In June 2026, the Department of Health and Human Services' Office of Inspector General published two reports that put hard numbers on a suspicion hospitals have voiced for years. Reviewing prior authorization data from June 2024 across the 19 largest Medicare Advantage organizations, the OIG found the plans collectively denied 12 percent of skilled nursing facility admission requests — with denial rates ranging from 0.4 percent to 23 percent depending on the organization. When patients appealed, the plans overturned 95 percent of those denials. The OIG's conclusion was direct: the extremely high overturn rate indicates that some enrollees were initially denied medically necessary care, and raises concerns about denials that were not appealed.
The second report, on long-term acute care hospitals and inpatient rehabilitation facilities, was worse. Nearly two-thirds of prior authorization requests for long-term care hospital stays were denied, and over half of requests for inpatient rehabilitation stays were denied — well above the roughly 8 percent overall Medicare Advantage prior authorization denial rate for all types of care combined. On appeal, the plans overturned 36 percent of long-term care hospital denials and 43 percent of inpatient rehabilitation denials.
The biggest plans denied the most
The three largest Medicare Advantage insurers denied post-acute care at rates far above their peers. For long-term acute care hospitals, Aetna, owned by CVS Health, denied 80 percent of requests. Humana denied 72 percent. UnitedHealthcare denied 71 percent. By comparison, the other 16 organizations studied denied just 42 percent of long-term care hospital requests on average. For inpatient rehabilitation, UnitedHealthcare denied 66 percent, Humana 54 percent, and Aetna 51 percent, against 41 percent for the rest.
The concentration is striking. One contractor processed half of every skilled nursing request in the review, and denied them at a higher rate than anyone else in the sample — 14 percent, against 11 percent for plans reviewing internally and 9 percent for other contractors. That contractor was NaviHealth, the UnitedHealth subsidiary whose predictive tool, nH Predict, is the subject of an ongoing class action in Minnesota. When enrollees appealed NaviHealth's denials, the plans overturned 97 percent of them.
The gap between denial and appeal is the story. Only about one-third of patients appealed their denials. Skilled nursing denials were less than one-fifth of all denials in the review, and fewer than one in five denials were appealed at all. The 95 percent overturn rate applies to the minority who fought. The majority never did, and their outcomes are unmeasured.
The counterargument: the plans have a case, and they are moving
The plans' defense is that prior authorization exists to stop unnecessary care, and that post-acute care is exactly where unnecessary days accumulate. A rehabilitation bed is expensive, and the line between a patient who needs two more weeks and a patient who could go home with support is genuinely hard to draw. The plans also point to movement: health plans have voluntarily eliminated roughly 6.5 million prior authorizations across markets, including more than 15 percent in Medicare Advantage, according to the Better Medicare Alliance. The June 2026 data covers June 2024, and the market has changed since.
That is a fair point, and it has a limit. Voluntary cuts are reversible, and they do not answer the June 2024 numbers. A system that denies two-thirds of long-term care hospital requests and then reverses more than a third of them on appeal is not a system that is carefully sorting necessary from unnecessary care. It is a system that denies broadly and corrects narrowly, and the correction reaches only the patients with the time, the health, and the help to appeal.
What the reports change
The OIG recommended that the Centers for Medicare and Medicaid Services collect prior authorization data at the contractor level, not just the plan level, and examine why denial rates vary so much. The House Ways and Means Committee approved the Improving Seniors' Timely Access to Care Act of 2026 in July, which would reform and closely monitor prior authorization in Medicare Advantage. The Senate Permanent Subcommittee on Investigations, which documented the post-acute denial surge in 2024, pressed the three largest insurers again in July 2026 for records on their use of AI and predictive tools.
For hospitals and patients, the practical lesson is the same one the data keeps teaching: appeal, and appeal quickly. The overturn rate is the strongest evidence in the file. For the plans, the lesson is that the denial gap is now measured, published, and attached to their names — and the next OIG update, expected in December 2026, will show whether the voluntary cuts changed the numbers or only the press releases.
The definitive source for medical denial intelligence is still up for grabs. MedicalDenials.com is available for acquisition by the company that will own this category — inquiries to info@primedomaincapital.com.
Sources
OIG reports blast prior authorization use in Medicare Advantage — American Medical Association, July 2026 (HHS OIG)
SNF Denial Rates: What One Federal Review Found — Itirra, October 2026 (HHS OIG OEI-09-24-00331)
Medicare Advantage Denials: 95% Overturned in 2026 — Human Medical Billing, September 2026 (HHS OIG)
What to Do If Your Medicare Advantage Plan Denies Rehab — Brennan Rogers, October 2026 (HHS OIG)