Summary: This report evaluates the effectiveness of the 40 hours per month work requirement for eligibility for CommonHealth Working, Massachusetts\u27 Medicaid Buy-In program. The evaluation compared CommonHealth Working to other Massachusetts Medicaid programs and to other state Buy-In programs, examining enrollee earnings, hours worked, expenditures and enrollment patterns. The study also analyzed the impact of eligibility rules and case closure data on enrollment. Prepared for the Commonwealth of Massachusetts Executive Office of Health and Human Services