Experts say this could mean that more seniors will switch to Medicare Advantage plans

One reason that Part D premiums are increasing is utilization of popular GLP-1 medications like Novo Nordisk's Ozempic.

Medicare is scrapping a temporary program that helped keep the price of monthly premiums in check for older adults with Part D prescription drug plans.

That could mean that there is an increase next year in the cost of the premiums, though it's not yet clear what those increases may look like. Those premiums cost $36 a month on average this year, according to KFF.

The Centers for Medicare and Medicaid Services has said it started the program in 2025 to hold drug prices steady. However, a Trump administration official told the Wall Street Journal on Tuesday that the program incentivized health insurers, which received more than $3 billion this year, to raise rates. The official also said the subsidies weren't needed.

The cost of prescription medications is closely watched by senior citizens, who are typically on a fixed income and may find it difficult to adjust to a price increase. For about 25% of beneficiaries, premiums will be either flat or down, while 30% will have an increase of less than $10 to their monthly bill, and the remaining 45% will see increases of $11 to $20 a month, according to the official's comments to the Journal.

"What they are doing is shifting the premium cost more to the older retirees," Marcia Mantell, an independent retirement consultant and author of "Creating Your Medicare Recipe," told MarketWatch. "That's not great, but it's not nearly as bad as changing the costs of the drugs."

Medicare Part D is private prescription-drug coverage offered to people enrolled in traditional Medicare and is also included in most Medicare Advantage plans. Part D premiums are going up in part because of spending on pricey and popular medications like GLP-1s.

"With the termination of the extra subsidies that [prescription-drug plan] sponsors have received for the last two years, many PDPs may soon seem even less affordable than [Medicare Advantage prescription-drug plans] by comparison, exacerbating a shift of enrollment into Medicare Advantage plans," Juliette Cubanski, director of KFF's Medicare policy program, told MarketWatch.

Several experts believe the change will force seniors to switch to Medicare Advantage plans once they are faced with higher premiums or reduced offerings within their plans.

"This fall, Medicare beneficiaries would be well advised to shop around for their drug coverage, but they should not rely on comparisons of premiums alone," said David Lipschutz, co-director of the Center for Medicare Advocacy, in a statement.

-Jaimy Lee -Beth Pinsker