Research Objective: Interventions for type 2 diabetes (T2D) often focus on lifestyle, including diet and physical activity. The Look AHEAD (Action for Health in Diabetes) study is one of the largest randomized trials of an intensive lifestyle intervention (ILI). Starting in 2001, 5145 adults with overweight/obesity and T2D were randomized to ILI or conventional diabetes support and education. The ILI led to persistent reductions in weight (8.6% in first year), improved diabetes control, and reduced self-reported hospitalizations and prescription drug use during the 12-year intervention. However, it is unclear whether benefits persisted beyond the intervention. We linked Look AHEAD participants to Medicare data to estimate the long-term effects of ILI on health care use. Study Design: We estimated differences in healthcare use between ILI and control groups during 2012-2015 (immediately after the intervention), adjusting for baseline characteristics. We focused on measures of healthcare use that were available for traditional Medicare and private Medicare Advantage enrollees, including hospitalizations, emergency visits, and prescription drug use. We also estimated whether the ILI affected disability-related Medicare eligibility. Population Studied: We linked 2,796 participants to Medicare data out of 3,246 consenting to linkages after the Look AHEAD intervention phase. Principal Findings: We found significantly lower annual Part D drug costs for the ILI group between 2012-2015 (-$401, p=0.029). Annual emergency department visits and hospitalizations were not significantly different between intervention groups in 2012-2015. A similar percentage of ILI and control group participants were initially eligible for Medicare before age 65 due to disability. Conclusions: The ILI led to reductions in prescription drug use and costs that persisted beyond the intervention, but did not affect long-term hospitalizations, emergency visits, or eligibility for Medicare through disability. Disclosure P.J. Huckfeldt: Employee; Spouse/Partner; U.S. Department of Veterans Affairs. C. Frenier: None. N.M. Pajewski: None. M. Espeland: Research Support; Self; National Institutes of Health. Other Relationship; Self; Boehringer Ingelheim International GmbH, Ironwood Pharmaceuticals, Inc. A.L. Peters: Advisory Panel; Self; Abbott, Becton, Dickinson and Company, Bigfoot Biomedical, Eli Lilly and Company, Lexicon Pharmaceuticals, Inc., Livongo Health, MannKind Corporation, Medscape, Merck & Co., Inc., Omada Health, Inc., OptumRx, Inc., Sanofi US, Zafgen, Inc. Research Support; Self; AstraZeneca, Dexcom, Inc., Jaeb Center for Health Research, MannKind Corporation, National Institute of Diabetes and Digestive and Kidney Diseases. Speaker's Bureau; Self; Novo Nordisk Inc. R. Casanova: None. L.J. Cheskin: None. D. Goldman: Advisory Panel; Self; ACADIA Pharmaceuticals. Consultant; Self; Precision Health Economics. Stock/Shareholder; Self; Precision Medicine Group, Inc. Other Relationship; Self; Aspen Health Strategy Group, Celgene Corporation. Funding National Institute of Diabetes and Digestive and Kidney Diseases (R01DK107552)