Far fewer Americans enrolled in an Affordable Care Act health care plan, new federal data shows, with millions facing higher premiums after tax subsidies under the insurance program expired in December According to figures  from the Centers for Medicare and Medicaid Services (CMS), 22.8 million people have signed up for ACA coverage for 2026 since open enrollment started on Nov. 1. That's down 1.4 million from the number of Americans who had enrolled in Obamacare, as the health plans are known,