Occupational Therapy Pays for Function, Not Repetitions
Occupational therapy is the discipline most often billed under the wrong code. Self-care training, wheelchair management and functional activity each have their own timed code, and when a session is billed as generic therapeutic exercise the practice is paid less than the work is worth and describes a service it did not perform. Add a separate KX threshold that nobody tracks and assistant modifiers that decide 15 percent of the payment, and the revenue cycle has three places to leak before a payer looks at anything.
Why Occupational Therapy Claims Get Cut
OT denials cluster in three places: the code chosen, the threshold nobody tracks, and a note that describes exercise rather than occupational performance.
Self-care and wheelchair sessions are billed as therapeutic exercise
97110 covers therapeutic exercise to develop strength, endurance, range of motion and flexibility. It does not describe training a patient to dress with one hand, which is 97535 self-care and home management training, or assessing, fitting and training a patient in a wheelchair or mobility device, which is 97542 wheelchair management. All three are timed 15 minute codes, so billing the work under 97110 pays less than the service is worth and leaves a reviewer holding a note that does not match the code.
Hot packs and unattended stimulation are billed as payable lines
97010 application of hot or cold packs is always bundled into the therapy service and is never separately payable. 97014 unattended electrical stimulation is bundled with other therapy services furnished on the same date. Only constant attendance modalities such as 97032 attended electrical stimulation and 97035 ultrasound are separately payable timed codes. Billing the bundled ones adds no revenue, and a pattern of it is exactly the kind of charge detail a medical reviewer pulls first. The CY 2026 fee schedule sharpened the point by applying an efficiency adjustment to non-time-based services such as evaluation codes and supervised modalities while leaving timed treatment codes largely untouched.
Group therapy is billed by the number of patients
97150 therapeutic procedures in a group of 2 or more individuals is an untimed code, reported at one unit per patient per date of service for the time that patient spends in the group. Time in a group does not count toward that patient's timed units for individual services, and a patient pulled out of the group for one-on-one work has to have that time documented and billed as the individual code it was. Treating group minutes as timed units inflates the claim in a way that is simple to check.
The OT threshold is treated as part of the general therapy bucket
Occupational therapy carries its own $2,480 KX threshold for CY 2026, separate from the amount that physical therapy and speech-language pathology share. Practices that track one combined figure either apply KX to OT lines too early or miss it entirely when OT crosses the threshold on its own. Claims above the OT threshold without the KX modifier are denied, and past $3,000 in the category they become eligible for targeted medical review.
OTA lines carry the wrong modifier
When an occupational therapy assistant furnishes a service in whole or in part, the line carries the CO modifier with GO and is paid at 85 percent of the fee schedule. The standard is more than 10 percent of the total time on that service, and the final unit in a multi unit session stays unmodified when the OT alone furnished 8 minutes or more of it. A missing CO brings a payment reduction after the fact, and CO applied to minutes the OT delivered cuts payment the practice earned. Neither error shows up in a monthly report that only looks at charges and collections.
The note proves exercise rather than occupational performance
Medical necessity for OT rests on a functional deficit in the tasks that make up a person's day: bathing, dressing, feeding, cooking, work tasks, home safety and community access. A note that reports sets, repetitions and tolerance without the functional goal, the level of assistance required and the skilled reasoning behind the intervention supports a unit count and nothing else. Timed units with no demonstrated skill behind them are the claim a payer can reduce to zero without disputing the time.
Five Stages From Code Audit to Clean Claims
One method applied to every date of service: the code has to describe the work, the note has to prove the skill, and the threshold has to be tracked before the claim goes out.
Audit code selection against the notes
We take 30 to 60 days of OT treatment notes and the matching charge detail, then rebuild each visit: which timed code the work actually describes, the total timed minutes, the units those minutes support, and the untimed services. Downcoded sessions such as ADL training billed as 97110 are listed with the dollars attached to the difference.
Repair the certification and documentation record
Every active plan of care is checked for the certifying signature and date, the 30 day certification window, the 14 day verbal order rule and the 90 day recertification cycle. Then the functional documentation gets a standard: the task, the level of assistance, the progress toward the goal and the clinical reasoning that makes the intervention skilled work.
Rebuild the billing rules in your system
Charge capture gets a unit calculator on total timed minutes, ADL and wheelchair prompts that route the clinician to 97535 or 97542, 97010 and 97014 removed from payable claim lines, and modifier logic for GO, KX, CO and 59 or XS where two codes touch the same region. The rules live in the system, not in one biller's memory.
Work the denials by remittance reason
Denials are triaged by remittance code rather than by age. Unit and bundling denials go back out with the calculation and the note attached. Medical necessity denials get a clinical appeal built on the plan of care, the progress reports and the functional measures. Timely filing disputes go out with the clearinghouse acknowledgement as proof of submission.
Track the OT threshold and the assistant mix
Per beneficiary OT spend is watched against the $2,480 threshold so KX lands on documented lines before submission, the share of each service furnished by an OTA is reported so CO is applied where it belongs, and you receive monthly reporting on units per visit, code mix, denial reasons and dollars recovered.
The Work Inside Occupational Therapy Billing
Six workstreams that keep the code, the note and the payment aligned on every OT claim.
OT coding and code selection
97165 to 97168 evaluations, 97110, 97112, 97140, 97530, 97535 self-care training and 97542 wheelchair management selected to match the work documented.
Timed unit calculation
Units derived from total timed minutes on every date of service, with group therapy and evaluations reported at one unit and time on untimed services excluded from the timed total.
Plan of care and certification tracking
Signature and date verification inside the 30 day window, verbal order follow-up, 90 day recertification alerts and a live list of plans drifting toward a lapse.
