A new study shows that close to 53 million prior authorization requests were sent to Medicare Advantage (MA) plans in 2024, increasing from 2023 and far above the number required in traditional Medicare.
Analysts at KFF said that 53 million tally rose from 49.3 million in 2023. However, the report noted that there was an average of 1.7 submissions per enrollee in 2024, down from 2023's average of 1.8 per person as enrollment in MA continues to rise.
In addition, just 625,000 prior authorization requests were submitted to the Centers for Medicare & Medicaid Services (CMS) for care provided in the original program. There is a limited set of services that are subject to prior auth in traditional Medicare, though a pilot from the CMS Innovation Center, first unveiled last June, is testing additional prior authorization requirements in the program.
That model, called Wasteful and Inappropriate Service Reduction, or WISeR, officially took effect Jan. 1.
As MA has grown—and proven quite profitable, historically—so too has scrutiny over insurers' behavior in this space. When a panel of health insurance executives appeared before two congressional committees earlier this month, prior auth and the role it can play in delaying patients' access to care was a central topic.
In poll from last summer, KFF analysts found that 73% of patients believe delays and denials of care caused by health insurers is a "major problem." In June 2025, all of the major MA insurers pledged to ease the friction associated with prior authorization, with a particular emphasis on ways technology can smooth out the process.
The new KFF report found that payers either fully or partially denied 4.1 million prior authorization requests in 2024, or 7.7% of those submitted. While far fewer requests were submitted in traditional Medicare, a larger share (22.5%) were denied, according to the report.
Of the prior authorizations that were denied, just 11.5% were appealed, KFF found. Most of these appeals, or 80.7%, were fully or partially overturned.
"These requests represent medical care that was ordered by a healthcare provider and ultimately deemed necessary but was potentially delayed because of the additional step of appealing the initial prior authorization decision," the analysts wrote. "Such delays may have negative effects on a patient’s health."
The report found that Elevance Health and Centene had the highest number of requests, averaging three requests and 2.9 requests per enrollee, respectively. Humana also came in over the average, with a mean of 2.2 requests per enrollee.
CVS Health's Aetna required an average of 1.2 requests per enrollee, while for UnitedHealthcare it was one request on average. Kaiser Permanente MA plans had the lowest number, averaging 0.6 requests per member.
UnitedHealth did have the highest rate of denials, however, at 12.8%, with Elevance at the lowest denial rate at 4.2%. Humana also came in under the average, denying 5.8% of prior authorization requests.
Kaiser Permanente plans denied 10.9% of prior auths, while Aetna denied 11.9% and Centene denied 12.3%, per the report.
Editor's note: A previous version of this story misstated the average requests per enrollee in 2024.