OBJECTIVE: To examine the association between insulin rationing and health care utilization. RESEARCH DESIGN AND METHODS: Cross-sectional study of all 2021 National Health Interview Survey respondents with diabetes using insulin. Logistic regression and zero-inflated negative binomial regression models examined associations between insulin rationing (skipping, delaying, or reducing insulin to save money) and 1) emergency department (ED) visit or hospitalization and 2) number of urgent care visits. All analyses were age-stratified and used survey weights. RESULTS: Among 982 respondents representing 7,593,944 U.S. adults (median age 61 years, 47% women), 17% reported rationing. Among adults 18-64 years old, rationing was not significantly associated with health care utilization. Among adults ≥65 years old, rationing was associated with more urgent care visits (relative risk 2.1, 95% CI 1.2-3.6) but not with odds of ED visit or hospitalization (odds ratio 0.7, 95% CI 0.3-1.4). CONCLUSIONS: Insulin rationing was not associated with higher health care utilization, but concurrent rationing of health care may mask a relationship.