OT threshold and KX management
Spend tracked against the separate $2,480 OT threshold, with medical necessity packets assembled before the line that crosses it is submitted.
OTA modifier and supervision compliance
CO with GO applied against the 10 percent standard, the 15 percent reduction reconciled on every affected line, and the assistant mix reported monthly.
Denial, appeal and reporting work
Unit, bundling, medical necessity and timely filing denials handled by reason, with monthly reporting on code mix, units per visit, days in A/R and recovery.
What Changes When the Code Matches the Work
Same therapists, same patients, same payers. What changes is that an ADL session is billed as an ADL session and a wheelchair session as wheelchair management.
| What changes | Without a process | With MedFactor |
|---|---|---|
| ADL and self-care training | Billed as 97110 therapeutic exercise | Billed as 97535 with the functional goal documented |
| Wheelchair and mobility device work | Buried in a therapeutic activity unit | Billed as 97542 with the fitting and training recorded |
| Hot packs and unattended stimulation | Billed as separate payable modalities | Left off the claim as bundled services |
| Group therapy | Billed in timed units per patient | One unit per patient, counted outside the timed total |
| The OT threshold | Merged with the PT figure or ignored | Tracked on its own $2,480 account with KX applied correctly |
| Assistant furnished minutes | CO applied by memory | CO decided by the time standard and reconciled at 85 percent |
Occupational Therapy Billing Questions Answered
What practice owners and billing managers ask about OT codes, thresholds and assistant modifiers.
All four are timed 15 minute codes and they describe different work. 97110 is therapeutic exercise to develop strength, endurance, range of motion and flexibility. 97530 is therapeutic activities, dynamic one-on-one tasks used to improve functional performance. 97535 is self-care and home management training, the work of teaching a patient to perform activities of daily living and instrumental tasks. 97542 is wheelchair management, which covers assessment, fitting and training in the patient's mobility device. A dressing retraining session is 97535 work even when it includes strengthening as a component, and the note should say so.
No. Occupational therapy has a separate KX threshold, $2,480 for CY 2026, while physical therapy and speech-language pathology share a single combined threshold of the same amount. That means a heavy PT year does not use up OT headroom and an OT episode does not consume the PT bucket. The KX modifier goes on the OT lines once OT incurred expenses pass the OT threshold, and only where the documentation supports medical necessity. Past $3,000 in a category, claims become eligible for targeted medical review, an amount that stays fixed through 2028.
97010 application of hot or cold packs is always bundled into the therapy service and carries no separate payment, so a charge line for it earns nothing and draws attention. 97014 unattended electrical stimulation is bundled when furnished with other therapy services on the same date. Constant attendance modalities are payable timed codes, so 97032 attended electrical stimulation and 97035 ultrasound can be billed in 15 minute units when the therapist is in constant attendance and the minutes are documented.
97150 is untimed. Report one unit per patient per date of service for the time that patient spends in the group, and only when the group has 2 or more individuals. The minutes a patient spends in group do not count toward that patient's timed units for individual services on the same day, and any individual treatment time has to be documented separately and billed with its own code. Billing group time in 15 minute units or billing both a group unit and the same minutes as an individual service is the error to avoid.
The CO modifier is required when an OTA furnishes a service in whole or in part, meaning the assistant provided more than 10 percent of the total time for that service, and it is reported together with the GO therapy modifier. Those lines are paid at 85 percent of the fee schedule, a 15 percent reduction that has applied since CY 2022. A unit the OT furnished alone stays unmodified, including the final unit in a multi unit session where the OT contributed 8 minutes or more. We reconcile assistant minutes against the modifiers on every claim so the reduction is neither missed nor over-applied.
Use 97165, 97166 or 97167 for the initial evaluation and select by complexity: low, moderate or high, judged on the patient's presentation, the clinical decision making required and the plan developed. 97168 is the re-evaluation of an established plan of care. All four are untimed, so the unit field is 1, and the evaluation is incorporated into the plan of care rather than billed as treatment. Choosing a level the documentation cannot defend is a straightforward overpayment finding.
Two changes matter operationally. The CY 2026 therapy code list added three remote therapeutic monitoring codes, 98979 for the first 10 minutes of treatment management in a calendar month, and 98984 and 98985 for device supply over 2 to 15 days of a 30 day period, and revised 98976 and 98977 to describe 16 to 30 days in a 30 day period. All are designated sometimes therapy, so RTM furnished by a therapist under a therapy plan of care carries GP, GO or GN according to the discipline, and CO where an assistant furnishes the service in whole or in part.
CMS also applied an efficiency adjustment to non-time-based services, which includes evaluation codes and supervised modalities, while leaving timed treatment codes largely exempt. Verify each code against the current year fee schedule before submission.
You send 30 to 60 days of treatment notes, the charge detail from the same period and your current fee schedule. We rebuild the units, check whether each code describes the work in the note, verify certification dates and assistant modifiers, and report the dollars recoverable on claims already submitted plus the correction value per month going forward. The review is free, and the findings are yours whether or not you engage us.
Related specialties we bill for
The same code-level precision applies across the practice spectrum. See how we bill these related areas.
Sources and further reading
The rules these pages describe are published. Check them against the primary sources:
- CMS Physician Fee Schedule, which covers the published rates and payment rules behind most of the codes these pages discuss.
- CMS Physician Self-Referral (Stark Law), which covers the rules governing referrals between a practice and its own ancillary services.
- AAPC, which covers the coding and billing standards body whose credentialing most billers hold.
- HHS Office of Inspector General, which covers enforcement guidance on billing compliance and the areas it targets.
Find out which OT codes you are leaving money in
Send us a month of OT treatment notes with the matching charge detail. We will show you where ADL, wheelchair and functional work was billed as something cheaper, what the threshold position looks like, and what the correction is worth per month.