The health care giant's shares are down more than 50% in the last month. That's hurting the powerful U.S. stock-market index.

The health care conglomerate is facing mounting financial problems – and ongoing consumer anger over high costs and denied claims.

Luigi Mangione, who is accused of killing UnitedHealthcare CEO Brian Thompson, had his first court appearance since he was arraigned in December on charges including murder as an act of terrorism.

Patients are protesting, bipartisan lawmakers are threatening regulation – and investors are selling their shares. 

The man accused of killing UnitedHealthcare's CEO has been charged with murder as an act of terrorism. The indictment could help move along procedural steps toward extraditing the suspect.

The man charged in the killing of UnitedHealthcare CEO Brian Thompson was critical of U.S. health care. Experts say the system's problems are complex and can't be pinned on one player or industry.

Police say the suspect had a ghost gun, possibly made with a 3D printer, when he was arrested on Monday. Here's what to know about the increasingly widespread weapons and efforts to regulate them.

Luigi Mangione, the man facing charges in the New York City shooting death of UnitedHealthcare CEO Brian Thompson, was denied bail in Pennsylvania on Tuesday.

Manhattan prosecutors Monday night filed murder and other charges against Luigi Mangione, 26, in the killing of UnitedHealthcare's CEO last week, according to online court documents.

Manhattan prosecutors filed murder and other charges against Luigi Mangione Monday night. Earlier in the day Mangione was arraigned on firearms and forgery charges in Pennsylvania after his arrest.

The death of UnitedHealthcare CEO Brian Thompson triggered a deluge of painful stories about health care denials on social media.

The manhunt for the person who fatally shot the head of one of the country's largest health insurers in New York City entered its third day Friday as police parsed newly discovered clues.

Shell casings with the cryptic words "deny," "defend" and "depose" were found at the scene of the fatal shooting of the UnitedHealthcare CEO outside of a Manhattan hotel, police officials say.

Agreeing to an out-of-network doctor's financial policy, which protects their ability to get paid and may be littered with confusing jargon, can create a binding contract that leaves a patient owing.