Massachusetts Inpatient Medicaid Cost Response to Increased Supplemental Nutrition Assistance Program Benefits

OBJECTIVES: To investigate the impact of an increase in Supplemental Nutrition Assistance Program (SNAP) benefits on Medicaid costs and use in Massachusetts. METHODS: Using single and multigroup interrupted time series models, I examined the effect of an April 2009 increase in SNAP benefits on inpatient Medicaid cost and use patterns. I analyzed monthly Medicaid discharge data from 2006 to 2012 collected by the Massachusetts Center for Health Information and Analysis. RESULTS: Inpatient costs for the overall Massachusetts Medicaid population grew by 0.55 percentage points per month (P < .001) before the SNAP increase. After the increase, cost growth fell by 73% to 0.15 percentage points per month (-0.40; P = .003). Compared with the overall Medicaid population, cost growth for people with the selected chronic illnesses was significantly greater before the SNAP increase, as was the decline in growth afterward. Reduced hospital admissions after the SNAP increase drove the cost declines. CONCLUSIONS: Medicaid cost growth fell in Massachusetts after SNAP benefits increased, especially for people with chronic illnesses with high sensitivity to food insecurity.