ERISA reimbursement is the single most expensive lien category in California personal injury practice. It is also the one most plaintiff lawyers handle wrong — either by treating an ERISA reimbursement claim like any other health-plan subrogation request, or by giving up too easily on reduction arguments that the law actually permits.
This is the 2026 practitioner's guide. Not the academic version, not the carrier-friendly version. The version that gets settlements closed without leaving plaintiff money on the table.
Why ERISA plans are different
The Employee Retirement Income Security Act of 1974 preempts state law on most reimbursement questions for self-funded employer health plans. That preemption is the whole game. A health plan that would lose a reimbursement fight under California's anti-subrogation rule wins the same fight under ERISA's federal common law — and a plaintiff lawyer who tries to apply Howell reasoning or the make-whole doctrine to a self-funded ERISA plan usually loses on the law before the math even gets a hearing.
For the broader settlement-math primer, see how medical liens work in California. The ERISA piece sits in a different statutory universe, but it competes with the same recovery dollars at the same closing table.
Self-funded vs. fully-insured: the first question that matters
The first thing to learn about an ERISA reimbursement claim is whether the plan is self-funded or fully-insured. Self-funded plans are pure ERISA. The employer pays the claims directly out of its own assets and uses a third-party administrator to handle the paperwork. Federal common law governs the reimbursement question end-to-end.
Fully-insured plans are subject to state insurance regulation through ERISA's savings clause. In California, that means the anti-subrogation rule and the made-whole doctrine apply, and the reimbursement obligation is sharply curtailed in most settlement scenarios. Many large employer health plans look like ERISA plans on the front of the SPD but are in fact fully-insured arrangements with a major carrier. The distinction is dispositive.
Pull the Summary Plan Description. Pull the Form 5500. Look at Schedule A and Schedule C. If the plan reports premiums paid to an insurance company on Schedule A, the plan is at least partly fully-insured. If the plan reports only administrative fees on Schedule C, the plan is self-funded.
The plan-document fight
Even within self-funded ERISA, the reimbursement obligation lives in the plan document itself. A plan that does not contain a clear, conspicuous reimbursement clause does not have a reimbursement right, full stop. A plan that contains a reimbursement clause buried in the SPD but not in the underlying plan document may have a problem under CIGNA v. Amara, which held that the SPD is a summary, not the plan.
Demand the actual plan document, not the SPD, in writing. If the administrator stalls or refuses, that is your first pressure point. Federal courts have been receptive to the argument that a plan that will not produce its operative document cannot enforce a reimbursement clause it cannot prove existed at the time of the loss.
When the plan does produce the document, read the reimbursement section carefully. Is there an equitable-lien-by-agreement provision? Is there a constructive-trust clause? Is the reimbursement obligation tied to specifically identifiable settlement funds, or to general assets? After US Airways v. McCutchen and Montanile v. Board of Trustees, these clauses matter to whether the plan can reach the settlement at all.
Montanile and the dissipation defense
Montanile remains the single most useful Supreme Court decision for plaintiffs facing ERISA reimbursement demands. The holding is narrow but powerful: a plan that asserts an equitable lien by agreement under ERISA section 502(a)(3) can recover only from specifically identifiable settlement funds that remain in the beneficiary's possession. If the funds have been dissipated — spent on general living expenses, used to pay non-traceable obligations, commingled and consumed — the plan's equitable remedy is gone.
This is not a license to advise clients to dissipate. The plan can still assert a contract claim where the plan document permits, and federal common-law remedies vary. But it is a real defense that the plaintiff bar should preserve from the first settlement check. Talk to your client about commingling, about traceability, and about the practical math of writing the reimbursement check from the settlement proceeds before any disbursement that would dissipate the fund.
The common-fund and made-whole arguments under federal common law
Federal common law on ERISA reimbursement is not as plaintiff-friendly as California state law, but it is not empty. Two doctrines survive in negotiation and, in the right circuit, in litigation:
Common-fund — If the plaintiff's attorney created the fund from which the plan now seeks reimbursement, equity requires the plan to bear its share of the fee. Most plan documents now include language disclaiming the common-fund doctrine, and the Supreme Court in McCutchen held that clear plan language overrides the default. But many older plans still lack the disclaimer. Read the document. If the disclaimer is missing, the common-fund deduction is on the table.
Make-whole — Under federal common law, a plan that has not made its beneficiary whole cannot enforce reimbursement against partial settlement proceeds. Most plans now contract around this rule as well. When they do, the rule does not apply. When they do not, the make-whole argument is a genuine reduction theory at the negotiation table.
Neither doctrine is a slam dunk in 2026, but both remain useful pressure points when the plan document is silent or ambiguous.
The negotiation posture
Most ERISA reimbursement claims settle by negotiation, not by litigation. The administrator's incentive is to recover a defensible number quickly. The plaintiff's incentive is to keep enough recovery on the table to make the case worth closing. The realistic spread on most self-funded ERISA reductions is between thirty and sixty percent off billed reimbursement, depending on plan language, recovery size, and whether the case has a strong common-fund or make-whole argument.
Open with the plan-document demand. Use the response to gauge negotiating posture. Frame the reduction as a function of attorney's fees, costs, and the relative proportion of the recovery that the medical specials represent. Plans recognize the math. They will not give you the largest reduction, but they will give you a defensible one if the case is framed as a negotiation rather than a unilateral lien assertion.
What 2026 changed
Two developments since the start of the year matter to practitioners. First, the Ninth Circuit has continued to refine post-Montanile traceability doctrine in ways that favor plaintiffs who promptly disburse settlement proceeds through their attorney trust accounts to specific obligations. Second, several large self-funded administrators have updated their plan documents to add belt-and-suspenders language attempting to preserve reimbursement rights against dissipated funds — with mixed reception in the federal courts. Read every plan document fresh; the boilerplate from three years ago does not necessarily match what is on the books now.
For the closely-related state-side question on Medi-Cal liens and the Ahlborn process, see the companion piece in this series. For the operational layer on tracking lien exposure across an open caseload, see building a lien portfolio. For the broader provider-side question on whether to even accept lien-based treatment, the doctor-on-lien vetting checklist explains how plaintiff counsel evaluates the provider end of the same arrangement.
The one-paragraph checklist
On every PI matter where a client has employer-sponsored health coverage that paid for accident-related care: confirm self-funded vs fully-insured at intake. Demand the full plan document, not the SPD. Read the reimbursement and disclaimer language. Identify the common-fund and make-whole posture. Plan the disbursement around Montanile-style traceability. Open negotiation with a documented reduction theory rather than a plea for sympathy. Close at a defensible number that lets the case settle. The math does not have to be hostile to be plaintiff-favorable.