Shares of Humana tumbled early Wednesday after the health insurer said a Medicare Advantage quality rating drop will hurt future bonus payments the company receives.

The insurer said the number of customers currently enrolled in plans rated four stars or higher for 2025 is down 94% from this year. Humana said the rating on a large, national insurance plan that contains 45% of Humana's enrollment fell a point to 3.5 points.

Medicare Advantage plans are privately run versions of the federal government's Medicare program mostly for people age 65 and older. An annual enrollment window for 2025 coverage starts Oct. 15. Shoppers will have until December 7 to settle on coverage for next year.

Humana Inc. said in a regulatory filing that it was talking to federal officials about the reduction. The company said it also is focused on improving its performance to regain its star rating.

Humana, one of the biggest providers of Medicare Advantage coverage, said the ratings drop will not affect its results or outlook for this year and next. The company said it would explore all options to mitigate the revenue hit it expects to take in 2026 from a drop in bonus payments due to the rating change.

The Louisville, Kentucky, company's stock shed nearly $60 in value before markets opened Wednesday. The price dropped 21% to $219.88.

Shares had already fallen about 39% so far this year.