In this third of a series of ten briefs on states' implementation of the Affordable Care Act, Urban Institute researchers summarize their findings from a site visit and extensive interviews with Maryland state officials and health care stakeholders. The analysis of the state's progress to date highlights successes and challenges related to insurance exchange planning and information technology development, private insurance market reforms, Medicaid, and provider and insurance markets. Gubernatorial leadership, stakeholder involvement, legislative progress, the state's prior experience in health system reform, and the importance of the states all-payer hospital rate-setting system are all discussed.