The Patient Protection and Affordable Care Act (ACA, P.L. 111-118, as amended) required all states to provide Medicaid coverage to children with family incomes up to 138 percent of the federal poverty level (FPL) beginning in January 2014. States that had been covering stairstep children—that is, children whose family income was too high to qualify for Medicaid yet below 138 percent FPL— in separate CHIP were required to transition them to Medicaid. This presentation summarizes findings from a recently completed MACPAC study of how states implemented the transition, including strategies for facilitating the transition and challenges.