Previous Medicaid status of children newly enrolled in supplemental security income.

The Supplemental Security Income (SSI) program for children and adolescents has experienced a fourfold enrollment growth since 1989. Most SSI recipients also receive Medicaid, and SSI growth could therefore lead to major new Medicaid expenditures of new SSI recipients were not previous Medicaid enrollees. Using Medicaid claims for 1989-92, we determined whether SSI expansions included many children new to Medicaid as well as whether children with certain disabilities were more likely to have had Medicaid prior to SSI enrollment. Rates of new SSI enrollees without previous Medicaid coverage decreased from 53 percent in 1989 to 39 percent in 1992.