53 Million Prior Auth Requests: What Medicare Advantage Delays Cost You

If you're enrolled in a Medicare Advantage plan, there's a good chance you've already encountered prior authorization — or you will. It's the process where your insurer must approve certain treatments, procedures, medications, or specialist visits before you receive them. In 2024, Medicare Advantage insurers made nearly 53 million prior authorization determinations, according to data analyzed by KFF, the nonpartisan health policy research organization. That staggering number — roughly one authorization request for every two Medicare Advantage enrollees in the country — puts a sharp spotlight on a system that critics say too often stands between seniors and the care their doctors have ordered.

Prior authorization exists, in theory, to prevent unnecessary or duplicative care and to control costs. Insurers argue it's a necessary tool for managing the clinical and financial risks of covering a large population. But the sheer scale of 53 million determinations in a single year raises a practical question every Medicare Advantage enrollee should be asking: how often does this process delay or deny care that is medically necessary? The answer, based on available data, is more often than most beneficiaries realize. Denial rates across Medicare Advantage plans have drawn scrutiny from Congress, the HHS Office of Inspector General, and CMS itself, with federal investigators finding in prior years that a notable share of denied claims would likely have been approved under traditional Medicare — which does not use prior authorization for most services.

Here's how prior authorization actually works in practice. Your doctor recommends an MRI, a course of physical therapy, a specialty drug, or an inpatient hospital stay. Before you can receive that service, your doctor's office must submit a request to your Medicare Advantage insurer with supporting clinical documentation. The insurer then reviews the request — sometimes using automated algorithms, sometimes using clinical staff — and issues an approval, a denial, or a request for more information. Under rules that took effect in 2024, Medicare Advantage plans are required to respond to standard prior authorization requests within 7 calendar days, and to urgent requests within 72 hours. That's an improvement over previous timelines, but a week's wait for a cancer scan or a cardiac procedure can feel very long when you're the patient waiting.

What happens when a prior authorization is denied? This is where beneficiaries have more power than many realize — but only if they know to use it. You have the right to appeal any denial through your Medicare Advantage plan's internal appeals process, and if that fails, through an independent review organization. The data on appeals is instructive: beneficiaries and providers who appeal prior authorization denials overturn them at meaningful rates, which suggests that a portion of initial denials are not clinically sound. The OIG has previously found that Medicare Advantage plans sometimes denied requests that met Medicare coverage criteria, meaning the denial wasn't about whether the care was appropriate — it was about the insurer's internal review process. If your doctor believes a denial is wrong, push back. Request a peer-to-peer review, where your physician speaks directly with the insurer's medical reviewer. This step alone overturns a significant number of denials before a formal appeal is even filed.

CMS has been tightening the rules around prior authorization in Medicare Advantage, and beneficiaries should understand what protections are now in place. The Interoperability and Prior Authorization Final Rule, which CMS finalized in early 2024, requires Medicare Advantage plans to send prior authorization decisions electronically, provide specific reasons for denials, and report prior authorization metrics publicly starting in 2026. That last requirement — public reporting — is significant. For the first time, beneficiaries will be able to compare plans not just on premiums and star ratings, but on how often they deny care and how long those decisions take. When shopping during the Annual Enrollment Period, which runs October 15 through December 7 each year, that data could become one of the most important factors in choosing a plan.

Not all Medicare Advantage plans use prior authorization at the same rate or with the same outcomes. Large national insurers, regional HMOs, and PPO plans all have different utilization management philosophies. HMO-style Medicare Advantage plans, which require you to use a network of providers and typically require referrals for specialists, tend to have more extensive prior authorization requirements than PPO plans, which offer more flexibility. In 2025, the average Medicare Advantage enrollee paid a monthly premium of around $17 to $18 for their plan beyond the standard Part B premium of $185 per month — but low premiums can come with higher utilization management burdens. A plan with a $0 premium that denies one in five prior authorization requests may cost you far more in delayed care, out-of-pocket costs for denied services, and stress than a plan with a modest monthly premium and a more permissive authorization process.

For beneficiaries who find prior authorization burdensome, traditional Medicare — Original Medicare Parts A and B — remains an alternative that does not use prior authorization for most covered services. However, Original Medicare does not cap your out-of-pocket costs, which is why most people who choose it also purchase a Medigap supplemental policy. Medigap plans, sold by private insurers, cover costs like deductibles and coinsurance, and they do not use prior authorization. In 2025, Medigap Plan G, one of the most comprehensive options, typically costs between $100 and $200 per month depending on your age, location, and insurer — but it provides coverage without the authorization hurdles that Medicare Advantage plans impose. If you're currently in Medicare Advantage and want to switch to Original Medicare plus Medigap, the Annual Enrollment Period (October 15–December 7) allows you to drop your Advantage plan, but getting a Medigap policy may require medical underwriting unless you live in a state with guaranteed issue protections.

Speaking of state protections: if you live in California, Idaho, Illinois, Kentucky, Louisiana, Maine, Maryland, Missouri, Nevada, New Jersey, New York, Oklahoma, or Oregon, you benefit from a birthday rule that gives you a 30-day window around your birthday each year to switch Medigap plans without medical underwriting. This means even if you have pre-existing conditions, you can move to a different Medigap plan during that window without being denied or charged higher premiums based on your health history. For beneficiaries in these states who are frustrated with prior authorization in Medicare Advantage, the birthday rule creates a meaningful annual opportunity to explore a switch to Original Medicare with Medigap coverage.

The 53 million prior authorization determinations made in 2024 are not just a policy statistic — they represent 53 million moments when a Medicare Advantage enrollee's access to care was subject to an insurer's approval. Some of those determinations were routine and resolved quickly. Others involved seriously ill patients waiting days for approval of urgent treatments. As CMS moves toward requiring public reporting of prior authorization data by plan, beneficiaries will gain new tools to hold insurers accountable. In the meantime, the most important thing you can do is know your rights: request peer-to-peer reviews, file appeals when care is denied, and during every enrollment period, look beyond the premium to ask how often a plan says no — and how quickly it says yes.