s
provisions. See Comrie v. IPSCO, Inc., 636 F.3d 839, 842 (7th
Cir. 2011); Sznewajs v. U.S. Bancorp Amended & Restated
Supp. Benefits Plan, 572 F.3d 727, 733-34 (9th Cir. 2009),
overruled in part on other grounds by Salomaa v. Honda Long
Term Disability Plan, 642 F.3d 666, 673-74 (9th Cir. 2011);
Paneccasio v. Unisource Worldwide, Inc., 532 F.3d 101, 108
(2d Cir. 2008). It bears noting that, while the courts expressly
disagree about the governing standard, e.g., Comrie, 636 F.3d
at 842, the extent to which the competing approaches result in
a practical difference may be open to some question: even the
courts to reject Firestone’s deferential standard still ultimately
ask “whether the Plan’s decision was reasonable.” Craig, 458
F.3d at 752; see Goldstein, 251 F.3d at 444.

    At any rate, we have no need in this case to explore the
varying approaches or to choose between them. As we explain
next, even assuming Firestone’s deferential standard of review
applies in the context of this case, SELEX’s denial of Peck’s
claim for deferred compensation still cannot be sustained as a
reasonable determination under the company’s plan.

                               2.

    Under SELEX’s Key Employee Deferred Compensation
Plan, an employee’s entitlement to benefits vested after an
                              10
initial period of five years from the Plan’s establishment. But
an employee’s right to deferred compensation vested before
five years if he was terminated without cause. Because Peck
was discharged within five years of the Plan’s establishment,
his eligibility for benefits turns on whether his termination
could be considered one for “cause” under the terms of the
Plan.

     “Cause” for termination, the Plan provides, arises from an
employee’s “habitual neglect of or deliberate or intentional
refusal to perform any of his or her material duties and
obligations of his or her employment (including compliance
with the Company’s Code of Conduct) with the Company.”
J.A. 59. The Plan’s Administrative Committee determined that
Peck’s refusal to accept the quality-control position afforded
cause for terminating him under that definition. While the
company offered no explanation of its interpretation at the time
of the decision, it now explains that Peck was an at-will
employee without any employment contract assigning him to a
specific position or specific duties. Thus, the company
maintains, the “material duties and obligations of [Peck’s]
employment . . . with the Company” amounted to whatever
duties he was directed to perform, including the direction to
assume an entirely different position, with entirely different
duties, in an entirely different locale (Kansas instead of
Washington, D.C.). And by refusing to accept the new
position, SELEX asserts, Peck engaged in a “refusal to
perform” the “material duties and obligations” of his
employment with the company.

    SELEX’s interpretation of the Plan cannot be correct. Its
reading is incompatible with the terms of the Plan and upsets
the parties’ reasonable expectations about the duties of a
person’s employment with the company. See Wagener, 407
F.3d at 404-05; see also Shelby Cty. Health Care Corp. v. S.
                               11
Council of Indus. Workers Health & Welfare Trust Fund, 203
F.3d 926, 934 (6th Cir. 2000) (“[A] plan administrator must
adhere to the plain meaning of [a plan’s] language, as it would
be construed by an ordinary person.”). Under SELEX’s
interpretation, an at-will employee’s “material duties and
obligations” would be entirely unconnected to his or her
current position. So a high-level manager, for instance, would
give the company cause to terminate her if she declined to
move across the country to perform an entirely different (and
less desirable) role (perhaps in a much lower-ranking position
on the organizational chart).

     Although the literal terms “employment with the
company” in theory could encompass any position at all in the
company, the surrounding words foreclose that unnatural
reading. The phrase “material duties and obligations of [a
person’s] employment” naturally refers to the set of
responsibilities assigned to an employee.           And those
responsibilities are necessarily tied to an employee’s position
with the company. To avoid for-cause dismissal, then, an
employee cannot refuse to fulfill the duties and obligations
assigned to her, which means she cannot refuse to carry out the
duties of the position she holds. But she does not “refuse to
perform the material duties and obligations of her employment
with the company” if she declines to accept materially different
duties and obligations.

     Peck, consequently, did not refuse to perform the material
duties and obligations of his employment with the company.
After SELEX determined that he was unlikely to succeed in the
D.C. marketing position he held, he was offered the
opportunity to assume a different position in the quality-control
department in Kansas. The offer involved a new set of
“material duties and obligations.” In his marketing position, he
oversaw all marketing and sales for the U.S. market, and he had
                               12
no duties related to quality control. The Kansas position, by
contrast, involved supervising a team tasked with improving
the quality of SELEX’s products and services. Peck’s refusal
to accept that new position was not a “refusal to perform the
material duties and obligations of his employment.”

