The Department of Labor’s Employee Benefits Security Administration finalized a rule on October 29, 2026 requiring pharmacy benefit managers to disclose manufacturer rebates, spread pricing, and pharmacy recoupments to self-funded plan sponsors. The final rule takes effect 60 days after Federal Register publication, with the substantive disclosure duties attaching to plan years beginning on or after July 1, 2027. It follows the proposed version DOL published in January, covered here in April, and layers onto the separate rebate pass-through mandate under the Consolidated Appropriations Act of 2026.
Who it affects
Self-insured employers, Taft-Hartley funds, and public-entity health plans that route pharmacy benefits through a PBM, which is nearly all of them. The disclosure duty runs to the plan fiduciary, so the people on the hook to act on the new data are the same risk managers and CFOs who sign off on the IBNR number, not just the PBM contract negotiator.
The reserve mechanism this changes
Here’s the argument worth sitting with: the risk isn’t that the rule lowers pharmacy costs, it’s that it exposes how wrong the current baseline already is. Most self-funded plans carry a net-of-rebate Rx trend assumption in their expected claim ratio (ECR) that is sourced from the PBM’s own reporting, because until now there was no independent way to check it. The rule requires PBMs to disclose expected compensation before each contract or renewal, then actual compensation every six months, and gives sponsors an annual audit right starting with plan years on or after July 1, 2027, with the sponsor free to pick the auditor. Having tracked the gap between PBM-reported “net cost” and what shows up in actual plan financials across a dozen renewal cycles, the pattern holds: sponsors who never audit simply book whatever rebate figure the PBM hands them. The first audit under this rule is likely to show that figure overstated, which means the gross-to-net adjustment baked into current reserve models understates the real pharmacy cost base. Where that gap surfaces, the fix isn’t a gradual trend revision; it’s a restated baseline for the affected plan years, since reserves already set using the old assumption were wrong from the start rather than drifting.
What this means for your next review
Ask your actuary three things: what net-of-rebate Rx trend is embedded in current IBNR, and is it sourced from PBM data or an independent benchmark; how a five-point swing in realized rebate retention would move the ECR for the current plan year; and whether to budget for a first-year PBM audit now so results can feed a reserve restatement rather than surface as a surprise at the next annual review. See the IBNR for self-funded health plans guide for how the gross-to-net adjustment fits into the broader pharmacy reserve build.