Most of us went to physical therapy school to treat patients, not to spend our lives mired in stacks of paperwork. But that’s what physical therapy billing can feel like: endless mountains of forms, claims, and invoices. As much as we malign it, though, billing accurately for our services is crucial to keeping our clinic doors open so we can continue to treat those patients.

Because most of us haven’t received formal training on how to properly bill for our services, we might be leaving money on the table without even realizing it. And we’re probably dealing with unnecessary headaches from denied claims, too. That’s why I created this guide to accurate PT billing. Here are some of the simplest and most effective ways you can up your rehab therapy billing game:

Submit clean claims.

Submitting clean claims is where it all starts, but it’s important to understand what that means. When I say “clean claims,” I mean insurance claim submissions that are free of errors and omissions. Submitting clean claims sounds easy in theory, but the reality is that there are plenty of ways to fudge the process, and that’s why properly training your staff is key.

So, make sure you train your front office staff to collect the following information at each patient’s first visit:

  • Name (with correct spelling)
  • Date of birth
  • Phone number and address
  • Social Security number
  • Insurance ID info (i.e., number, phone number from back of card, subscriber—which may or may not be the patient—and the subscriber’s date of birth)

Check—and recheck—everything.

It’s always a good idea to scan or photograph each patient’s driver’s license and insurance ID at the first visit. This allows you to easily recheck the claims paperwork prior to submission. In that vein, billing personnel should always double-check for the following paperwork issues prior to sending out claims:

  • Name misspellings
  • Incorrect demographic information
  • Missing data (e.g., ICD-10 codes, G codes, and modifiers)
  • Incorrect insurance information

Errors and omissions can lead to failures to collect copays and coinsurances, not to mention unexpected—and unpleasant—bills for your patients. A common mistake is omitting associated materials the first time you submit a claim, so make sure your billing team always includes additional authorization forms, prescriptions, and other documentation that might be required for timely payment.

Adhere to timely filing requirements.

Speaking of time: it often escapes the best of us, causing us to get behind on billing. A critical billing error many of us make is assuming that a late claim submission is still a valid claim submission—after all, you can usually deposit a check months after receipt—but some insurance carriers adhere to strict claim filing windows.

Because it’s vital to submit your claims within the allotted time frame, it’s imperative to have your staff on the same page. Each insurance carrier has its own rules about filing timelines, so make it a policy to train those responsible for submissions to stay up-to-date with the latest filing protocols for all of the carriers with which you’re credentialed.

Look closely at fixed-rate payer claims.

If you’re working with capped or fixed-rate payers, be aware that it’s easy to inadvertently underbill. Such payers will reimburse up to a certain capped amount, but unless you apply units to reflect the actual time you spent with the patient, you might not receive the full capped payment amount.

Double check patients’ coverage.

Just because a patient claims to have insurance coverage—and even has the card to prove it—that does not mean the coverage is active. The last thing you need is to be denied reimbursement after treating your patient for 13 visits.

To ensure that doesn’t happen, designate a staff member to check each patient’s insurance eligibility within 72 hours of the first interaction with that patient. If that’s not possible, at least verify eligibility before the patient’s first treatment. That way, if there are any copayments or deductibles the patient needs to know about (or if your patient requires prior authorization), you can get the ball rolling on paperwork—and be upfront about any patient-owed amounts.

In addition to having your staff verify all spelling, demographic, and insurance information at the  beginning of each new care episode, they should do the same at the end of each insurance provider’s calendar year. Yep, you guessed it: that means your staff must stay on top of all of your payers’ calendar cycles. That’s why taking the time to hire and train good support staff is so critical to your clinic’s success.

Use the right billing codes and modifiers.

It sometimes feels impossible to stay on top of all the coding and billing rules that apply to you, but it’s worth taking the extra time to ensure you’re using the right codes and modifiers for your treatments. Failing to do so is a bit like foregoing your company’s 401k matching plan: if you take the easy route and don’t bother signing up because you find it confusing, you’re likely leaving money on the table.

Avoid the ther-ex-for-all trap.

One simple rule of thumb is to avoid billing 97110 for everything that seems like therapeutic exercise. Think carefully, because many things you might want to bill as ther-ex might actually fall under therapeutic activities or gait training. It might just require a little more detail and clarification within your documentation. Plus, extreme overuse of the 97110 code could potentially be a red flag to auditors!

Use modifiers wisely.

Another thing to keep in mind is that different modifiers have different requirements for use. For example, therapy modifiers (e.g., GP, GO, and GN) are required to specify the type of therapy services—physical therapy, occupational therapy, and/or speech therapy—provided in treatment sessions. So if, for example, you are providing physical therapy services, then you would need to apply the PT modifier (GP) to every applicable CPT code on the claim. That helps payers categorize the services listed according to therapy discipline.

Modifier 59

The 59 modifier indicates that two linked services were performed separately and independently. In order to get reimbursed for both services, you must affix the modifier to one of the two services. If you’re already confused, you’re not alone. This handy reference is extremely helpful!

KX Modifier

The KX modifier is used when a patient exceeds the Medicare therapy threshold for a particular calendar year. This modifier must be affixed to every claim billed above this amount.


As much of a pain as it can be to create—and enforce—billing processes and protocols, you’ll be saner and more profitable because of it. After all, a denied claim typically doubles the time required to process payment, and double denials are even worse. If enough denied claims build up and affect your cash flow, your employees—and your patients—will suffer.

Did we miss anything? Let us know in the comments!

Meredith Castin, PT, DPT, is the founder of The Non-Clinical PT, a career development resource designed to help physical, occupational, and speech therapy professionals leverage their degrees in non-clinical ways. Meredith is also the co-founder of NewGradPhysicalTherapy and works as a freelance writer and editor for a variety of publications.