UnitedHealth Group cut its annual profit forecast on Thursday in anticipation of higher costs for the insurer from a bigger-than-expected jump in medical care among older adults, sending its shares crashing 17% in premarket trading.

The forecast cut also dragged down shares of other health insurers and pushed the U.S. Dow Index futures into negative territory. Elevance, CVS Health, Cigna, Centene and Humana all fell between 4% and 9%.

“UnitedHealth Group grew to serve more people more comprehensively but did not perform up to our expectations, and we are aggressively addressing those challenges to position us well for the years ahead,” CEO Andrew Witty said.

The health insurance industry has been grappling with increased costs since mid-2023 due to a surge in demand for healthcare services under government-backed Medicare plans for older adults or individuals with disabilities.

Costs related to the company’s Medicare Advantage business were far above the planned 2025 increase and were consistent with the elevated levels in 2024, the company said.

The company now expects 2025 adjusted profit per share to be between $26 and $26.50 per share, compared with its prior forecast of $29.50 to $30 per share. Analysts were expecting a profit of $29.73 per share for 2025, according to data compiled by LSEG.