OPINION OF THE COURT
After Appellant James McCutchen suffered a serious automobile accident, a benefit plan administered by US Airways paid $66,866 for his medical expenses. McCutchen then recovered $110,000 from third parties, with the assistance of counsel. Then US Airways, which had not sought to enforce its subrogation rights, demanded reimbursement of the entire $66,866 it had paid without allowance for McCutchen’s legal costs, which had reduced his net recovery to less than the amount it demanded. US Airways filed this suit against McCutchen for “appropriate equitable relief’ pursuant to § 502(a)(3) of the Employee Retirement Income Security Act of 1974, as amended (“ERISA”), 29 U.S.C. § 1132(a)(3)(B). The issue before us is whether McCutchen may assert certain equitable limitations, such as unjust enrichment, on US Airways’ equitable claim. We conclude that he may. *673 We therefore vacate the District Court’s order requiring McCutchen to pay US Airways the entire $66,866 and remand the case for that Court to fashion “appropriate equitable relief.”
I.
This case stems from a tragic car accident in which a young driver lost control of her car, crossed the median of the road, and struck a car driven by 51-year-old James McCutchen. Then the truck traveling behind McCutchen also slammed into his car. The accident killed one person and left two others with severe brain injuries. McCutchen himself was grievously injured and survived only after emergency surgery. He spent several months in physical therapy and ultimately underwent a complete hip replacement. Since the accident, McCutchen, who had a history of back surgeries and associated chronic pain, has also become unable to effectively treat that pain with medication. The accident has rendered him functionally disabled. McCutchen’s Health Benefit Plan (the “Plan”), administered and self-financed by US Airways, paid medical expenses in the amount of $66,866 on his behalf.
After the accident, McCutchen, through his attorneys at Rosen Louik & Perry, P.C., filed an action against the driver of the car that caused the accident. Because she had limited insurance coverage, and because three other people were seriously injured or killed, McCutchen settled with the other driver for only $10,000. However, with his lawyers’ assistance, he and his wife received another $100,000 in underinsured motorist coverage for a total third-party recovery of $110,000. After paying a 40% contingency attorneys’ fee and expenses, his net recovery was less than $66,000. US Airways demanded reimbursement for the entire $66,866 that it had paid for McCutchen’s medical bills. Soon after, Rosen Louik & Perry placed $41,500 in a trust account, reasoning that any lien found to be valid would have to be reduced by a proportional amount of legal costs. The record on appeal does not establish what amount was disbursed to McCutchen.
When McCutchen did not pay, US Airways, in its capacity as administrator of the ERISA benefits plan, filed suit in the District Court under § 502(a)(3) of ERISA, seeking “appropriate equitable relief’ in the form of a constructive trust or an equitable lien on the $41,500 held in trust and the remaining $25,366 personally from McCutchen. The Summary Plan Description describing the US Airways benefits plan covering McCutchen contained the following paragraph, entitled “Subrogation and Right of Reimbursement”:
The purpose of the Plan is to provide coverage for qualified expenses that are not covered by a third party. If the Plan pays benefits for any claim you incur as the result of negligence, willful misconduct, or other actions of a third party, the Plan will be subrogated to all your rights of recovery. You will be required to reimburse the Plan for amounts paid for claims out of any monies recovered from a third party, including, but not limited to, your own insurance company as the result of judgment, settlement, or otherwise. In addition you will be required to assist the administrator of the Plan in enforcing these rights and may not negotiate any agreements with a third party that would undermine the subrogation rights of the Plan.
(App.117) (emphasis added). Thus, under the Plan Description, a beneficiary is required to reimburse the Plan for any amounts it has paid out of any monies the beneficiary recovers from a third party.
*674 US Airways claims that this language permits it to recoup the $66,866 it provided for McCutchen’s medical care out of the $110,000 total that he recovered regardless of his legal costs. It argues that “[t]he Plan language specifically authorized reimbursement in the amount of benefits paid, out of any recovery.” (Appellee’s Br. at 15-16).
McCutchen says that it would be unfair and inequitable to reimburse US Airways in full when he has not been fully compensated for his injuries, including pain and suffering. He argues that US Airways, which made no contribution to his attorneys’ fees and expenses, would be unjustly enriched if it were now permitted to recover from him without any allowance for those costs, in essence to reap what McCutchen has sown. Indeed, if legal costs are not taken into account, US Airways will effectively be reaching into its beneficiary’s pocket, putting him in a worse position than if he had not pursued a third-party recovery at all.
Citing the Plan’s use of the language “any monies recovered,” as well as our previous decisions, the District Court rejected McCutchen’s arguments and granted summary judgment to US Airways. The Court required McCutchen to sign over the $41,500 held in trust and to pay $25,366 from his own funds. McCutchen appeals. 1
II.
A.
Congress designed ERISA to protect employee pensions and benefits by providing pension insurance, enumerating certain specific characteristics of pension and benefit plans, and setting forth fiduciary duties for the managers of both pension and nonpension plans.
Varity Corp. v. Howe,
The Supreme Court has explained that the modifier “appropriate equitable relief’ is not superfluous.
Mertens,
The Supreme Court has twice considered what this limitation means in the context of a fiduciary’s action for reimbursement from a beneficiary under an ERISA plan. In
Great-West Life & Annuity Insurance Co. v. Knudson,
the Court first considered whether an ERISA plan administrator’s claim for reimbursement was equitable in nature.
