Related: Balancing the costs of GLP-1 weight loss drug coverage: New CBO report has some answers

CMS, an arm of the U.S. Department of Health and Human Services, would also add anti-obesity medications to the definition of drugs that should be part of states' Medicaid health program "formularies," or lists of covered drugs.

Medicare drug plans would have the same kind of discretion over which anti-obesity medications they cover that they have over drugs used to treat conditions other than obesity, but prior authorization rules for anti-obesity medications that are "overly restrictive may be deemed to be inconsistent with CMS' formulary review requirements if the criteria appear to be likely to substantially discourage enrollment of individuals with obesity in the Part D plan," CMS officials say.

Medicaid plans would have to cover at least some anti-obesity medications.

Proposal mechanics: CMS included an announcement about the anti-obesity medication coverage proposal in a packet of requirements proposed for the Medicare Part D drug plans and other commercial insurance plans, such as Medicare Advantage plans, that will be offered to Medicare plan enrollees signing up for 2026 coverage.

The regular annual enrollment period for 2026 private Medicare plans is set to begin Oct. 15, 2025.

The proposed regulations are on track to appear in the Federal Register, an official government regulatory publication, Dec. 10. Comments will be due Jan. 27, 2025.

What this means for benefit plans: CMS helps oversee federal rules and programs that affect commercial health insurance, but the new proposed requirements would not apply directly to employer plans.

But CMS officials acknowledge uncertainty about how the example they are setting could affect commercial health coverage providers indirectly.

The proposal "could prompt changes in private health plan coverage outside of Medicare and Medicaid," officials say in the preamble, or official introduction, to the proposed regulations. "This could impact premiums for those plans, including Affordable Care Act marketplace plans, but these impacts are not quantifiable without data on changes for the private health insurance market in response to this proposal. We request comment on the potential impact of our proposal on the private employer insurance market and the ACA marketplace."

In the past, some benefits experts have emphasized the enormous cost of covering GLP-1 agonists for even a small percentage of obese plan participants, but others have argued that employers will have to find ways to cover the drugs.

Health program basics: Medicare is a federal program that covers health services for about 64 million Americans who are aged 65 or older, have disabilities or face severe kidney disease.

Medicaid is a program run by both the federal government and states that provide care for low-income people and some other people who need nursing home care.

The cost: CMS officials predict that their proposal could lead to about $24.8 billion in extra Medicare spending over 10 years.

"While we expect that there could be offsetting medical savings due to treatment of obesity, those savings will be much slower to emerge, such that in the near-term, the costs will have a larger impact on the overall picture of the estimated financial impact of this proposal," officials write.

The future: The new anti-obesity medication coverage proposal was developed by officials working in the administration of President Joe Biden. Officials in the administration of President-elect Donald Trump could withdraw the proposed regulations, change them or replace them.

Robert F. Kennedy Jr., Trump's pick to lead HHS, appears to be skeptical about use of anti-obesity medications, but Dr. Mehmet Oz, a cardiothoracic surgeon and Trump's pick to be the next CMS administrator, has expressed enthusiasm about reports on the effects of one of the popular new GLP-1 agonists, Wegovy.

"I've been to a lot of American Heart Association meetings," Oz posted on the X social media service Nov. 13, 2023. "There is rarely a standing-room crowd! But that happened in Philly this weekend when the AHA discussed a new study that showed for the first time that the diabetes and weight loss drug Wegovy also reduced the chance of major heart problems by a whopping 20%! This is great news — now the question is how we, as a nation, can make these medications more affordable."