Under President Trump, how, exactly, is the Affordable Care Act (ACA) likely to change, and how will this fundamental policy shift affect the U.S. health care and health insurance systems? The short answer, as the new administration was taking shape: Nobody knows. But whether it’s a “repeal and replace,” as many congressional Republicans have advocated ever since the law was enacted in 2010, or “repeal and delay” or “partial repeal” or “repair” (as some are now suggesting) or just “repeal,” it seems certain that change is on the way. This article summarizes discussion of these issues by a panel of experts at EBRI’s 79th policy forum held in Washington last December, and attended by more than a hundred people. Press release.