Getting Paid for OT Under Medicare
Medicare Part B covers occupational therapy, but it does not cover it the way private insurers do. There is no clean claim form you just fill out and forget. The reimbursement path has specific requirements around certification, therapy thresholds, and documentation that, if handled incorrectly, will get your claim denied or delayed. I have seen clinics lose thousands because someone used the wrong modifier on a claim. To understand how the payment actually flows, you need to look at the eligibility piece first, then the billing mechanics, then the pitfalls. Part B is the relevant section here. Medicare Part A generally does not cover outpatient OT. If your patient is coming from a skilled nursing facility or inpatient hospital stay, Part A might apply, but most OT billing falls under Part B. Covered services include evaluation and re-evaluation, therapeutic interventions, and discharge planning. The OT must be providing services that are reasonable and necessary for diagnosing or treating an illness or injury. That sounds standard, but it matters because Medicare will question services that look like general wellness or maintenance. Custodial care is not covered. If the patient is just needing help with dressing because they have arthritis but no functional deficit being treated, the claim will likely be flagged.
The therapist needs to be enrolled in Medicare and must provide services under a physician's plan of care. The initial certification has to be completed by a doctor or eligible practitioner. The plan of care must be established, reviewed at least every 60 days, and recertified periodically. Skipping the recertification timeline is one of the most common reasons for audit findings. Here is the part that trips people up. The Medicare therapy threshold. In 2026, the combined therapy threshold is still $2,490 for PT and SLP services together and $2,490 for OT services. When a patient's expected total professional charges exceed that threshold in a calendar year, the payer requires a modifier. You use GZ, GP, or GX depending on whether you expect Medicare to deny, provide partial payment, or not cover the service at all. The modifier signals to Medicare that you anticipate the threshold being crossed and that you have documented medical necessity. I ran into a specific situation recently where a patient was near the OT threshold and we had been billing without modifiers because the patient had only received three sessions that month. By session six, the cumulative charges pushed past the threshold. The claim came back with a denial based on missing modifier application. What fixed it was going back and reviewing the original plan of care, pulling the accumulated billed amount, and resubmitting with the appropriate GZ modifier along with a covering letter that referenced the specific documentation supporting medical necessity. It added about two hours of administrative work for one claim, but it also forced us to tighten our tracking. We started using a running threshold tracker in our practice management system after that, and now we catch these cases before submission instead of after.
Documentation is where the actual payment risk lives. Medicare auditors do not pay attention to your subjective feeling that the treatment was appropriate. They look for objective measures. Standardized outcome instruments are your best defense. Things like the Functional Independence Measure, the Barthel Index, or the Upper Extremity Functional Score give you defensible data points. I recommend using at least one validated tool at evaluation, at key intervals, and at discharge. Without that, a clinical note that says "patient improved" is not going to survive a Random Medical Review. You also need to be careful with the time-based billing rules. Medicare does not allow you to bill multiple CPT codes for the same 15-minute unit if you are bundling them into a single block of time. If you spend 35 minutes on gait training and 20 minutes on manual lymphatic drainage in the same session, you bill the gait code for two units and the lymphatic drainage code for one unit, but you cannot double count the overlapping minutes. This is a frequent source of overbilling and clawbacks. There is a counter-intuitive thing about modifiers that most newcomers miss. The X modifier subdivisions (XE, XP, XS, XI) exist for a reason but they are more scrutiny triggers than protections. When you append an XS modifier to indicate separate practitioner, Medicare reviewers often pull those claims for additional review. If you can bill accurately without them, you generally will move through processing faster. Use them when they are actually required, not as a default habit.
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Another nuance: telehealth for OT under Medicare has expanded but still has gaps. As of the current rules, home health OT can be delivered via telehealth in many more situations than before, but certain settings like outpatient clinics have more restrictions. Check the CMS telehealth grid before you set up a remote session. Billing telehealth under the wrong place of service code will result in a denial that takes weeks to reverse. The reimbursement amounts themselves are determined by the Medicare Fee Schedule in your geographic region. The conversion factor changes annually. In 2026, the national baseline conversion factor is around $33.86, but local adjustments based on your BSA and urbanicity index will shift what you actually receive. A CPT like 97530 (therapeutic procedures) might pay one amount in your zone and significantly less in another. Always check the current year's fee schedule before setting your rates or telling patients what their coinsurance will be. Patient coinsurance is 20% of the Medicare-approved amount after the Part B deductible is met. The 2026 Part B deductible is $283. If the patient has not met their deductible, they owe the full approved amount until it is satisfied. Making sure your front desk verifies benefits and deductible status before the first visit saves you from chasing payments later. I have seen practices lose entire months of revenue because they assumed a patient's insurance was active without verifying the deductible status at intake.
If you are setting up Medicare billing for the first time, the practical steps are straightforward but tedious. Enroll through the CMS portal or use a reliable enrollment service. Get your NPI, confirm your enrollment status, verify that your tax ID is correctly linked, and then run test claims before accepting patients. Test claims will show you whether your rendering provider setup, place of service codes, and modifier configurations are working correctly. One hard limitation to accept: Medicare will audit you regardless of practice size. The Recovery Audit Contractor program does not discriminate. Large systems get audited and small solo practices get audited at similar rates relative to their claim volume. The only real protection is accurate documentation, correct coding, and ongoing staff education. Automation tools can help with threshold tracking and modifier suggestions, but they cannot replace a therapist who documents objective outcomes and a biller who knows when a claim needs additional support. For resources, CMS publishes the Medicare Claims Processing Manual and the Medicare Benefit Policy Manual directly on their website. Both are dense reads but they are the authoritative source. Your Medicare Administrative Contractor also provides local coverage determinations that may add additional requirements specific to your region. Those local policies can override general guidance, so always check whether your MAC has issued any recent bulletins on OT billing before you submit a batch of claims.