See
In
Sereboff v. Mid Atlantic Medical Services, Inc.,
the Court again considered an ERISA plan administrator’s claim for reimbursement under the terms of the plan and § 502(a)(3).
See
This case squarely presents the question that Sereboff left open: whether § 502(a)(3)’s requirement that equitable relief be “appropriate” means that a fiduciary like US Airways is limited in its recovery from a beneficiary like McCutch *676 en by the equitable defenses and principles that were “typically available in equity.”
B.
McCutchen argues that the phrase “appropriate equitable relief’ means more than just that the relief US Airways seeks must be of an equitable type; courts must also exercise their discretion to limit that relief to what is “appropriate” under traditional equitable principles. In particular, he argues that the principle of unjust enrichment frames US Airways’ claim. We agree. 2
The Supreme Court reasoned in
Knudson
that “ ‘equitable relief must mean
something
less than
all
relief.”
Knudson,
Indeed, it would be strange for Congress to have intended that relief under § 502(a)(3) be limited to traditional equitable categories, but not limited by other equitable doctrines and defenses that were traditionally applicable to those categories. “[Statutory reference to [an equitable] remedy must, absent other indication, be deemed to contain the limitations upon its availability that equity typically imposes.”
Knudson,
To determine what types of relief were typically available in equity, the Supreme Court endorsed consultation of “standard current works such as Dobbs, Palmer, Corbin, and the Restatements, which make the answer clear.”
Knudson,
C.
Against this conclusion, US Airways cites to prior decisions of this Court in which we declined to fashion a federal common law rule limiting an ERISA plan administrator’s right to reimbursement under the plan’s terms.
See Ryan ex rel. Capria-Ryan v. Fed. Express,
*678
US Airways next cites cases from other Courts of Appeals, some of which were decided after
Sereboff,
to support its position that equitable doctrines that might limit its reimbursement recovery are not applicable under § 502(a)(3).
See Zurich Am. Ins. Co. v. O’Hara,
We disagree with those circuits that have held that it would be pioneering federal common law to apply equitable limitations on an equitable claim. Congress purposefully limited the relief available to fiduciaries under § 503(a)(3) to “appropriate equitable relief.”
See Knudson,
Moreover, as the Supreme Court recently demonstrated in
CIGNA,
the importance of the written benefit plan is not inviolable, but is subject — based upon equitable doctrines and principles — to modification and, indeed, even equitable reformation under § 502(a)(3).
Thus, we agree that one of Congress’s purposes in enacting ERISA was to “ensure the integrity of written, bargained-for benefit plans.’ ”
O’Hara,
Finally, US Airways raises a practical concern that the application of equitable principles will increase plan costs and premiums. This concern does not address the statutory language and is, in any event, unsubstantiated by the circumstances of this case. US Airways cannot plausibly claim it charged lower premiums because it anticipated a windfall.
D.
Applying the traditional equitable principle of unjust enrichment, we conclude that the judgment requiring McCutchen to provide full reimbursement to US Airways constitutes inappropriate and inequitable relief. Because the amount of the judgment exceeds the net amount of McCutchen’s third-party recovery, it leaves him with less than full payment for his emergency medical bills, thus undermining the entire purpose of the Plan. At the same time, it amounts to a windfall for US Airways, which did not exercise its subrogation rights or contribute to the cost of obtaining the third-party recovery. Equity abhors a windfall.
See Prudential Ins. Co. of America v. S.S. American Lancer,
Therefore, we will vacate the District Court’s final judgment. We do not decide on appeal what
would
constitute appropriate equitable relief for US Airways because “equity calls for full factual findings rather than our speculation.”
Nat’l City Mortg. Co. v. Stephen,
On remand, the District Court should engage in any additional fact-finding it finds necessary. In addition to the considerations discussed above, factors such as the distribution of the third-party recovery between McCutchen and his attorneys at Rosen Louik & Perry, the nature of their agreement, the work performed, and the allocation of costs and risks between the parties to this suit may inform the Court’s exercise of its discretion to fashion “appropriate equitable relief.”
*680 III.
Because we conclude that US Airways’ claim for reimbursement under § 502(a)(3) of ERISA is subject to equitable limitations, we will vacate the District Court’s final judgment and remand for further proceedings consistent with this opinion.
Notes
. The District Court had jurisdiction over this matter under 28 U.S.C. § 1331 and 29 U.S.C. § 1132(e)(1). We have jurisdiction over McCutchen’s appeal under 28 U.S.C. § 1291. "We exercise plenary review over a district court’s summary judgment ruling.”
Disabled in Action of Pa. v. Se. Pa. Transp. Auth.,
. Before the District Court, McCutchen also argued for application of the “make-whole” doctrine, which is an equitable doctrine, applied in many states, that provides that "the insured is entitled to be made whole before the insurer recovers on its subrogation claim.” 16 Lee R. Russ in conjunction with Thomas F. Segalla,
Couch on Insurance
§ 223:133 (3d ed. 2011);
see, e.g., Swanson v. Hartford Ins. Co. of Midwest,
. Even under our prior cases, US Airways' claim to reimbursement from McCutchen's pocket is unprecedented. We declined to pass on the permissibility of such a claim in
Bollman Hat,
where
amicus
contended that mechanically enforcing a plan’s reimbursement terms "will lead to inequitable results where a plan participant’s third party recovery is less than the plan's subrogation claim plus attorney’s fees.”
