Does Medicare Require Prior Authorization for Physical Therapy?

Does Medicare require prior authorization for physical therapy?

No, not for outpatient physical therapy under Original Medicare. Medicare Advantage is a different story. Most Advantage plans do require prior authorization for therapy, and each plan sets its own rules, so the answer depends on which kind of Medicare the patient carries.

Original Medicare proves medical necessity a different way, and CMS sets those rules nationally. A physician or other qualified provider certifies the plan of care.¹ You write a progress report at least every 10 treatment days.² And once the patient’s therapy charges pass a yearly threshold, you add the KX modifier to the claim.³ The KX modifier isn’t an approval either. It’s your attestation that the documentation in the chart supports continued care. There’s no request to submit, no approval to wait on, and no visit count handed to you up front. Under Original Medicare, the documentation is the authorization.

Original Medicare vs Medicare Advantage

On the Original Medicare side, certification is the piece that matters. The plan of care has to be certified within 30 days of the first day of treatment, counting the evaluation, and recertified at least every 90 days after that.⁴

On the Advantage side there’s no national answer to give you. Each plan sets its own visit counts, date ranges and renewal process. That’s why the insurance card matters. Check at intake which one the patient has, because everything downstream depends on it.

Does physical therapy require prior authorization?

It depends on the payer. Original Medicare doesn’t require it for outpatient PT. Most Medicare Advantage plans and many commercial plans do. Direct access, meaning whether a patient can see you without a referral, varies by state and is a separate question from authorization.⁵ For any specific patient, the plan is the only definitive answer.

Worth knowing that CMS does run prior authorization programs inside Original Medicare. Therapy isn’t in any of them. The standing list covers hospital outpatient department services, non-emergent ambulance, durable medical equipment, home health and inpatient rehabilitation facilities, which is a different setting from your outpatient clinic.⁶ CMS also launched a model called WISeR in January 2026 that applies prior authorization to three services in six states, and outpatient therapy is not one of them.⁷

What the front desk tracks

Two clocks run on every Advantage patient, and they don’t run together.

The authorization clock is visits and dates. The documentation clock is treatment days, because the PT owes a progress report at least every 10 of them, and a renewal request generally needs a current one attached. So the way an authorization actually fails isn’t running out of visits. It’s reaching the last approved visit on a day when the progress note isn’t written yet.

Here’s what to have in front of you for every patient on an auth:

• Plan type, confirmed from the card at intake rather than assumed from last time
• Visits approved, with the start and end date of the approval
• Visits used so far
• Visits remaining when the next progress note comes due
• Who sends the renewal, and how far ahead they send it

The fourth one is the number most trackers don’t carry, and it’s the one that tells you whether you’re fine or about to have a problem. Visits remaining is a count. Visits remaining measured against the next progress note is a warning.

None of this applies to your Original Medicare patients, which is its own quiet trap. A mixed caseload means two regimes running side by side, and treating an Advantage patient like an Original Medicare one shows up weeks later as a visit that doesn’t get paid.

The time this takes is real. Clinicians describe a day’s documentation running anywhere from half an hour to an hour depending on how much insurance paperwork and how many letters are in it, on a caseload of a dozen patients or more. The tracking itself is quick. It’s the rework when the tracking slips that costs the afternoon.

Where to check, and who to ask

Thresholds and rules change every year, so bookmark the sources rather than the numbers.

• CMS publishes the outpatient therapy rules and the KX modifier threshold. That figure updates annually, so take it from CMS on the day you need it.
• CMS’s prior authorization and pre-claim review list shows which services actually require prior authorization under Original Medicare, if you want to confirm it yourself.
• Your Medicare Administrative Contractor publishes local coverage determinations and billing articles that add regional detail to the national rule. CMS lists which one serves your state.
• The patient’s Advantage plan is the only authority on its own visit counts, date ranges and renewal process. No article can answer that for a specific patient.
• APTA tracks direct access by state, which is a separate question from authorization.

Save the authorization lines as snippets

The tracking above produces two messages, over and over. The status line, with visits approved and the date range. And the note to the treating PT that a progress note is needed before the next request goes in.

The free Physical Therapy Starter Kit names those two /auth and /pnauth. It holds 20 snippets covering cancellations, reminders, benefits and the authorization lines, and it installs in one click and edits like anything else you’ve written. Text Blaze runs in the browser, so the same shortcut works in your EMR, the payer portal, email and the tool you text patients from.

Nothing here answers a patient for you. The person at the desk still decides what to send and still has the conversation. A snippet saves them typing the same status line for the tenth time that day, and it means the answer reads the same whoever is on shift.

Install the free Physical Therapy Starter Kit