If you are enrolled in a Medicare Advantage plan — and roughly 33 million Americans are — there is a good chance you have already run into prior authorization, or you will. It is the process your plan uses to decide whether it will approve and pay for a specific treatment, procedure, drug, or service before you receive it. In theory, it is a cost-management tool. In practice, for millions of seniors, it has become a barrier between them and the care their doctors have already decided they need. The federal government recognized this problem and tried to fix it with new rules that took effect in 2024. But the early results suggest the fix is not working nearly as well as regulators hoped.
Prior authorization has been a feature of Medicare Advantage plans for years, but its use expanded dramatically over the past decade as insurers discovered it was an effective way to reduce costs. The problem is that reducing costs and reducing unnecessary care are not always the same thing. A 2022 report from the HHS Office of Inspector General found that Medicare Advantage plans denied 13 percent of prior authorization requests that met Medicare coverage rules — meaning those services should have been approved under traditional Medicare without any additional review. That finding was a turning point. It confirmed what patient advocates and physicians had been saying for years: prior authorization was being used to deny care that beneficiaries were legally entitled to receive.
In response, the Centers for Medicare and Medicaid Services finalized a sweeping prior authorization rule in early 2024 that set binding timelines for how quickly plans must respond to requests. For urgent or expedited prior authorization requests — situations where waiting could seriously harm a patient — plans must now respond within 72 hours. For standard, non-urgent requests, the deadline is seven calendar days. Before this rule, plans could take up to 14 days on standard requests, and the delays were frequently longer in practice. CMS also required plans to provide specific clinical reasons when denying a request, rather than vague boilerplate language that made it nearly impossible for a patient or doctor to understand why care was refused or how to appeal effectively.
According to CMS.gov data, Medicare Advantage plans submitted more than 46 million prior authorization requests in 2021 alone, and that number has grown each year since. The sheer volume of requests creates enormous pressure on plan review systems, and critics argue that many plans use automated algorithms — rather than licensed clinicians — to make initial denial decisions. CMS's 2024 rule attempted to address this by requiring that any denial based on clinical criteria must be reviewed by a physician or other qualified clinician with expertise in the relevant specialty. Whether plans are actually following this requirement in practice is a different question, and one that regulators are still working to answer.
The early evidence from 2024 and into 2025 suggests compliance has been inconsistent. Physician groups, hospital associations, and patient advocacy organizations began documenting cases almost immediately after the new rules took effect where plans were still issuing denials without adequate clinical justification, still missing the 72-hour window on urgent requests, and still using denial language so generic that beneficiaries could not meaningfully respond. Part of the problem is enforcement. CMS has the authority to sanction Medicare Advantage plans that violate prior authorization rules, including suspending their ability to enroll new members, but the agency has historically been slow to use its most aggressive enforcement tools. Plans that know enforcement is unlikely have less incentive to change their internal processes.
The services most frequently caught up in prior authorization delays are also the ones seniors need most urgently after a health crisis. Skilled nursing facility care following a hospital stay, home health services, inpatient rehabilitation, and durable medical equipment like wheelchairs and oxygen concentrators are among the most commonly delayed or denied categories. When a 72-year-old recovering from a hip replacement is discharged from the hospital and her Medicare Advantage plan takes five days to approve the skilled nursing facility her doctor recommended, the consequences are not abstract. She may be sent home before she is ready, increasing her risk of falls, complications, and readmission. These are the real-world stakes of a bureaucratic process that is not working as intended.
Data Snapshot: According to CMS.gov data published in its Medicare Advantage and Part D Contract and Enrollment data files, there were 3,959 Medicare Advantage plan options available to beneficiaries nationwide in 2024, across hundreds of different insurers and plan types. Among those plans, star ratings — CMS's quality scoring system on a 1-to-5 scale — showed that only about 31 percent of Medicare Advantage enrollees were in plans rated 4 stars or higher in 2024, down from prior years. Star ratings incorporate prior authorization and appeals metrics, meaning a plan's handling of these processes directly affects its score. Beneficiaries can check their plan's star rating at Medicare.gov/plan-compare to get a sense of how their insurer performs on care access measures.
