Summary

The U.S. Department of Labor finalized a new rule on October 29, 2026. It requires pharmacy benefit managers, or PBMs, to disclose their rebate and fee arrangements. The disclosure goes to the employers who hire them. Specifically, it covers rebates negotiated with drugmakers. It also covers “spread” payments that PBMs keep when a plan pays more than a pharmacy is reimbursed. Consequently, employers will finally see the gap between the billed price and the price actually paid.

Access Impact

Hidden rebates hide the real price. Moreover, a hidden price breaks every model built on top of it.

PBMs sit between drugmakers, insurers, and patients. They negotiate rebates with manufacturers. In some contracts, they also keep part of the spread between what a plan pays and what a pharmacy is reimbursed. However, employers until now could not see these numbers. The new rule changes that. PBMs must disclose rebate and fee data at contract renewal. Furthermore, they must disclose it again every six months. Employers can also audit the data once a year. For MARA’s framework, this is first a Budget Impact issue. A budget model is only as accurate as the net price it uses. Specifically, once the real price moves from hidden to disclosed, every downstream calculation built on an assumed price needs a second look.

Budget Impact

Budget Impact scoring asks a simple question. What does this drug actually cost the system, after every rebate and fee is counted? Until this rule, that number depended on what a PBM chose to share. Now, under the new rule, self-funded employers get rebate and spread-pricing data on a fixed schedule. As a result, Budget Impact estimates that relied on list price as a stand-in for net price lose their main excuse. Regulators project the rule will lower drug costs by $22 billion over ten years. However, that figure assumes employers act on the data they now receive. Even so, the direction of the data flow has changed for good.

Cost-Effectiveness

Cost-effectiveness analysis depends on one key number: the true cost per outcome gained. If that number is the list price rather than the net price, the resulting ratio is wrong. This is true even when every other input is correct. This rule does not fix cost-effectiveness models directly. Instead, it removes one layer of the opacity that has made net price hard to pin down in the US market. As a result, analysts building a cost-effectiveness case for a US payer now have a real path to the true number, instead of a guess. Notably, that path still depends on employers actually requesting the data.

Evidence Quality

Evidence quality is not only about trial design. It is also about whether the inputs feeding an economic model are themselves verifiable. A rebate figure that a PBM will not disclose is not evidence. Instead, it is an assumption dressed up as a fact. The new disclosure rule turns some of these assumptions into checkable records. Even so, the rule applies only to self-funded employer plans. It does not cover the full market. Therefore, evidence quality improves unevenly, not everywhere at once.

Risk Signal

A number nobody can check is not a number.

For portfolio and investment teams, this rule is a reminder. A reported “net price” in a deal model is often an estimate, not a verified figure. This is especially true in the PBM-administered employer market. Moreover, an access case built on an unverified net price carries a risk that stays hidden until someone finally audits the contract. Therefore, before committing capital to a drug with a complex US rebate structure, the better question is not “what is the list price.” Instead, ask “who has actually seen the net price, and when.” If the answer is no one yet, what does that say about the diligence already done on the deal?

#MarketAccess #HTA #MARArating #PBM #DrugPricing #USHealthcare

Explore MARA’s market access framework: https://mararating.com/market-access-pharma/
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