Federal Watchdog: The Three Largest Medicare Advantage Insurers Denied Long-Term Hospital Requests More Than 70 Percent of the Time

The three largest Medicare Advantage insurers by enrollment denied prior authorization requests for admission to long-term acute care hospitals more than 70 percent of the time, the highest rates among the 19 Medicare Advantage organizations studied, according to a federal data brief published in June 2026. The Office of Inspector General identified the three organizations as UnitedHealthcare, Humana, and CVS Health.

The review covered prior authorization determinations made in June 2024. Among all 19 organizations, the three largest also had some of the highest denial rates for inpatient rehabilitation facility admission requests.

When patients appealed the initial denials, outcomes improved substantially. Medicare Advantage organizations collectively overturned 36 percent of the denied long-term acute care hospital requests and 43 percent of denied inpatient rehabilitation requests on appeal. The OIG noted that high overturn rates on appeal can indicate that some initial denials may not have been well supported by medical necessity criteria.

All three organizations with the highest denial rates operated exclusively for-profit Medicare Advantage contracts at the time of the review. The data brief did not determine whether any specific denial was inappropriate, but recommended continued oversight of denial patterns at the plan and organization level.

For Medicare Advantage enrollees who are denied long-term acute care or rehabilitation coverage, federal rules provide the right to a fast appeal. A written denial must include information on how to request an immediate review.