What the newest prior authorization data shows

Benefily Team22 July 20269 min read

A tidy desk covered in receipts and paperwork, representing the volume of prior authorization requests insurers process each year

A denial letter rarely mentions how the odds are actually stacked. In 2024, Medicare Advantage insurers denied 7.7% of the nearly 53 million prior authorization requests submitted to them, per the newest KFF analysis of federal data, published January 2026. Only 11.5% of those denials were ever appealed — yet more than four in five appeals succeeded. That gap, a low appeal rate next to a high overturn rate, is the real story in this year's figures. This piece works through what the newest published numbers actually cover, what they don't, and what the gap means for anyone holding a denial notice.

Key takeaways

In 2024, Medicare Advantage insurers denied 7.7% of prior authorization requests — the highest share KFF has recorded since it began tracking the measure in 2019.
The rate hasn't climbed in a straight line: 5.6%–5.8% from 2019–2021, a jump to 7.4% in 2022, a dip to 6.4% in 2023, then 7.7% in 2024.
Just 11.5% of denials were appealed in 2024, but more than 80% of appeals succeeded, at least partially.
Denial rates vary hugely by service type: long-term care hospital stays were denied 65% of the time, against under 8% for all requests combined.
These figures describe Medicare Advantage medical-benefit services broadly, not Part D prescription drug denials specifically.
A federal watchdog has flagged the low-appeal, high-overturn pattern as evidence that some initial denials were not sound to begin with.

The headline number for 2024

Start with the plain figure. Medicare Advantage insurers made close to 53 million prior authorization determinations in 2024, and denied 4.1 million of them in full or in part — 7.7% of the total — according to KFF's analysis of the data CMS requires insurers to report. That's the newest full-year figure published, released in January 2026, and it's the highest denial rate KFF has recorded since it began tracking this measure in 2019.

Scope matters here before drawing any conclusions. The 7.7% describes prior authorization requests across Medicare Advantage generally: the medical benefit, covering things like inpatient stays, imaging, and skilled nursing care. It is not a Part D prescription drug denial rate, and the two shouldn't be blended together, even though Benefily's own lookup tool is built around Part D drugs specifically. More on that distinction below.

How the denial rate has actually moved since 2019

It's tempting to describe prior authorization denials as something that only ever climbs. The published run of figures is messier than that. The share of requests denied went from 5.7% in 2019 to 5.6% in 2020 and 5.8% in 2021 — essentially flat across those three years — then jumped to 7.4% in 2022. It eased back to 6.4% in 2023, before rising again to 7.7% in 2024, the highest point across the six years KFF has published. The honest description is a jump, a partial retreat, then a new high, not a smooth upward line.

2019: 5.7%
2020: 5.6%
2021: 5.8%
2022: 7.4%
2023: 6.4%
2024: 7.7%

Requests, denials, appeals and overturns at a glance

Four numbers matter more than any of the individual insurer breakdowns: how many requests were filed, how many were refused, how many of those refusals were challenged, and how many of the challenges won.

Metric	Figure	Year covered	Source
Requests submitted	Nearly 53 million (52.8 million)	2024	KFF
Requests denied, full or partial	4.1 million (7.7%)	2024	KFF
Denials appealed	11.5% of denials	2024	KFF
Appeals overturned, full or partial	More than 80% (80.7%)	2024	KFF

Medicare Advantage prior authorization, 2024 (KFF analysis of CMS data, published January 2026).

The gap between denial and appeal

“Just 11.5% of denied prior authorization requests were appealed to Medicare Advantage insurers in 2024.”
— KFF, Medicare Advantage Insurers Made Nearly 53 Million Prior Authorization Determinations in 2024

Read those two figures together and the pattern is stark. Nearly nine in ten denials are simply left unchallenged. But among the roughly one in nine that are appealed, more than 80% are overturned, at least in part. That doesn't prove nine in ten denials were wrong, since plenty of people who don't appeal have found care elsewhere, decided the stakes weren't worth the fight, or genuinely agreed with the decision. But it does mean the population of people who push back is winning far more often than not, which is worth knowing before anyone assumes a denial letter is the final word.

Which services actually see the highest denial rates

The 7.7% overall figure hides enormous variation by service type. A separate KFF analysis, published in July 2026, looked specifically at post-acute care — the stretch of recovery between a hospital stay and going home — and found denial rates far above the average.

