Objective: The present study examines the connection between the timing and size of Supplemental Nutrition Assistance Program (SNAP) benefits and the occurrence of emergency room (ER) visits for hypoglycaemia, a condition that is highly sensitive to short-term changes in nutritional intake. Design: We used administrative data from Missouri SNAP and Medicaid to identify the timing of issuance and the benefit size of SNAP and the timing of ER claims for hypoglycaemia. We estimated the probability of submitting an ER claim for hypoglycaemia as a function of the calendar week, SNAP benefit week and the size of the SNAP benefit in models that controlled for individual demographic characteristics. Setting: Missouri SNAP caseloadfrom January 2010 to December 2013 linked to adult Medicaid claims data for the same time period. Subjects: ER claims submitted to Medicaid (n 6 508 061). Results: The results indicated no evidence of a SNAP benefit cycle or monthly cycle to ER claims for hypoglycaemia. However, the analysis did find that ER claims for hypoglycaemia are related to the size of the SNAP benefit. Conclusions: These results suggest that more generous SNAP benefits help households avoid nutritional fluctuations in the quality and quantity of food that might result in low blood sugar, thus necessitating fewer ER visits for hypoglycaemia.