The Medicaid Buy-In program, a state Medicaid option since the late 1990s, is designed to encourage adults with disabilities to work by allowing them to buy into Medicaid when their earnings exceed standard Medicaid eligibility limits. This article describes enrollment, expenditures, and earnings for Buy-In participants in 27 states between 2000 and 2004. Younger participants receiving no federal income support when they enroll in the Buy-In program have higher earnings, compared with older participants receiving Social Security Disability Insurance payments. The innovative process used in this study to link data from multiple agencies could be adapted for exploring other policy issues related to employment of individuals with disabilities.