Long-term care hospital stays: 65% of requests denied, the highest of any service KFF measured
Inpatient rehabilitation facility stays: 54% of requests denied
Skilled nursing facility stays: 12% of requests denied
All Medicare Advantage prior authorization requests combined: under 8% denied

The overturn pattern tracks the same services, and it's just as lopsided. When long-term care hospital denials were appealed, 36% were overturned; for inpatient rehabilitation, 43%; for skilled nursing facilities, 95%. That last figure caught the attention of the HHS Office of Inspector General, which separately reported that Medicare Advantage organisations overturned nearly all appealed denials for skilled nursing facility admission, and said the finding raises real questions about the quality of the initial decisions.

Reading the data correctly

The headline denial rate describes the initial decision, not a final one — a request that's later overturned on appeal is still counted among the year's original denials, so the two figures aren't in tension.
A low appeal rate doesn't mean most denials were justified. It may just mean people didn't know they could appeal, missed the window, or found another way to get care.
These are Medicare Advantage medical-benefit figures, covering things like hospital stays and skilled nursing care, not Part D prescription drug denial figures. The two report through separate systems.
A high overturn rate at the appeal stage doesn't automatically mean the first decision was wrong. Some cases succeed only once new clinical detail is added at the appeal, information the plan never had the first time round.
National averages hide wide variation between insurers, and between service types within the same insurer. A single combined percentage says very little about the plan or service you're actually dealing with.

What the gap looks like in practice

It helps to picture what an 11.5%-appealed, 80%-overturned statistic actually means for one person, so take an illustrative example rather than a documented case. Call her Linda: a Medicare Advantage enrollee whose plan denies a request to extend a skilled nursing facility stay after a hip fracture, on the grounds that she's progressed enough to go home. Like most people who receive this kind of letter, Linda doesn't appeal. She's tired, the letter is dense, and 60 days feels like plenty of time until it suddenly isn't. She pays privately for a few extra days instead, then goes home earlier than her physiotherapist recommended.

Nothing in the national figures says Linda's specific case would have been overturned. But she sat inside the group where 95% of appealed skilled nursing denials succeeded in 2024. If her case resembled the typical appealed one even loosely, filing a redetermination cost her nothing but time, and the odds were heavily in her favour. That's the practical takeaway buried in the statistics: the appeal step is where the outcome actually tends to change, and it's the step nearly everyone skips.

What this means if your own request is denied

The appeal path itself is fixed by Medicare rules, regardless of which plan you're in. The first step is a redetermination: you or your prescriber ask the plan itself to look again, usually within 60 days of the denial notice. If that doesn't change the outcome, the case moves to an independent review entity — a reviewer under contract to Medicare, entirely separate from the plan that issued the denial — and from there, larger cases can continue to an administrative law judge. Each stage has its own deadline, and each one is worth using, given how the 2024 figures actually played out.

Frequently asked questions

What is the current Medicare Advantage prior authorization denial rate?

In 2024, Medicare Advantage insurers denied 7.7% of the nearly 53 million prior authorization requests they processed, according to KFF's analysis of CMS data, published January 2026. That's the highest annual rate KFF has recorded since it started tracking the measure in 2019.

How many prior authorization appeals are successful?

Among Medicare Advantage denials that were appealed in 2024, more than 80% (80.7%) were overturned, fully or partially, per KFF. Very few denials are actually appealed in the first place: just 11.5% of them in 2024.

What's the difference between a redetermination and an independent review entity?

A redetermination is the first appeal, and it goes back to the plan that issued the denial. If the plan doesn't reverse its own decision, the case moves to an independent review entity: a reviewer under contract to Medicare, not affiliated with the plan, which looks at the case fresh.

Does the 7.7% denial rate include Part D prescription drugs?

No. That figure covers Medicare Advantage prior authorization broadly, which is dominated by medical-benefit services such as inpatient stays, imaging and skilled nursing care. Part D prescription drug prior authorization is reported through a separate process and isn't included in this figure.

Which medical services have the highest prior authorization denial rates?

Post-acute care services stand out sharply from the overall average. KFF found long-term care hospital stays denied 65% of the time and inpatient rehabilitation facility stays denied 54% of the time in 2024, against under 8% for all Medicare Advantage prior authorization requests combined.

Related on Benefily

Sources

Administrative information only. Benefily reports what a payer has published in its own prior-authorization policy as of the effective date shown. It is not medical advice, not a coverage or payment guarantee, and not an authorization. Requirements vary by plan, place of service and member benefits — always verify with the payer before rendering service.