Medicaid Buy-In participants who receive Social Security Disability Insurance (SSDI) benefits may not be taking full advantage of the available work incentive programs that can improve their prospects of finding employment and attaining economic self-sufficiency. This policy brief, the seventh in a series on working with disability, reveals that only 23 percent of Medicaid Buy-In participants who received SSDI benefits between 2000 and 2005 took part in a work incentive program. The brief summarizes Mathematica's study of participation rates for four SSDI work incentive programs: Trial Work Period, Extended Period of Eligibility, Impairment-Related Work Expenses, and Ticket to Work. The Trial Work Period program was the most utilized,with approximately 16 percent of beneficiaries participating. The Extended Period of Eligibility program had the second highest participation rate, 7 percent, with Ticket to Work running a close third with 6 percent. Fewer than one percent utilized the Impairment-Related Work Expenses incentive.