Key Points Question Are there disparities in dentist availability for delivering dental care to children within or between states? Findings In this cross-sectional study of 204 279 active dentists across the US, dentist participation in public insurance programs varied substantially across states, especially for states that manage the Medicaid program and Children’s Health Insurance Program (CHIP) separately and within states. Dentist participation was lowest among dentists with urban practices and highest among those with rural practices, and notably lower among general dentists vs pediatric dentists. Meaning The findings of this study suggest that limited availability of pediatric dental care services remains a challenge in the US, especially for Medicaid- and CHIP-insured children, those living in rural communities, and those receiving specialized care.