Medicare PT Billing: What You Need to Know About Physical Therapy Billing Rules

When it comes to Medicare PT billing, the process of submitting claims for physical therapy services covered by Medicare. Also known as Medicare therapy billing, it’s the system that determines whether a physical therapist gets paid for treating seniors and eligible beneficiaries. This isn’t just paperwork—it’s the bridge between care and payment. If the billing is wrong, the therapist doesn’t get paid, and the patient might be stuck with unexpected bills.

Physical therapy under Medicare isn’t free, but it’s covered under Part B when it’s medically necessary. That means physical therapy, hands-on treatment to improve mobility, reduce pain, or recover from injury or surgery. Also known as PT, it includes exercises, manual therapy, and equipment training. But here’s the catch: Medicare has strict rules on how often you can bill, what codes to use, and when therapy is considered "maintenance" versus "rehabilitative." Many therapists get claims denied because they mix up the modifiers or hit the therapy cap without using the right exceptions.

Then there’s therapy cap, the annual spending limit Medicare sets on outpatient therapy services. Also known as therapy expenditure limit, it was $2,330 in 2024 for physical therapy, speech therapy, and occupational therapy combined. But that cap isn’t a hard stop. If your doctor certifies that your therapy is medically necessary beyond that amount, you can keep going—no extra paperwork needed from the patient. This is where most people get tripped up. They assume the cap cuts off care. It doesn’t. It just triggers a review.

Another big piece is KX modifier, the code therapists add to claims when services go over the therapy cap and are still medically necessary. Also known as therapy exception modifier, it tells Medicare: "This isn’t optional—it’s essential." Without it, claims get auto-rejected, even if the patient needs the treatment. It’s not a loophole. It’s a requirement. And if you’re a patient, you should know your therapist is supposed to explain this to you before you hit the cap.

Medicare doesn’t pay for every session. They only cover services that show progress. If you’ve been doing the same exercises for months with no improvement, Medicare may say it’s maintenance care—and deny future claims. That’s why therapists track functional goals: walking distance, stair climbs, balance scores. Without those numbers, they can’t prove the therapy is working.

And don’t forget the difference between direct and indirect billing. If you’re seeing a therapist in a clinic, they bill Medicare directly. But if you’re getting therapy at home through a home health agency, that’s a different billing system entirely. Mixing them up causes delays, confusion, and sometimes, out-of-pocket costs you didn’t expect.

What you’ll find in the posts below isn’t a textbook on billing codes. It’s real talk from people who’ve been there—the therapists who’ve fought denials, the patients who got stuck with bills they didn’t understand, and the clinics that cracked the code on getting paid without burning out. You’ll learn how to spot red flags in your own billing statements, what to ask your therapist before starting care, and how to avoid the most common mistakes that cost time and money. This isn’t about memorizing CMS guidelines. It’s about knowing your rights and making sure you get the care you’re entitled to—without the headache.