CMS Proposes New Rules to Rein In Prior Authorization for Medicare Drug Coverage

If you've ever had a pharmacist tell you that your insurance plan needs to 'authorize' a medication your doctor just prescribed — and then waited days or even weeks to find out if you'd get it — you've experienced prior authorization firsthand. It's one of the most frustrating aspects of Medicare Advantage coverage, and it's the subject of a significant proposed rule from the Centers for Medicare & Medicaid Services (CMS) that could change how plans manage your access to prescription drugs. Understanding what's being proposed, why it matters, and how it might affect your coverage decisions is essential for any Medicare beneficiary enrolled in — or considering — a Medicare Advantage plan.

Prior authorization, often abbreviated as PA, is a process that Medicare Advantage plans use to control costs and manage drug utilization. Before your pharmacy can dispense certain medications, the plan requires your doctor to submit documentation proving the drug is medically necessary. In theory, this is a cost-containment tool. In practice, it can delay critical medications for days, require multiple phone calls between your doctor's office and the insurance plan, and sometimes result in outright denials that must be appealed. The problem has grown significantly as Medicare Advantage enrollment has surged — according to CMS.gov data, more than 33 million beneficiaries were enrolled in Medicare Advantage plans in 2024, representing over 54% of all Medicare-eligible individuals. With that many people in managed care plans, the scale of prior authorization delays has become a genuine public health concern.

The CMS proposed rule takes direct aim at several specific practices that beneficiaries and physicians have long complained about. First, it would establish hard deadlines for plan responses: urgent prior authorization requests would need to be decided within 24 hours, and non-urgent standard requests within 72 hours. Currently, plans can take up to 14 days to respond to standard requests under existing regulations, and while many plans respond faster, there is no enforceable minimum that protects you if your plan drags its feet. For someone waiting on a blood thinner, an antidepressant, or a cancer medication, the difference between 72 hours and 14 days is not a bureaucratic footnote — it's a real gap in care.

Another major component of the proposed rule addresses a practice called step therapy, sometimes called 'fail first' protocols. Under step therapy, a plan can require you to try a less expensive drug — often a generic or an older medication — before it will cover the drug your doctor actually prescribed. If the cheaper drug doesn't work or causes side effects, you then have to document that failure before the plan will authorize the original prescription. The proposed rule would not eliminate step therapy entirely, but it would require plans to grant exceptions more quickly and would prohibit plans from applying step therapy requirements to drugs that a patient is already stabilized on. That last point is particularly important for beneficiaries managing chronic conditions like rheumatoid arthritis, epilepsy, or bipolar disorder, where switching medications mid-treatment can cause serious setbacks.

The proposed rule also introduces new transparency requirements that could directly affect how you shop for a Medicare Advantage plan. Plans would be required to publicly report their prior authorization approval and denial rates, broken down by drug class and therapeutic category. This data would need to be submitted to CMS and made available to the public. Right now, it's nearly impossible for a beneficiary comparing plans during the Annual Enrollment Period — which runs October 15 through December 7 each year — to know how often a given plan denies prior authorization requests for the type of medications they take. If this rule is finalized, that information could become a meaningful factor in plan selection, sitting alongside premium costs, deductibles, and star ratings.

According to CMS.gov data, the average Medicare Advantage plan in 2024 carried a $0 monthly premium for medical coverage, but that headline number can obscure significant variation in drug coverage costs and access restrictions. The Medicare Plan Finder tool at Medicare.gov allows beneficiaries to enter their specific medications and compare how different plans cover them, including whether prior authorization is required. Under the proposed rule, that comparison would become even more informative, because you'd also be able to see how often a plan actually approves those authorizations once requested. A plan that requires PA for your cholesterol medication but approves 97% of requests is very different from one that approves only 60% — and right now, you have no easy way to know which type of plan you're enrolling in.

