Does Original Medicare Require Prior Authorization?

Short answer: for most care, Original Medicare still does not ask for approval in advance. For a short list of services and equipment, it does. Some hospital outpatient procedures have needed it nationwide since 2020. A CMS model called WISeR added it for selected services in six states, including Washington, starting January 1, 2026. And on October 28, 2026, more braces, an ultralightweight wheelchair and a specialty bed join the national equipment list. If you have a Medicare Supplement, your Medigap plan does not add a step of its own, but it does follow Medicare's decision.

Prior authorization means your doctor or supplier asks Medicare to confirm a service or item is covered before you get it. Medicare Advantage plans use it widely. Original Medicare uses it in three places, and only the last one is still ahead.

• Certain hospital outpatient procedures, nationwide, since July 1, 2020. The first group was blepharoplasty (eyelid surgery), botulinum toxin injections, panniculectomy, rhinoplasty and vein ablation. Implanted spinal neurostimulators and cervical fusion with disc removal were added in July 2021, and facet joint interventions in July 2023.
• The WISeR model, in six states, since January 1, 2026. Washington is one of them. More on it below.
• Durable medical equipment, starting October 28, 2026. CMS published a notice on July 30, 2026 adding eight braces, wheelchair and bed codes to its Required Prior Authorization List.

None of this changes what Medicare covers. It changes the paperwork that has to happen before certain things are paid for, and it puts that paperwork on your provider, not on you.

WISeR stands for Wasteful and Inappropriate Service Reduction. It is a CMS model that runs from January 1, 2026 to December 31, 2031 in Washington, New Jersey, Ohio, Oklahoma, Texas and Arizona. For a selected set of Original Medicare services, it adds a prior authorization step, or a review before the claim is paid. CMS names examples such as skin and tissue substitutes, electrical nerve stimulator implants, and knee arthroscopy for knee osteoarthritis. The complete list lives in CMS's WISeR operational guide.

Here is what stays the same, straight from CMS's own answers about the model:

• You don't file anything. Your provider handles the request. You are not expected to take action.
• A person reviews every denial. CMS requires a human clinician with relevant expertise to review every non-affirmation. It cannot be made by software alone.
• Your appeal rights are unchanged. You and your provider can appeal any denied claim.
• You are told before you are billed. If a service is not approved and the provider still plans to give it to you, they must give you an Advance Beneficiary Notice of Non-Coverage first.
• Medicare Advantage is out of scope. CMS says WISeR does not apply to people with Medicare Advantage and will have no impact on them.

Two things are worth knowing if a procedure is on your calendar. A provider can choose not to request prior authorization, and in that case the claim is reviewed before Medicare pays it. And two services were pulled back in April 2026 "until a future date": deep brain stimulation for essential tremor and Parkinson's disease, and percutaneous image-guided lumbar decompression for spinal stenosis.

Medicare already keeps a list of equipment that needs prior authorization before a supplier is paid. The July 30, 2026 notice adds eight more items to it:

• An air-fluidized bed (E0194)
• An ultralightweight manual wheelchair (K0005)
• An off-the-shelf knee brace with adjustable joints (L1833)
• Three back braces, thoracic-lumbar-sacral orthoses (L0456, L0457, L0486)
• An elbow brace (L3761) and a wrist-hand brace (L3916)

Everything except the two arm braces starts October 28, 2026. The arm braces phase in by state: New York, Michigan, Florida and California first, on October 28. Pennsylvania, Massachusetts, Ohio, Illinois, Texas, Georgia, Arizona and Oregon join on January 26, 2027. Every remaining state, Washington included, follows on April 26, 2027.

The same notice adds 22 codes, among them more braces, wheelchairs and home ventilators, to a separate list. For those, your treating practitioner must have seen you within the six months before writing the order, and the written order must reach the supplier before delivery. In practice: expect a recent appointment to be part of getting a brace or wheelchair.

That second reason matters to you directly. If someone calls offering a "free" brace in exchange for your Medicare number, the new rule is one more reason it is not what it sounds like. We wrote a separate guide on the three Medicare calls to hang up on.

A Medigap policy pays after Medicare pays its share of the Medicare-approved amount. The Medigap insurer does not run its own prior authorization, so when Original Medicare requires approval for something, that Medicare step decides it and your supplement follows. You still see any provider who accepts Medicare, you still need no referrals, and for the vast majority of care nothing about that has changed.

What has changed is the comparison people use when choosing between the two paths. "Medicare Advantage has prior authorization and Original Medicare doesn't" was a fair shorthand. The accurate version today: Medicare Advantage plans set their own prior authorization rules, which can reach much further, while Original Medicare uses it for a short, published list of services and equipment. That is still a real difference. It is just not the all-or-nothing difference it used to be.

If you are weighing the two this fall, our side-by-side of Medicare Advantage vs Medicare Supplement walks through the rest of the trade-off.

• Ask early. If a procedure, brace or wheelchair is coming up, ask your provider whether it needs prior authorization and how long they expect it to take.
• Keep your appointments current. For equipment on that second list, your practitioner must have seen you within the six months before the order.
• Read anything you are asked to sign. An Advance Beneficiary Notice means the provider expects Medicare may not pay. You get to decide before the service, not after.
• Appeal if you disagree. A denial is not the end of the road, and your rights to appeal are the same as before.
• Call 1-800-MEDICARE (1-800-633-4227) if something is stuck. CMS has said it can suspend the equipment program if it becomes a barrier to care.

Most people will never run into any of this. The ones who do tend to find out at the worst moment, with a brace on back order or a procedure date that slips. If you would like someone to look at how your own coverage handles the things you actually use, our licensed agents will do it by phone or video at no cost.

The Annual Enrollment Period runs October 15 to December 7, and it is the one time each year most people can change plans. A review before then leaves room to decide without a deadline pressing on you.

Related reading: Medicare scam calls about braces, wheelchairs and hospice, Medicare Advantage vs Medicare Supplement, or how a Medicare Supplement works.