Kaiser Permanente benefited from stronger investment returns in the first quarter of 2021, but continues to shoulder higher expenses related to COVID-19.

Hospitals have up to 90 days to correct issues identified in the warning letter. If they don't follow through, CMS could penalize or publicly name and shame them.

While activists and humanitarian groups have cheered the Biden administration's decision and urged others to follow suit, European Union leaders have taken the U.S. to task for not sharing more vaccines with the rest of the world.

Strong performance in Cigna Corp.'s Evernorth health services division, investment portfolio and low member medical costs at the end of last year increased the company's revenue 6.5% year-over-year during the first quarter of 2021.