It's worth understanding how this proposed rule fits into the broader regulatory landscape. Medicare Advantage plans are required to cover all drugs that Original Medicare Part B covers, but their Part D drug formularies — the lists of covered prescription drugs — are managed by the plans themselves within CMS guidelines. Plans have significant latitude to place drugs on different formulary tiers, require prior authorization, and impose quantity limits. The proposed rule doesn't eliminate that latitude, but it creates a floor of consumer protections that all plans must meet. Think of it like building codes: contractors can build houses in many different styles, but they all have to meet minimum safety standards. This rule would establish minimum standards for how quickly and fairly plans must process your medication requests.

For beneficiaries who have already experienced prior authorization denials, the proposed rule also strengthens the appeals process. Currently, if your plan denies a prior authorization request, you have the right to appeal — but the process can be confusing and time-consuming. The proposed rule would require plans to provide clearer written explanations of denials, including the specific clinical criteria that were not met, and would require that denial notices include plain-language instructions for filing an appeal. This matters because studies have consistently shown that a significant percentage of prior authorization denials are overturned on appeal — meaning the original denial was incorrect — but many beneficiaries never appeal because they don't know how or find the process too daunting.

If you're currently enrolled in a Medicare Advantage plan and take medications that require prior authorization, there are practical steps you can take right now regardless of when or whether this rule is finalized. First, ask your doctor's office to keep copies of all prior authorization submissions and track response timelines. If a plan exceeds the current regulatory deadlines, that's a reportable violation. Second, if you receive a denial, request the specific clinical criteria the plan used to make that decision — you're entitled to that information under existing law. Third, during the next Annual Enrollment Period, use Medicare.gov's Plan Finder to check whether your medications require prior authorization under different plans in your area. Switching to a plan with fewer PA requirements for your specific drugs may save you significant time and frustration, even if the premium is slightly higher.

The proposed rule is not yet final, and the regulatory process allows for a public comment period during which insurance plans, physician groups, patient advocates, and individual beneficiaries can submit feedback to CMS. Historically, proposed rules of this type go through multiple rounds of revision before being finalized, and the final version may differ from what was initially proposed. Some provisions may be strengthened, others may be scaled back in response to industry comments. The timeline for finalization can vary, but CMS typically aims to finalize rules affecting Medicare Advantage plan operations well before the Annual Enrollment Period so that plans can incorporate the changes into their benefit designs for the following year.

Data Snapshot: According to CMS.gov data from the 2024 Medicare Advantage and Part D Star Ratings dataset, CMS evaluated prior authorization and utilization management practices as part of its plan oversight metrics. In 2024, there were approximately 7,900 Medicare Advantage plan options available nationwide across all plan types, including HMOs, PPOs, and PFFS plans. The sheer volume of plan options — which varies significantly by state, with states like Florida and California offering hundreds of local plan choices while rural states may offer fewer than 20 — underscores why standardized prior authorization rules matter: without a federal floor, beneficiary protections vary wildly depending on which plan and which state you happen to be in.

For beneficiaries in states with strong consumer protection laws, some of these proposed federal standards may already be partially in place at the state level. Several states have enacted their own prior authorization reform laws that impose faster response timelines or limit step therapy requirements for state-regulated insurance products. However, Medicare Advantage plans are federally regulated, which means state prior authorization laws often do not apply to them — making federal action through CMS the primary lever for reform. This is precisely why the proposed rule carries such significance: it would apply uniformly to every Medicare Advantage plan in every state, creating a consistent baseline of protection for all 33 million-plus beneficiaries in managed care.

The bottom line for Medicare beneficiaries is this: prior authorization is a real and consequential feature of Medicare Advantage coverage that affects your ability to get the medications your doctor prescribes. The proposed CMS rule represents a meaningful attempt to make that process faster, fairer, and more transparent. Whether you're currently enrolled in Medicare Advantage or considering it during the next enrollment period, paying attention to how this rule develops — and how your specific plan handles prior authorization — can directly affect your health and your wallet. Check Medicare.gov regularly for updates to plan information, and if you have concerns about a prior authorization denial, contact 1-800-MEDICARE (1-800-633-4227) to understand your rights and options.