UnitedHealth shares tumbled early Thursday after the company cut its 2025 forecast in the wake of a surprising rise in care use from its Medicare Advantage customers, leading to a worse-than-expected first quarter.

UnitedHealth Group surprised investors with what its CEO said was an "unusual and unacceptable" quarterly earnings miss, and it lowered its outlook for the full year due to higher-than-expected medical costs,

UnitedHealth Group (UNH) stock tumbled 19% Thursday after the company drastically cut its 2025 earnings forecast, citing significantly higher-than-expected medical costs tied to a surge in demand for outpatient and physician services within its Medicare Advantage plans.