How Do Providers Respond to Public Health Insurance Expansions? Evidence from Medicaid Adult Dental Benefits

A large and growing number of non-elderly adults are covered by public insurance, and the Affordable Care Act is scheduled to dramatically increase public insurance coverage in the next several years. This study evaluates how such large increases in public coverage affect provider behavior and patient wait times by analyzing a common and important type of primary care: dental services.

We find that when states add dental benefits to adult Medicaid coverage, dentists' participation in Medicaid increases and dentists see more publicly insured patients without decreasing the number of visits provided to privately insured patients. Dentists increase the total number of visits they supply each week without a large increase in hours worked per week, primarily by making greater use of dental hygienists. When states add dental benefits to Medicaid, dentists employ more hygienists and hygienists provide a greater number of visits per week. These changes in provider behavior are most pronounced among dentists who practice in poor areas where Medicaid coverage is largest.

Wait times for appointments increase modestly when states add dental benefits to the Medicaid program. However, there is significant heterogeneity in the effect on wait time: the largest increases in wait times are observed in states with restrictive scope of practice laws governing dental hygienists.