Background: The purpose of this study was to assess the effect of individual state Medicaid expansion status on access to care for shoulder instability. Methods: Four pairs of Medicaid expanded (Louisiana, Kentucky, Iowa, and Nevada) and unexpanded (Alabama, Virginia, Wisconsin, and Utah) states in similar geographic locations were chosen for the study. Twelve practices from each state were randomly selected from the American Orthopedic Society for Sports Medicine directory, resulting in a sample size of 96 independent sports medicine offices. Each office was called twice to request an appointment for a fictitious 16-year-old first-time shoulder dislocator with either in-state Medicaid insurance or Blue Cross Blue Shield (BCBS) private insurance. Results: A total of 91 physician offices in 8 states were contacted by telephone. An appointment was obtained at 36 (39.6%) offices when calling with Medicaid and at 74 (81.3%) offices when calling with BCBS (P < .001). Thirty-five (38.5%) offices were able to make appointments for both types of insurance, 39 (42.9%) for only BCBS, 1 (1.1%) for only Medicaid, and 16 (17.5%) for neither. For Medicaid patients, an appointment was booked in 13 (27.7%) clinics from Medicaid expanded states and in 23 (52.3%) clinics from unexpanded states (P = .016). Conclusion: For a first-time shoulder dislocator, access to care is more difficult with Medicaid insurance compared with private insurance. Within Medicaid insurance, access to care is more difficult in Medicaid expanded states compared with unexpanded states. Medicaid patients in unexpanded states are twice as likely as those in expanded states to obtain an appointment.