The Supplemental Security Income (SSI) program, a federal income support program administered by the Social Security Administration (SSA), which includes children under age 18 with disabilities in low-income households, has grown in recent years. The growth in the child SSI caseload has varied substantially by state (as has the adult SSI caseload), though the factors driving this growth are not well understood (U.S. Government Accountability Office 2012; Aizer et al. 2013).

This brief examines state and county variation in child SSI caseloads for the most recent year in which data are available (2013), and state variation in child SSI caseload growth in the past 15 years (1998 to 2013). During this 15-year period, there were no major changes in child SSI eligibility requirements, yet child SSI caseloads grew by 45 percent nationally. The brief presents maps to observe trends and regional patterns in caseload growth, relative to the number of children and the number of children in low-income households. The maps provide insights into the regional patterns in child SSI participation and potential sources of caseload growth, and suggest clustering of program participation that varies substantially across and within states, and that often spans state lines. While this analysis cannot determine the specific factors driving the SSI caseload growth in recent years, it does indicate that regional, state and local factors appear to play an important role in the geographic variation in program growth.