Fiduciary Compliance Update, October 2026: An En Banc Argument, a Parity Roadmap, and a Deadline
September was a thin month for new law and a consequential one for pending law. The rule most self-funded sponsors were waiting on did not arrive. What did move was an argument in the year's largest third-party-administrator case, a piece of guidance that narrows what a mental health parity investigation will actually look at, and a registration deadline that quietly landed on your 2027 calendar.
This is the monthly digest of The Fiduciary Briefing. Every case, rule, and statute referenced below is tracked in full, with sources, in the Litigation and Regulatory Tracker.
1. The Fifth Circuit heard Aramark v. Aetna en banc
No. 24-40323, Fifth Circuit, sitting en banc. Argued September 24, 2026. Under advisement.
The full Fifth Circuit heard argument in New Orleans on September 24. The Department of Labor filed in support of Aramark.
It is worth being precise about what this case is, because it has been widely described as something it is not. The question is whether the make-whole monetary relief Aramark seeks counts as appropriate equitable relief under ERISA Section 502(a)(3). That determination controls whether the dispute has to go to arbitration under the parties' master services agreement. It is not a test of whether an administrator's discretion over claims makes it a functional fiduciary. A three-judge panel ruled against Aetna's bid to compel arbitration in December 2025; the en banc court vacated that opinion when it granted rehearing in April.
Aramark alleges that Aetna, as third-party administrator for its self-funded plans since 2018, paid over $200 million in improper claims, retained undisclosed fees, and commingled plan assets. Those allegations are unproven, and the court has not ruled on them.
What to do: if your ASO or TPA agreement contains an arbitration clause, have counsel read it against the equitable-relief question this court is deciding. A decision can now land in any given week, and the useful time to have that reading in hand is before the opinion, not after it.
2. EBSA told you where a parity investigation will go
EBSA Field Assistance Bulletin No. 2026-03. Issued September 8, 2026.
The Labor Department narrowed its enforcement of the mental health parity nonquantitative treatment limitation requirements to three priority areas: separate treatment exclusions that apply to mental health and substance use benefits but not to medical and surgical benefits; medical necessity review, including prior authorization and concurrent and retrospective review, applied inconsistently across those two classifications; and network adequacy, focused on provider admission standards and reimbursement methodologies that restrict in-network access. The Department said its prior approach had created substantial confusion and unnecessary burdens.
The bulletin also reconfirms that the new provisions of the 2024 parity rule will not be enforced until the pending ERISA Industry Committee litigation concludes, plus 18 months. Note the shape of that: it is tied to a case outcome, not to a date.
What to do: point your next comparative analysis at those three domains rather than at the whole 2024-rule inventory, and get the network-adequacy documentation from your TPA in writing, since that is the one of the three a plan sponsor cannot produce from its own records. The statutory parity duty and the CAA 2021 comparative-analysis requirement are unaffected by any of this.
3. A January 2027 deadline you can act on today
CMS Federal IDR Gateway. Registration opened September 15, 2026.
CMS opened account creation for the Federal IDR Gateway, the centralized platform replacing the current single-use web forms for No Surprises Act payment disputes. Initial functionality arrives in November 2026. The legacy web forms stop working on January 15, 2027. The Departments also certified a seventeenth independent dispute resolution entity on September 11.
What to do: if your plan administers disputes directly, create the account and complete identity verification well ahead of January 15. If a TPA handles it, get written confirmation of who is registering and that your plan's disputes are mapped to that registration. A missed registration is an operational failure, and the cost of one is losing the ability to respond to a dispute on time.
Also worth knowing
The PBM fee-disclosure rule did not arrive. The Labor Department's pharmacy benefit manager fee disclosure rule has been at the White House regulatory review office since July 23 and did not publish in September, past its own stated September target. It carries no statutory deadline, so the timing can keep slipping. Treat the fourth quarter as the planning horizon rather than assuming the target held.
Two courts, five days apart, disagreed about state PBM reporting. The Seventh Circuit held on August 26 that ERISA does not preempt an Arkansas PBM rule, treating the state's dispensing-fee authority as ordinary cost regulation and the reporting requirement as incidental to enforcing it. Five days later an Illinois federal court preliminarily enjoined that state's PBM reporting mandates as likely preempted, reading them as exactly the kind of standalone data-collection regime ERISA forbids. Whether a state PBM rule reaches your plan is becoming a question of which circuit you are in.
Nothing new was filed. No new ERISA health-plan fiduciary case filed in September could be verified against a real docket. That is a checked result rather than an absence of checking. The action is on the existing docket: the Wells Fargo appeal is now fully briefed at the Eighth Circuit with substantial employer-side amicus participation, and a plaintiffs' reply brief is due October 7.
Take the next step
If you want to know where your own plan sits against the standards above, a CLEAR™ review maps your ASO, PBM, and Stop-Loss contracts to the eight fiduciary duties and the current case standards, and returns a written summary you can share with counsel. Get a complimentary ASO review.
Related resources
FAQs
What is the Aramark v. Aetna case actually about?
It asks whether the make-whole monetary relief Aramark seeks counts as appropriate equitable relief under ERISA Section 502(a)(3). That answer decides whether the dispute must go to arbitration. It is not a test of whether a third-party administrator is a functional fiduciary.
Has the Fifth Circuit decided Aramark v. Aetna?
No. The full court heard argument on September 24, 2026, and the case is under advisement. The court could issue a decision at any time.
What did EBSA Field Assistance Bulletin 2026-03 change for mental health parity?
It did not change the law. It narrowed EBSA's enforcement focus to three areas: separate treatment exclusions, medical necessity review, and network adequacy.
When do the legacy No Surprises Act dispute web forms stop working?
On January 15, 2027. CMS opened Federal IDR Gateway registration on September 15, 2026, and initial functionality arrives in November 2026.
Is the Labor Department's PBM fee-disclosure rule final?
No. The final rule has been under White House regulatory review since July 23, 2026, and it had not been published as of September 30, 2026.
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