     SELEX argues that the parenthetical clause in the “cause”
definition—i.e., “material duties and obligations of his or her
employment (including compliance with the Company’s Code
of Conduct)”—shows that a person’s duties go beyond her
specific position.     The parenthetical clause, however,
establishes only that an employee’s material duties and
obligations include adherence to the Code of Conduct. The fact
that the Code of Conduct applies to all positions in the
company does not somehow expand a particular employee’s
scope of assignable duties to encompass the duties of every
position throughout the company.

    Finally, SELEX, in a footnote in its brief, suggests that we
should defer to the Administrative Committee’s finding that
Peck waived his deferred-compensation claim when he
voluntarily dismissed his state-law claim raising that issue (and
substituted the ERISA claim we now consider). We decline to
consider SELEX’s conclusory assertion of waiver, offered
without supporting argument, discussion, or legal authority.
See Washington Legal Clinic for the Homeless v. Barry, 107
F.3d 32, 39 (D.C. Cir. 1997).

     In sum, we hold that Peck did not refuse to perform the
duties of his employment with the company when he declined
to assume the different duties of a different position in a
different location. SELEX’s termination of him therefore
could not have reasonably qualified as a termination for cause
within the meaning of the Plan, meaning that Peck is entitled
to deferred compensation under the Plan. See Wagener, 407
                               13
F.3d at 405 (“Plan fiduciaries cannot claim deference for an
interpretation of the Plan that . . . contradicts the Plan’s plain
language.”).

                               B.

    We turn now to Peck’s claim for severance pay under
SELEX’s Separation Policy.         The Policy provided for
severance pay to a full-time employee “whose employment
terminates due to lack of work, elimination of position, or
change of control.” J.A. 79. Peck asserts an entitlement to
severance pay based solely on the second of those grounds: he
contends that SELEX terminated him because it eliminated his
marketing position.

      The district court concluded otherwise. Following a bench
trial, the district court found that “Peck was terminated because
he would not return to Kansas to serve in a different capacity,
not because [SELEX] was eliminating the marketing position
in D.C.” Peck II, 270 F. Supp. 3d at 115. To prevail on his
claim for severance pay, then, Peck needs to show that the
district court erred in finding that his termination resulted from
his refusal to accept the new position in Kansas and not from
an elimination of his position in D.C. See Overby v. Nat’l Ass’n
of Letter Carriers, 595 F.3d 1290, 1293-94 (D.C. Cir. 2010)
(factual findings not set aside unless “clearly erroneous”).

     Peck, however, at no point contests the district court’s
finding that he was terminated because he refused to accept the
quality-control position and not because of the elimination of
his position. Instead, he argues that the district court erred in
finding that SELEX did not eliminate his marketing position.
Peck contends that the marketing position in fact was
eliminated. But that argument, even if persuasive, does not
suffice to establish Peck’s entitlement to severance pay.
Regardless of whether the company eliminated Peck’s
                              14
marketing position, he would still need to show that he was
terminated because of the position’s elimination rather than
solely because of his refusal to accept the quality-control
position. Yet Peck raises no challenge to the district court’s
finding that his termination resulted from his refusal to accept
the new position and not from an elimination of his marketing
position. Indeed, SELEX, in its brief, specifically pointed to
Peck’s failure to raise such a challenge, but Peck still did not
address the issue in his reply brief.

    Peck alternatively argues that SELEX should be estopped
from claiming that Peck was terminated for a reason other than
the elimination of position. Prior to the litigation, Peck
contends, SELEX rested its denial of severance benefits on the
ground that he refused to transfer to the quality-control
position. According to Peck, SELEX now takes what he
perceives to be a different position: that he is ineligible for
severance pay because his termination was not due to an
elimination of his position.

     Peck’s argument lacks merit. The doctrine of estoppel can
prelude a party from switching positions on an issue if it would
prejudice the opposing party. See Ward v. Wells Fargo Bank,
N.A., 89 A.3d 115, 126 (D.C. 2014); cf. Konstantinidis v. Chen,
626 F.2d 933, 938 (D.C. Cir. 1980) (discussing the concept of
judicial estoppel). SELEX, however, has not changed its tune
on the reason for denying Peck severance pay. In an October
2012 letter, SELEX’s CEO advised Peck that his “employment
with SELEX is terminated” “because you have continued to
refuse your assignment to the position of Vice President of
Quality Control and Business Improvement.” J.A. 92. SELEX
continues to maintain that Peck was terminated solely because
he refused to accept the new position. Peck’s estoppel
argument thus cannot carry the day.
                             15
                    * * * * *
    For the foregoing reasons, we vacate the district court’s
grant of summary judgment to SELEX on Peck’s
deferred-compensation claim and remand for entry of
judgment in Peck’s favor. We affirm the district court’s
judgment in SELEX’s favor on Peck’s claim for severance pay.

                                                 So ordered.
