The Affordable Care Act required most people to obtain health insurance or pay a tax penalty. Legislation enacted in December 2017 effectively repealed that requirement, starting in 2019. This article reviews recent research on the mandate's effects, concluding that the mandate meaningfully increased insurance coverage, but likely by less than was projected before implementation. These coverage gains are likely to erode as mandate repeal takes hold. Looking ahead, policy makers have many options for expanding insurance coverage without restoring an individual mandate. However, achieving universal coverage without some form of mandatory individual contribution to health insurance would have a very large fiscal cost.