Dual-eligible enrollees who use Medicaid-funded long-term services and supports (LTSS) often face care fragmentation between Medicare and Medicaid benefits. One strategy to improve care coordination is for dual-eligible LTSS users to have both Medicare and Medicaid plans administered by a single insurer. When a single insurer manages both plans, it may have greater financial incentive and operational capacity to coordinate care between programs. Using 2018-21 nationwide Medicare Advantage encounter data and Medicaid claims, we assessed the association between same-insurer coverage and health care use among dual-eligible LTSS users ages sixty-five and older. We found that same-insurer coverage was associated with a lower probability of hospitalization and a higher number of outpatient visits. Our results suggest that same-insurer coverage can reduce acute care use among dual-eligible LTSS users, potentially by improving access to outpatient visits. They support the Centers for Medicare and Medicaid Services' policy direction toward aligning Medicare and Medicaid coverage under the same insurer.