Millions of Americans can get Medicare to cover GLP-1s for weight loss starting this week. Here’s how much it costs.

Medicare officially began covering GLP-1 drugs for weight loss and obesity treatment this week, a significant policy shift from coverage that was previously limited to Type 2 diabetes, sleep apnea, and cardiovascular risk reduction. The change potentially unlocks access for tens of millions of Medicare beneficiaries who are obese but do not carry those specific diagnoses, representing a substantial new addressable market for the leading GLP-1 drugmakers.

The primary beneficiaries of this expansion are Novo Nordisk (NVO), maker of Ozempic and Wegovy, and Eli Lilly (LLY), maker of Mounjaro and Zepbound — the two dominant players in the GLP-1 space. Both companies have been racing to expand manufacturing capacity, and this policy shift could meaningfully accelerate volume growth in the U.S. market at a time when both are already managing global demand backlogs.

The bull case centers on a sudden, government-mandated demand unlock: Medicare is one of the largest payers in the country, and coverage expansion typically translates into a durable, recurring revenue stream rather than a one-time pop. However, the bear case is real — Medicare coverage comes with negotiated pricing pressure, meaning net revenue per unit could compress significantly compared to commercial insurance rates, possibly offsetting volume gains.

On the flip side, companies like Intuitive Surgical (ISRG) and bariatric-focused providers could see long-term headwinds as GLP-1 drugs increasingly substitute for surgical weight-loss interventions. Pharmacy benefit managers and insurers managing Medicare Part D formularies will also be central players in how quickly and how broadly uptake occurs.

The key variables to watch: how aggressively CMS negotiates pricing for these drugs under Part D, whether manufacturing bottlenecks at NVO and LLY constrain the actual volume benefit, and how quickly physicians begin prescribing under the expanded indication. Earnings calls from both NVO and LLY will likely be the first venue where quantified guidance on Medicare volume appears.