Which physicians limit their Medicaid participation, and why

This study identifies factors differentiating Medicaid participating physicians who accept all Medicaid patients from those limiting their Medicaid participation.

Data come from periodic telephone surveys of random samples of physicians conducted by the American Medical Association (AMA).

Surveys conducted in 1990-1993 were pooled to form a sample of 4,188 Medicaid-participating office-based physicians. Respondents were classified as accepting all Medicaid patients or as limiting their Medicaid participation. Descriptive statistics are used to examine differences between these groups with respect to selected personal, practice, community, and reimbursement variables. Logistic regression analysis is used to identify factors associated with physicians accepting all Medicaid patients or limiting their Medicaid participation in some way.

Survey data were supplemented with 1990 census data, 1990 AMA Physician Masterfile data, and 1989 data on physician payment levels.

Less than half of Medicaid-participating physicians and only about one-third of participating primary care physicians accept all Medicaid patients. Higher Medicaid fees are associated with physicians participating fully, but the marginal effects of changes in fees on the probability of physicians participating fully is small.

Increases in Medicaid reimbursement aimed at primary care physicians or those in underserved areas may convert limited participants into full participants and, in so doing, improve the access of Medicaid eligibles to care. The increases in payment level needed to increase the proportion of physicians participating fully would be substantial, however, and may not be politically feasible.