["Health Services Research, Volume 61, Issue 3, June 2026. ", "\nABSTRACT\n\nObjective\nTo examine whether Medicare Advantage (MA) plans' provision of expanded supplemental benefits reduces enrollees' acute care utilization. Expanded supplemental benefits included non‐medical primarily health‐related (PHR) benefits such as in‐home support services, starting in 2019, and Special Supplemental Benefits for the Chronically Ill (SSBCI) such as food security and housing quality benefits, starting in 2020.\n\n\nStudy Setting and Design\nQuasi‐experimental design using staggered difference‐in‐differences models. We created indicators for offering the following benefits: Any expanded PHR, ≥ 2 expanded PHR, any SSBCI, and ≥ 2 SSBCI. Acute care utilization was measured by three binary indicators of adverse health events: annual emergency department (ED) use, hospitalizations, and re‐admissions.\n\n\nData Sources and Analytic Sample\nWe used 2017–2022 MA encounter data from a random 20% sample of enrollees. We estimated separate models for each benefit indicator, for all non‐dual and all dual‐eligible enrollees, and for highly frail patients within each non‐dual and dual‐eligible group. We used propensity score matching to balance baseline characteristics between treatment and control groups.\n\n\nPrincipal Findings\nOffering expanded supplemental benefits did not generally reduce acute care utilization in all non‐dual or all dual‐eligible enrollees. A few significant effects were relatively small or were not robust to potential differential trends between benefit‐offering and not‐offering plans. However, among highly frail non‐dual enrollees, offering any PHR reduced re‐admissions by −2.82 percentage points (95% CI: −4.78, −0.86), offering ≥ 2 expanded PHR reduced hospitalizations by −1.79 percentage points (95% CI: −2.61, −0.98) and ED use by −1.76 percentage points (95% CI: −2.38, −1.14), and offering ≥ 2 SSBCI reduced ED use by −3.51 percentage points (95% CI: −4.96, −2.05) and hospitalizations by −2.05 percentage points (95% CI: −3.12, −0.099).\n\n\nConclusions\nProvision of expanded supplemental benefits may reduce acute care utilization for certain enrollees. As spending on MA supplemental benefits rises, continued efforts are needed to assess impacts of those benefits.\n\n"]