Projecting Primary Care Use in the Medicaid Expansion Population: Evidence for Providers and Policy Makers

Millions of low-income adults are beginning to gain Medicaid coverage under the Affordable Care Act. To forecast the resulting need for primary care providers, we estimate the effect of Medicaid take-up on visits to office-based primary care providers, including clinics. We estimate that adults with Medicaid coverage at any point in the year have an average of 1.32 visits per year to primary care providers, 0.48 more visits than low-income adults without Medicaid. Consequently, we project a need for 2,113 additional primary care providers (range: 1,130-3,138) if all states expand Medicaid. Our estimates are somewhat lower than several recent forecasts, which may not have controlled adequately for selection bias, and which used non-representative samples for forecasting. Our findings shed light on disparities in access to care, particularly in counties with relatively few primary care providers per capita. Efforts to expand access to primary care should focus on where providers practice, rather than simply training more providers.