Going into President Barack Obama’s last year in office, progress has stalled on reducing the number of uninsured Americans under his signature health care law, according to a major survey out Thursday.

The share of U.S. adults without health insurance was 11.9% in the last three months of 2015, essentially unchanged from the start of the year, according to the Gallup-Healthways Well-Being Index. The ongoing survey, based on daily interviews with 500 people, has been used by media, social scientists, and administration officials to track the law’s impact.