If you are currently in a Medicare Advantage plan and have had a prior authorization request denied, you have specific rights that many beneficiaries do not know about. First, you can request an expedited appeal, which requires the plan to respond within 72 hours. To qualify for expedited review, you or your doctor must explain that waiting the standard timeframe could seriously harm your health. Second, if the plan upholds its denial on internal appeal, you can escalate to an independent review organization — a third party not affiliated with your insurer — which is required to make a decision within 72 hours for expedited cases. Third, if you are still denied, you can continue escalating through the Medicare appeals process, which has five levels total, including review by an Administrative Law Judge and ultimately federal court. The majority of prior authorization denials that are appealed are overturned, which itself tells you something important about the quality of the original denial decisions.
For beneficiaries who are shopping for a Medicare Advantage plan during the Annual Enrollment Period — which runs October 15 through December 7 each year — prior authorization policies should be a serious factor in your decision, not an afterthought. Before enrolling in any plan, you can request its Evidence of Coverage document, which lists every service that requires prior authorization. Some plans require it for dozens of services; others use it more selectively. You can also look at the plan's appeals and grievance data, which CMS publishes annually. A plan with a high rate of prior authorization denials and a low rate of successful appeals is a warning sign worth taking seriously, particularly if you have chronic conditions or anticipate needing specialist care, surgery, or post-acute services.
It is also worth understanding how prior authorization works differently in Medicare Advantage versus traditional Medicare. In original Medicare — Parts A and B — prior authorization is used for a very limited set of services, primarily certain outpatient hospital procedures and some imaging. For the vast majority of services, your doctor orders the care and Medicare pays. There is no insurance company in the middle deciding whether your doctor's clinical judgment is correct. That is a fundamental structural difference between the two systems, and it is one reason some beneficiaries with complex medical needs choose to remain in traditional Medicare paired with a Medigap supplemental policy, even though Medicare Advantage plans often have lower premiums and added benefits like dental and vision coverage.
Medigap plans — also called Medicare Supplement Insurance — do not use prior authorization at all. If Medicare covers a service, your Medigap plan pays its share of the cost without requiring advance approval. The tradeoff is that Medigap premiums can be substantial. Plan G, currently the most popular Medigap option for new enrollees, typically costs between $100 and $300 per month depending on your age, location, and the insurer, with significant variation by state. In high-cost states like New York or California, premiums can run higher. But for beneficiaries who use a lot of healthcare — those managing cancer, heart disease, diabetes with complications, or other serious conditions — the absence of prior authorization barriers can be worth the higher monthly cost.
CMS has signaled that it intends to continue tightening prior authorization rules in Medicare Advantage, and there is bipartisan support in Congress for legislation that would go further than the 2024 rule. The Improving Seniors' Timely Access to Care Act, which passed the House with overwhelming bipartisan support, would codify many of the 2024 CMS requirements into law and add new transparency and enforcement mechanisms. As of mid-2026, the Senate has not yet passed a companion bill, but advocacy pressure from physician groups, hospital systems, and patient organizations has kept the issue on the legislative agenda. Beneficiaries who want to make their voices heard can contact their senators directly or through organizations like AARP, which has made prior authorization reform a legislative priority.
The bottom line for Medicare beneficiaries right now is this: prior authorization is a real obstacle in Medicare Advantage, the new federal rules have helped at the margins but have not solved the problem, and you need to know your rights before you need to use them. Keep a copy of your plan's prior authorization requirements. Ask your doctor's office to submit requests as early as possible and to flag urgent cases for expedited review. If you receive a denial, do not accept it as final — appeal immediately, ask your doctor to write a letter of medical necessity, and escalate if needed. And when open enrollment comes around each fall, treat a plan's prior authorization track record as seriously as you treat its premium or its drug formulary. The plan that looks cheapest on paper may cost you far more in delayed care when it matters most.