The fourth brief in a series on the Medicaid Buy-In program, a key component of the federal effort to help people with disabilities return to work without losing health insurance coverage, examines earnings after enrollment. The brief notes that nearly 40 percent of participants increase their earnings after enrolling, with substantial differences in rate of earnings growth based on participant characteristics and across states. Sixty-five percent of participants under age 21 increased their earnings after enrollment, with a steady decline to 47, 33, and 30 percent for those ages 21 to 44, 45 to 64, and 65 and older, respectively. For those whose earnings rose, the median increase was $2,582.