Why occupational therapy billing needs its own approach
Fastora provides occupational therapy billing services for outpatient OT clinics, hand therapy practices and pediatric therapy groups. Occupational therapy medical billing looks similar to PT on the surface, since both use timed 15-minute codes, but the evaluation codes, discipline modifier and Medicare threshold are all distinct, and OT leans more heavily on pediatric and Medicaid payers with their own authorization rules.
OT practices treat hand injuries, stroke recovery, developmental delays and limits in daily living, and each patient group points to a different payer mix. Getting the claim right means matching the code, the modifier and the payer's rule for that specific population, then tracking visits so the authorization or benefit does not run out mid-episode.
Our OT billing services cover eligibility and benefits, authorizations, charge review, our Advanced Pre-Submission Claim Review before electronic submission, payment posting, denials and AR follow-up. Every claim is handled by certified medical billing and coding professionals.
OT evaluation codes 97165, 97166 and 97167
Occupational therapy evaluations are billed at one of three complexity levels. The level reflects the depth of the occupational profile and history, the number of performance deficits identified, and the complexity of clinical decision-making. Evaluations are untimed and billed once per session.
| Code | Descriptor (summary) | Billing unit |
|---|---|---|
| 97165 | Occupational therapy evaluation, low complexity | Untimed |
| 97166 | Occupational therapy evaluation, moderate complexity | Untimed |
| 97167 | Occupational therapy evaluation, high complexity | Untimed |
| 97168 | Re-evaluation of occupational therapy established plan of care | Untimed |
A re-evaluation is not a routine progress check. Medicare generally expects new clinical findings, a significant change in function or a lack of expected progress before 97168 is billed, and many commercial payers follow the same logic. Some plans also cap how many re-evaluations they pay in a year, so we check the policy before the visit is coded.
Occupational therapy CPT codes for treatment
Most OT treatment codes are timed. For Medicare, units follow the 8-minute rule applied to total timed minutes for the visit; some commercial payers count each code separately, so a service needs 8 minutes on its own to earn a unit. The note should name the functional task being trained, not only the exercise.
| Code | Descriptor (summary) | Billing unit |
|---|---|---|
| 97535 | Self-care/home management training (eg, activities of daily living, compensatory training, meal preparation, safety procedures, use of assistive devices or adaptive equipment), direct one-on-one contact | Each 15 minutes |
| 97530 | Therapeutic activities, direct one-on-one patient contact, using dynamic activities to improve functional performance | Each 15 minutes |
| 97110 | Therapeutic exercises to develop strength and endurance, range of motion and flexibility | Each 15 minutes |
| 97112 | Neuromuscular reeducation of movement, balance, coordination, kinesthetic sense, posture and/or proprioception | Each 15 minutes |
Documenting the 97535 CPT code
Self-care training is one of the codes most closely tied to OT. A note that supports 97535 names the daily task (dressing, bathing, meal preparation, use of adaptive equipment), the cueing or assistance level, and the minutes of direct one-on-one training. A note that lists only exercises performed is more likely to be recoded or denied on review.
Because several of these codes are shared with physical therapy, the discipline modifier and the plan of care decide which benefit the service counts against. Clinics that run both disciplines can compare our approach to PT claims.
Occupational therapy billing guidelines for Medicare: the GO modifier and OT threshold
Medicare requires the GO modifier on services delivered under an occupational therapy plan of care. Many commercial and Medicaid plans use the same modifier, and a missing or mismatched discipline modifier is a frequent cause of rejected lines. The same CPT code billed by a PT carries GP instead, which is why the modifier, not the code, tells the payer which discipline delivered the care.
Medicare sets an annual per-beneficiary threshold for occupational therapy that is separate from the combined threshold for physical therapy and speech-language pathology. CMS publishes the amounts each year on its therapy services page. Once a patient's OT charges pass the OT threshold, lines need the KX modifier to attest medical necessity, and a higher, separate amount can trigger targeted medical review.
For 2026, the separate occupational therapy threshold is $2,480 per beneficiary (CMS, 2026 Annual Update of Per-Beneficiary Threshold Amounts). CMS revises the amount each year, so verify the current figure before the calendar year turns.
Since the OT threshold is tracked on its own, a patient who used PT earlier in the year may still be well under it for OT. We track the two separately instead of treating therapy as one pool. Medicare's certified plan of care, recertification and progress report rules apply to OT just as they do to PT.
OTAs, supervision and the CO modifier
For Medicare, services furnished in whole or in part by an occupational therapy assistant carry the CO modifier, reported together with GO, and are paid at a reduced rate. CMS applies a de minimis standard, so CO is required when the assistant's minutes exceed 10 percent of the service.
OTA services are billed under the supervising occupational therapist. Supervision rules depend on the setting, the payer and the state practice act, so we confirm them before assistant visits are scheduled.
Pediatric occupational therapy billing and Medicaid
Pediatric OT is often paid by Medicaid or CHIP. Under Medicaid's Early and Periodic Screening, Diagnostic and Treatment (EPSDT) benefit, children and young people under 21 are entitled to medically necessary services, but each state and managed care plan sets its own authorization steps and visit rules.
Commercial plans may separate rehabilitative benefits (restoring lost function) from habilitative benefits (building skills never acquired), each with its own visit count. Some also limit coverage for certain developmental diagnoses. We verify which benefit applies before the evaluation, so the family knows their share early.
- Children with both commercial coverage and Medicaid: the commercial plan is billed first, then Medicaid as secondary once the primary pays or denies.
- Sensory and fine-motor goals: documentation ties each goal to a functional skill at home or school, which payers look for on review.
- Children who also receive applied behavior analysis: OT and ABA are separate benefits, and our ABA billing page covers that side.
Authorizations and visit limits for OT
Many Medicaid plans and commercial insurers require authorization for OT after the evaluation, and some share one visit pool across PT, OT and speech therapy. We submit authorization requests, record approved visits and date ranges, and flag cases before the authorization or benefit runs out so the therapist can send updated goals in time.
When a child is seen twice a week, a 12-visit authorization lasts about six weeks, not the three months the date range may suggest. We compare approved visits against the schedule, not just the end date.
OT denials and AR follow-up
Common OT denials include a missing GO or KX modifier, units that do not match documented minutes, visits past the authorized count, evaluations billed at a level the note does not support, and habilitative services billed under a rehabilitative benefit. Each is logged by reason and payer through our denial management service so repeat errors are fixed upstream.
Open claims are worked by payer and age, with secondary claims to Medicaid released once the primary pays. Appeals include the plan of care, functional measures and progress notes.
Occupational therapy credentialing
Each OT needs an NPI, a state license and enrollment with each payer, including Medicaid managed care plans for pediatric practices. OTs in private practice enroll with Medicare individually and reassign benefits to the group. We run each application through our tracked credentialing and enrollment process, from document collection and CAQH setup to final approval, and flag new hires so they are not scheduled with a payer before their effective date.
Working with Fastora
Our Virtual Assistant team verifies benefits, visit limits and authorization before care starts and collects copays upfront. Scriber support records documentation in your EHR in real time. Certified billers apply evaluation tiers, timed units and modifiers, then handle claims, payment posting, denials and AR.
We work inside your existing EHR/PM system with no hidden setup fees, and each practice has a dedicated account contact and monthly performance reporting. Pricing is quoted after the assessment, as explained on our pricing page. Groups that also offer counseling for children and families can review our behavioral health billing.
Code-level detail for evaluations, 97530 and 97535, and GO modifier use is in our guide to occupational therapy CPT codes.