Medicare will require prior approval for certain procedures starting in 2026, when a new CMS pilot program adds a short list of outpatient services to the approval process in select states. Most Medicare-covered care still doesn't need advance sign-off, but the list of exceptions is growing, and it's worth knowing where your care might fall.
What Prior Authorization Means for Your Medicare Coverage
Prior authorization means your doctor or hospital has to get approval from Medicare, or from a Medicare Advantage plan, before performing a specific service. If approval isn't obtained first, the claim can be delayed or denied, even if the care itself was medically reasonable.
For most of Medicare's history, this concept barely applied to Original Medicare (Part A and Part B). You could generally get a covered service and Medicare would pay its share afterward, with no advance paperwork required. Medicare Advantage (Part C) has worked differently for years, with many plans requiring prior authorization for a long list of services as a routine part of how they manage costs.
That gap between Original Medicare and Medicare Advantage is starting to narrow, at least in a limited way.
Original Medicare vs. Medicare Advantage: Two Different Systems
It helps to separate the two paths clearly:
- Original Medicare is run directly by the federal government. Historically, prior authorization applied to only a small number of outpatient hospital services.
- Medicare Advantage plans are sold by private insurance companies. These plans have broad flexibility to require prior authorization for many services, from imaging to skilled nursing stays to certain surgeries, as long as the plan follows Medicare's coverage rules.
If you're comparing your options, this is one of the bigger differences between the two paths. Our Medicare Supplement Guide 2026 walks through how Original Medicare paired with a Medigap policy avoids most of the network and approval hurdles that come with many Advantage plans.
Procedures That Already Require Prior Approval Under Original Medicare
Before the newest changes, Original Medicare already required prior authorization for a specific set of outpatient hospital department services. These were added gradually starting in 2020 because CMS found the services were being overused or billed at unusually high rates. They include things like:
- Blepharoplasty (eyelid surgery)
- Botulinum toxin injections
- Panniculectomy (removal of excess abdominal skin)
- Rhinoplasty
- Vein ablation for varicose veins
- Cervical fusion with disc arthroplasty
- Implanted spinal neurostimulators
Notice a pattern: these are mostly elective or cosmetic-adjacent outpatient procedures, not emergency care, not inpatient hospital stays, and not routine visits. That pattern matters, because it shows CMS has generally used prior authorization as a targeted tool rather than a blanket requirement.
What's New: CMS Is Testing Prior Authorization in Original Medicare
CMS has announced a new pilot, sometimes referred to by the acronym WISeR, set to begin in 2026 in a handful of states. Under this model, certain outpatient procedures performed under Original Medicare will need prior approval before the claim is paid, using a review process that includes outside technology companies working alongside Medicare.
The services being tested tend to fall into categories CMS has flagged for potential overuse or fraud risk, such as certain skin substitute grafts, select spinal procedures, and some nerve stimulator implants. The pilot is not a nationwide, all-services requirement. Emergency services, inpatient hospital care, and most routine outpatient visits are not part of this pilot.
Because this program is limited to specific states and a defined list of services, not everyone on Original Medicare will notice a difference. If you live in one of the affected states and your doctor recommends a procedure on the list, your provider's office will be the one handling the prior authorization request, not you directly. Still, it's smart to ask your doctor's office whether a planned procedure falls under this pilot before you schedule it.
How Prior Authorization Rules Could Affect You
Let's say Marcus is 68, enrolled in Original Medicare with a Medigap policy, and lives in one of the pilot states. His doctor recommends a spinal procedure that happens to be on the new prior authorization list. Before the pilot, his doctor's office would have scheduled the procedure and billed Medicare afterward. Now, the office has to submit documentation ahead of time and wait for approval before the surgery date is confirmed.
For Marcus, this could mean a short delay of a few days to a couple of weeks while the paperwork is reviewed, depending on how quickly his provider submits the request and how the review process moves. It doesn't change what Medicare covers. It changes the order of operations: approval comes before the procedure instead of the claim being reviewed after the fact.
This is the kind of change that rarely shows up in a beneficiary's mailbox as a big announcement. It shows up as a phone call from a scheduling coordinator saying, "we need to get this approved first."
What to Do If Your Procedure Needs Prior Approval
If your doctor mentions that a procedure needs prior authorization, a few steps can keep things moving smoothly:
- Ask early. If a procedure is being planned weeks or months in advance, ask your provider's office whether prior authorization applies, and if so, when they plan to submit the request.
- Confirm documentation is complete. Denials are often caused by missing medical records rather than the service being uncovered outright.
- Know your appeal rights. If a request is denied, both Original Medicare and Medicare Advantage plans have a formal appeals process. You have the right to ask for reconsideration.
- Keep your own paper trail. Save any letters or portal messages about the authorization status in case you need to reference them later.
If you're unsure whether your current plan handles prior authorization differently than you expected, our Understanding Medicare Costs article covers how coverage decisions can affect what you end up paying out of pocket.
Prior Authorization and Medicare Advantage Plans
While the Original Medicare pilot is new and narrow, prior authorization has been a standard feature of Medicare Advantage plans for a long time. Depending on the plan, prior authorization can apply to imaging like MRIs and CT scans, certain surgeries, skilled nursing facility stays, durable medical equipment, and more. Rules vary significantly from one plan and one carrier to another, which is part of why it's worth comparing plan documents carefully rather than assuming all Medicare Advantage plans work the same way.
If you're weighing Original Medicare against Medicare Advantage, or trying to decide when to make a change, timing matters. Our When to Enroll in Medicare guide covers the enrollment windows that apply if you want to switch paths or adjust your coverage.
The broader takeaway is this: prior authorization isn't disappearing, and in some corners of Medicare it's expanding. Whether you're in Original Medicare or a Medicare Advantage plan, knowing which services on your specific plan or in your specific pilot state require advance approval can save you a scheduling headache later.