UnitedHealth Group, one of the largest and most diversified health insurance companies in the United States, said on Monday that it planned to buy Surgical Care Affiliates, a chain of outpatient surgery centers, for about $2.3 billion. The deal is expected to close in the first half of 2017.

Six years ago, federal health officials were confident they could save taxpayers hundreds of millions of dollars annually by auditing private Medicare Advantage insurance plans that allegedly overcharged the government for medical services.

The Obama administration on Tuesday starkly warned Republicans against a "repeal-and-delay" strategy on Obamacare as it announced that more than 11.5 million Americans have signed up for health insurance coverage on government-run marketplaces this enrollment season — a slight increase from last year.

Giving Medicare authority to negotiate drug prices is the best way to keep those spiraling costs under control for the program’s recipients, departing Health and Human Services Secretary Sylvia Burwell said Monday.

Republicans eager to scrap the 2010 health-care law are wrestling with whether to immediately cut off the tax revenue it brings in.

The Republican strategy of repealing the Affordable Health Care Act before devising a replacement plan has the support of only one in five Americans, a poll released Friday finds.