Geographic patterns of county prevalence rates of disability benefit receipt are shown for the Social Security Administration's Disability Insurance (DI) and Supplemental Security Income (SSI) programs. Prevalence rates were calculated by dividing each county's December 1990 DI and SSI disability caseloads by the population aged 18-64 for that year in that county. Separate maps were also constructed for men and women recipients. Areas with the highest overall DI prevalence rates included Appalachia, the Southeast Coastal Plains, the Mid-south, northwestern Montana, the coastal counties of Washington, and isolated counties of the Southwest. Areas with the highest SSI prevalence rates included the Mississippi Delta, scattered counties in Oklahoma, the Missouri "Boot Heel," parts of Appalachia, isolated counties in South and North Dakota, the "Four Corners" regions of the Southwest, the Sacramento and San Joaquin Valley regions of California, isolated parts of the upper Great Lakes States, northern Maine, and the coastal region of southwestern Alaska. Disability prevalence rates were also calculated for the overall population and by sex for each of the 10 U.S. Department of Health and Human Services administrative regions.