An estimated 4 million adults aged 19-64 have lost health coverage since 2016, according to the Commonwealth Fund’s latest Affordable Care Act Tracking Survey. An estimated 15.5% of working-age adults were uninsured during the February-March survey, down from 12.7% in February-March 2016. Rates were higher among households earning less than 250% of the federal poverty level (25.7%) and in states that did not expand Medicaid (21.9%).