The Affordable Care Act Medicaid Expansion, Social Disadvantage, and the Practice Location Choices of New General Internists

Background: A recent study found that states that expanded Medicaid under the Affordable Care Act (ACA) gained new general internists who were establishing their first practices, whereas nonexpansion states lost them. Objective: The objective of this study was to examine the level of social disadvantage of the areas of expansion states that gained new physicians and the areas of nonexpansion states that lost them. Research Design: We used American Community Survey data to classify commuting zones as high, medium, or low social disadvantage. Using 2009–2019 data from the AMA Physician Masterfile and information on states’ Medicaid expansion status, we estimated conditional logit models to compare where new physicians located during the 6 years following the expansion to where they located during the 5 years preceding the expansion. Subjects: A total of 32,102 new general internists. Results: Compared with preexpansion patterns, new general internists were more likely to locate in expansion states after the expansion, a finding that held for high, medium, and low disadvantage areas. We estimated that, between 2014 and 2019, nonexpansion states lost 371 new general internists (95% confidence interval, 203–540) to expansion states. However, 62.5% of the physicians lost by nonexpansion states were lost from high disadvantage areas even though these areas only accounted for 17.9% of the population of nonexpansion states. Conclusions: States that opted not to expand Medicaid lost new general internists to expansion states. A highly disproportionate share of the physicians lost by nonexpansion states were lost from high disadvantage areas, potentially compromising access for all residents irrespective of insurance coverage.