The insurer’s stock sank to its lowest level in more than a decade after the federal government lowered the rating for one of its most popular plans.

Only 25% of Humana members will be in plans with four stars or above next year, down from 94% this year, the insurer disclosed Wednesday. The downgrade could wipe out Humana’s profits in 2026.

Humana’s stock was headed for another sharp selloff on Tuesday, toward a more than four-year low, after the government cut its rating on one of the health insurer’s large Medicare Advantage plans because it missed some performance measures.