The three largest Medicare Advantage insurers denied prior authorization requests for long-term hospital care and inpatient rehabilitation at rates exceeding 70 percent — far above the average of their peers — according to two federal watchdog reports released in 2026 examining data from June 2024.
The reports, published by the U.S. Department of Health and Human Services’ Office of Inspector General, analyzed prior authorization decisions made by 19 Medicare Advantage organizations. UnitedHealthcare, Aetna and Humana — the three largest by enrollment — stood out for denial rates that in some categories reached 80 percent.
Denial Rates by Insurer and Care Type
For long-term care hospitals, which treat patients with complex conditions requiring extended acute care, Aetna denied 80 percent of prior authorization requests. Humana denied 72 percent and UnitedHealthcare denied 71 percent. The remaining 16 Medicare Advantage organizations in the study denied such requests at an average rate of 42 percent.
For inpatient rehabilitation facilities — which provide intensive therapy following strokes, hip fractures, and other serious medical events — UnitedHealthcare denied 66 percent of requests. Humana denied 54 percent and Aetna denied 51 percent.
A separate OIG report on skilled nursing facility admissions found that the average denial rate across all 19 insurers was 12 percent, though individual rates ranged from less than 1 percent to 23 percent. Nursing home residents faced a denial rate of 40 percent, compared with 11 percent for other enrollees — a disparity the OIG flagged as a concern warranting further investigation.
Most Appeals Succeed, Raising Questions About Initial Denials
The OIG found that when patients appealed denials, insurers reversed their decisions at striking rates. Medicare Advantage organizations collectively overturned 36 percent of long-term care hospital denials and 43 percent of inpatient rehabilitation denials on appeal. Overturn rates for individual insurers varied widely, from 14 percent to 86 percent across the 19 plans studied.
The pattern was even sharper for skilled nursing facility denials. Plans overturned 95 percent of all appealed SNF admission denials in favor of the enrollee. For requests processed by naviHealth — a subsidiary of UnitedHealth Group that handled approximately half of all SNF prior authorization decisions — the overturn rate reached 97 percent.
The OIG noted that many patients may not pursue appeals due to limited awareness of their rights or difficulty navigating the process, meaning the true scope of inappropriate denials could be substantially larger than the data captures. The reports also found that third-party contractors managing prior authorization decisions received insufficient training and oversight from the insurers that hired them.
Regulatory Context
The findings land as new federal rules on prior authorization take effect. The Centers for Medicare and Medicaid Services finalized regulations in January 2024 requiring Medicare Advantage plans to respond to urgent prior authorization requests within 72 hours and standard requests within seven calendar days. The rules, most of which took effect in 2026, also require plans to publish data on prior authorization requests, denials, and appeals on their websites — a transparency measure intended to enable better public and regulatory scrutiny.
The OIG has recommended that CMS regularly collect request-level prior authorization data, including service type and contractor information, and assess the reasons behind variations in denial and overturn rates across plans. The agency also urged investigation into the marked disparity in denial rates between nursing home residents and other Medicare Advantage enrollees.
Prior authorization requirements for post-acute care — including skilled nursing facilities, inpatient rehabilitation, and long-term care hospitals — have been a recurring focus of federal oversight. A 2022 OIG report found that some Medicare Advantage denials raised concerns about beneficiary access to medically necessary care, and Congressional scrutiny of the issue has intensified in subsequent years.
Why This Matters for Home Care
When Medicare Advantage plans deny or delay post-acute care in rehabilitation facilities and skilled nursing facilities, many patients and families turn to home care as the alternative — often before they are fully ready, and without the professional setup they need. For families navigating a hospital discharge, understanding what Medicare Advantage does and does not reliably cover for recovery is increasingly essential. SonderCare’s adjustable home hospital beds are designed to support safe recovery and rehabilitation at home; learn more at sondercare.com/beds/.
