By 2016, the Affordable Care Act is expected increase enrollment in the Medicaid program by over 12 million people. Whether this coverage expansion translates to improved access to care will depend on the willingness of providers to accept Medicaid and their ability to expand capacity to meet the increased demand. This panel consists of three papers that examine the provider responses to Medicaid coverage and reimbursement policies, with an emphasis on how these responses depend on scope of practice regulations. The ACA’s Medicaid expansion will mainly affect childless adults. The first paper, by Buchmueller, Miller and Vujicic, studies previous coverage expansions affecting this population. Specifically, the paper estimates the effect of changes in Medicaid coverage of adult dental services on several supply-side outcomes: whether or not a dental practice accepts Medicaid, the number of patients seen in a typical week, dentists’ labor supply and income, the employment of dental hygienists and patient wait times. The results indicate that an important way that practices respond to increases in demand caused by coverage expansions is to make greater use of dental hygienists. In states where hygienists enjoy greater autonomy, when coverage expands practices are able to treat more patients with no increase in wait times. In contrast, in states with more restrictive scope of practice laws, there is a smaller increase in supply and an increase in average wait times. The second paper, by Polsky and Richards, uses an experimental audit study design to examine how scope of practice laws affect the supply of care provided by primary medical care practices to publicly insured, privately insured and uninsured patients. The study was conducted in ten states with varying scope of practice regulations. In all regulatory environments, practices commonly employ non-physician providers. In states with more liberal scope of practice laws, the use of mid-level providers is associated with better access for Medicaid patients and lower prices per visit. In contrast, the authors find that a more diverse provider mix is not associated with provider willingness to accept a new Medicaid patient or the costs of services in states with more restrictive scope of practice rules. Reimbursement rates are another important policy lever affecting access for publicly insured patients. The third paper, by Chen, examines the effect of Medicaid payments to physicians on the supply of care to Medicaid patients and the uninsured. The analysis is based on data on physicians from the Community Tracking Survey combined with state-level data on Medicaid fees. The results indicate that increased Medicaid payments lead to an increase in supply of services to Medicaid patients and a decrease in supply of care to the uninsured. The results also suggest an important interaction between Medicaid eligibility and payment policies: the supply response to Medicaid payments is stronger when the fraction of the population that is eligible for Medicaid is higher.