Patients file a class action over CVS Caremark's decision to drop Zepbound

A group of patients has filed a class-action lawsuit against CVS Caremark, arguing the pharmacy benefit manager unlawfully changed its coverage rules for Zepbound, the tirzepatide drug made by Eli Lilly ^[1]. The suit, filed September 3 in the U.S. District Court for the Southern District of New York, says Caremark's decision to remove Zepbound from its main formularies breached its fiduciary duty under the Employee Retirement Income Security Act, or ERISA ^[1].

Earlier this year, Caremark said it would drop Zepbound from its standard control, advanced control, and value formularies effective July 1, and give preferred status instead to Wegovy, Novo Nordisk's semaglutide drug for weight loss ^[1]. Caremark said the two drugs are interchangeable and that giving Wegovy preferred placement would use competition to lower costs ^[1].

The plaintiffs disagree. They argue Zepbound and Wegovy are different molecules, tirzepatide and semaglutide, with different mechanisms, different side-effect profiles, and different FDA approvals ^[1]. Zepbound is the only one of the two approved for patients with obesity and obstructive sleep apnea, and the lawsuit points to one plaintiff who was diagnosed with sleep apnea and says the drug was medically necessary for that condition ^[1]. The complaint also says some patients who had severe symptoms on semaglutide had a milder experience on tirzepatide, and it cites Caremark's own formulary page, which acknowledges studies suggesting Zepbound is more effective for weight loss while stating that "real-world evidence suggests the two are comparable" ^[1].

The plaintiffs say their claims for Zepbound coverage were "improperly denied" and that the denials were "arbitrary and capricious," ignoring plan language, medical necessity, and their own doctors' recommendations ^[1]. A Caremark spokesperson called the lawsuit "without merit" and said the company intends to defend against it, adding that Caremark has an exemption process available for members who need it ^[1]. The spokesperson said the formulary strategy "maintains clinically appropriate coverage while using competition to drive lower costs" and is meant to produce "lower costs and better outcomes for consumers and our customers" ^[1].

Why it matters for patients

For people who were already taking Zepbound and had it working for them, formulary changes like this one can mean a sudden switch to a different drug, an appeal process, or paying out of pocket, even if a doctor considers the original drug medically necessary ^[1]. The lawsuit highlights a tension in how health plans handle the GLP-1 class: PBMs argue that drugs within the class are similar enough to swap for cost reasons, while patients and some doctors say individual response to tirzepatide versus semaglutide can differ significantly ^[1].

The case also turns on a legal question that could matter beyond this one drug: whether a PBM's formulary decisions, when they override a treating doctor's judgment, can amount to a breach of fiduciary duty under ERISA, the federal law that governs most employer-sponsored health plans ^[1]. Caremark says it has an exemption process for members who need continued access, but the lawsuit argues that process did not work as intended for these plaintiffs ^[1].

What happens next

The case was filed September 3 in New York's Southern District Court, and Caremark has said it will fight the claims ^[1]. This source does not detail a timeline for how the litigation will proceed or address whether CVS Caremark plans to change its Zepbound coverage decision for 2026 plan years; that detail is not addressed in the available reporting. Patients affected by formulary changes may want to watch for updates from CVS Caremark and Eli Lilly, as well as any court rulings on the fiduciary-duty claims, since a decision could affect how PBMs handle similar drug-class substitutions in the future.