Occupational therapy (OT)

Occupational therapists evaluate a patient's functional capacity across physical, cognitive, and psychosocial domains, then design individualized intervention plans aimed at restoring participation in self-care, work, and leisure. In orthopedic practice, OT most commonly addresses hand and upper-extremity rehabilitation after fractures, tendon or ligament repairs, carpal tunnel release, total shoulder arthroplasty, and elbow reconstruction. Interventions include therapeutic exercise, neuromuscular re-education, manual therapy, splinting and orthotic fabrication, scar management, and training in adaptive techniques or assistive devices for ADLs and instrumental activities of daily living (IADLs).

OT evaluation is stratified by complexity. A low-complexity evaluation (CPT 97165) documents one to three performance deficits with a brief occupational profile, while a moderate-complexity evaluation (CPT 97166) expands to three to five deficits across cognitive, physical, and environmental factors. A high-complexity evaluation (CPT 97167) requires five or more documented performance deficits, often seen in patients with multilevel neurological involvement, complex post-surgical complications, or significant comorbidities. Re-evaluation (CPT 97168) is used when a formal reassessment triggers a change in the plan of care. All outpatient Medicare claims must carry the GO modifier to indicate services are delivered by or under the supervision of an occupational therapist.

Reimbursement for OT intervention services follows timed-code rules. High-volume orthopedic OT codes include therapeutic activity (CPT 97530), self-care and home management training (CPT 97535), neuromuscular re-education (CPT 97112), and community or work reintegration training (CPT 97537). When services are furnished in whole or in part—meaning 10% or more of timed minutes—by an occupational therapy assistant (OTA), the CO modifier is required under Medicare, and a 15% payment reduction applies to the OTA-delivered portion. Accurate time tracking and documentation of each timed unit are essential to pass claim edits and support medical necessity under CMS Local Coverage Determinations.

Miscoding OT complexity levels or omitting the GO or CO modifier on outpatient claims triggers automatic claim denial or post-payment audit under CMS billing articles A56566 and A53064. Undercoding high-complexity evaluations—such as defaulting to CPT 97166 when the note clearly documents five or more performance deficits—leaves reimbursement on the table (roughly a $20–25 difference between 97166 and 97167 at 2026 Medicare non-facility rates). Conversely, upcoding without explicit documentation of deficit count and modification degree constitutes a billing error with fraud-and-abuse exposure. For orthopedic practices that supervise OTs or OTAs in a therapy department, failure to apply the CO modifier for OTA-delivered minutes violates CMS requirements and can result in recoupment across an entire billing period.