If you've ever had a doctor call in a prescription only to find out your Medicare Advantage plan won't cover it without jumping through a series of hoops first, you've experienced prior authorization firsthand. It's one of the most frustrating features of managed care — and the Centers for Medicare & Medicaid Services (CMS) is now proposing to rein it in, at least when it comes to prescription drugs covered under Medicare Advantage plans.
Prior authorization, often abbreviated as PA, is a process where your insurance plan requires your doctor to get approval before you can fill a prescription. In theory, it's meant to ensure that expensive or potentially risky drugs are used appropriately. In practice, it can mean days or even weeks of waiting while your doctor's office faxes paperwork back and forth with your insurer — and sometimes the answer still comes back as a denial. For someone managing a chronic condition like diabetes, heart disease, or rheumatoid arthritis, that delay isn't just an inconvenience. It can mean going without medication or paying out of pocket at full price while the appeal process drags on.
CMS's proposed rule would place new guardrails on how Medicare Advantage plans — the private insurance alternative to traditional Medicare that now covers more than 33 million Americans as of 2025 — can apply prior authorization requirements to Part D prescription drugs. The proposal targets what regulators have identified as a pattern of overuse: plans requiring PA for drugs that are widely accepted as medically necessary, or applying PA requirements in ways that create unnecessary delays without meaningful clinical justification. Under the proposed framework, plans would face stricter standards for when PA can be required, how quickly decisions must be made, and how denials must be communicated to both patients and prescribing physicians.
The timing and urgency decisions are particularly important. Current federal rules already require Medicare Advantage plans to respond to standard prior authorization requests within 72 hours and urgent requests within 24 hours. But critics — including the American Medical Association and patient advocacy groups — have long argued that even these windows are too long when someone is waiting for a critical medication, and that plans sometimes exploit the process by requesting additional documentation repeatedly, effectively resetting the clock. The CMS proposal would tighten these standards and add new accountability measures for plans that have high denial rates or that routinely overturn denials on appeal, which itself signals that the initial denial may have been inappropriate.
It's worth understanding why prior authorization has become such a flashpoint specifically in Medicare Advantage, as opposed to traditional Medicare. In original Medicare (Parts A and B), prior authorization is used sparingly and primarily for certain high-cost procedures or durable medical equipment. Part D drug plans — whether standalone or bundled into a Medicare Advantage plan — do use formularies and PA requirements, but Medicare Advantage plans have historically had broader latitude to design their own utilization management tools. A 2022 report from the HHS Office of Inspector General found that Medicare Advantage plans denied 13% of prior authorization requests that met Medicare coverage rules — meaning the care was technically covered, but the plan said no anyway. That's a significant number when you consider how many prescriptions flow through these plans every year.
For beneficiaries, the practical question is: what does this mean for your prescriptions right now, in 2026? The honest answer is that proposed rules take time to finalize and implement. CMS proposals go through a public comment period, are often revised, and then plans are given time to update their systems and communications. So while this proposal signals a meaningful shift in regulatory direction, you should not assume your plan's prior authorization requirements have already changed. The most important thing you can do today is understand exactly what PA requirements apply to your current medications under your specific plan.
Every Medicare Advantage plan publishes a formulary — a list of covered drugs organized into tiers — along with a document called the Evidence of Coverage that spells out which drugs require prior authorization, step therapy (where you must try a cheaper drug first), or quantity limits. These documents are available on your plan's website and through Medicare's Plan Finder tool at Medicare.gov. If you take a brand-name medication, a specialty drug, or anything that isn't a generic, it's worth checking whether PA is required and what criteria your plan uses to approve it. Your doctor's office can also tell you whether they've had prior authorization requests denied by your plan in the past — that's useful intelligence when choosing a plan during enrollment.
Step therapy is a related issue that often gets lumped in with prior authorization discussions, and it's worth distinguishing. Step therapy requires you to try and fail on a less expensive drug before your plan will cover the one your doctor originally prescribed. CMS has previously issued guidance limiting step therapy for certain drug classes in Medicare Advantage, and the new proposal builds on that framework. If your doctor believes a specific drug is medically necessary for you — because you've already tried alternatives, or because your condition requires it — they can request a formulary exception. These exceptions are underused because many patients don't know they exist. If your plan denies coverage for a drug your doctor prescribed, ask your doctor to file a formulary exception request on your behalf. Plans are required to respond to these requests, and approval rates are often higher than people expect.
The financial stakes here are real. When a prior authorization is denied and a patient pays out of pocket for a specialty medication, costs can run into hundreds or even thousands of dollars per month. Even for more common drugs, paying cash price without insurance coverage can mean $50 to $200 or more per prescription depending on the medication. The Medicare Extra Help program — also called the Low Income Subsidy — can significantly reduce Part D drug costs for beneficiaries who qualify based on income and assets, with some enrollees paying as little as $0 to $11.20 per prescription in 2026 for covered drugs. If you're not sure whether you qualify, Social Security's website and your State Health Insurance Assistance Program (SHIP) counselor can help you apply at no cost.
Looking ahead to the Annual Enrollment Period running October 15 through December 7, 2026, prior authorization policies should be a factor in how you compare plans — not just premiums and deductibles. Medicare's Plan Finder tool allows you to enter your specific medications and see which plans cover them, at what tier, and whether PA is required. Plans with lower premiums sometimes offset that cost by applying more aggressive utilization management, including broader PA requirements. A plan that charges $0 per month in premiums but requires prior authorization for three of your five medications may end up costing you more in time, stress, and out-of-pocket spending than a plan with a modest monthly premium and a more permissive formulary.
If you want to weigh in on the CMS proposal itself, federal rulemaking includes a public comment period during which anyone — including Medicare beneficiaries — can submit comments directly to CMS. These comments are part of the official record and do influence final rule language. Visit regulations.gov and search for the relevant CMS proposed rule to find the comment submission portal. Your experience with prior authorization denials is exactly the kind of real-world evidence that regulators say they consider when finalizing rules like this one.