Physical therapy coding requires time-based procedure codes, functional outcome documentation, and therapy cap awareness. This page covers the top ICD-10-CM diagnosis codes and CPT therapy procedure codes used by physical therapists and physical therapy practices across the United States.
FY 2026 ICD-10-CM (CMS) · CPT codes updated annually · All codes verified billable · Last verified: June 2026
Therapeutic exercises to develop strength, endurance, range of motion and flexibility; each 15 minutes
~$36.20
-59, -GP
97530
Therapeutic activities, direct (one-on-one) patient contact; each 15 minutes
~$40.35
-59, -GP
97012
Application of a modality; traction, mechanical
~$23.15
-59, -GP
97014
Application of a modality; electrical stimulation (unattended)
~$10.40
-59, -GP
97035
Application of a modality; ultrasound, each 15 minutes
~$20.75
-59, -GP
97116
Therapeutic procedure; gait training (includes stair climbing), each 15 minutes
~$38.50
-59, -GP
97010
Application of a modality; hot or cold packs
~$N/A
-59, -GP (facility only)
97018
Application of a modality; paraffin bath
~$N/A
-59, -GP (facility only)
97022
Application of a modality; whirlpool
~$N/A
-59, -GP (facility only)
97024
Application of a modality; diathermy (e.g., microwave)
~$N/A
-59, -GP (facility only)
97026
Application of a modality; infrared
~$N/A
-59, -GP (facility only)
97032
Application of a modality; electrical stimulation (manual), each 15 minutes
~$29.80
-59, -GP
97033
Application of a modality; iontophoresis, each 15 minutes
~$33.45
-59, -GP
97034
Application of a modality; contrast baths, each 15 minutes
~$N/A
-59, -GP (facility only)
97150
Therapeutic procedure(s), group (2 or more individuals)
~$19.65
-59, -GO, -GP
97530-GP
Therapeutic activities with GP modifier (physical therapy plan)
~$40.35
-GP required
97542
Wheelchair management training, each 15 minutes
~$37.10
-59, -GP
*Approximate 2025 CMS national non-facility rate. Rates vary by geography, setting, and payer contract. Refer to the CMS Physician Fee Schedule for official rates.
Top Denial Reasons for Physiotherapy Claims
⚠
Medical Necessity Not Documented
Payers require objective functional measures (ROM, MMT scores, pain scale) and clearly documented skilled care rationale in each therapy note. Ensure the plan of care specifies measurable short- and long-term goals tied to the patient’s functional deficits.
⚠
Missing or Incorrect Therapy Discipline Modifier
Medicare requires -GP (physical therapy), -GO (occupational therapy), or -GN (speech-language pathology) modifiers on all therapy claims; omitting or using the wrong modifier results in automatic denial. Verify the correct discipline modifier appears on every therapy-timed code line item.
⚠
Therapy Threshold Exceeded Without KX Modifier
Once a Medicare beneficiary’s therapy charges exceed the annual threshold (~,230 for PT/SLP combined in 2025), the -KX modifier must be appended to certify medical necessity exceptions; missing -KX triggers automatic system denial. Track cumulative therapy spend per patient and apply -KX proactively once the threshold is crossed.
⚠
Diagnosis Not Supporting the Procedure (LCD/NCD Mismatch)
Local Coverage Determinations (LCDs) for physiotherapy modalities (e.g., electrical stimulation, ultrasound) require specific ICD-10-CM diagnosis codes from an approved list; billing a procedure with a non-covered diagnosis results in denial. Cross-reference the applicable LCD before claim submission and ensure the primary diagnosis is listed first on the claim form.
Physiotherapy Billing & Coding Tips
Therapeutic exercise (97110) and therapeutic activities (97530) are time-based — bill in 15-minute units and document the total time spent in timed vs. untimed services.
Always document functional limitations and measurable goals to support medical necessity for ongoing PT beyond 8–12 visits.
Use KX modifier when therapy services exceed the annual Medicare cap but are medically necessary — document this in the plan of care.
97012 (mechanical traction) and 97014 (electrical stimulation) are constant attendance codes only; supervised (non-attended) versions may not be separately billed in all payer contracts.
97110 (Therapeutic exercise) and 97530 (Therapeutic activities) are the most frequently billed PT codes. Both are time-based: bill one unit per 15 minutes of direct one-on-one treatment. Document start/stop times for each timed code.
What is the 8-minute rule?
Under Medicare, a single 15-minute timed unit requires at least 8 minutes of treatment. For multiple timed units, total treatment time determines the number of billable units — use the total-time method (not the individual-service method) per CMS policy.
When is the KX modifier required?
The KX modifier is required on PT claims after the annual therapy cap is exceeded (typically ~,230 for PT/SLP combined under Medicare). It attests that services are medically necessary and documented in the plan of care.
What ICD-10 code is used for post-op PT after knee replacement?
Z47.1 (Aftercare following joint replacement surgery) is the primary code for post-surgical PT. Add the condition treated (M17.11) as a secondary code. Z47.1 covers PT, OT, and wound care following joint replacement.
How does OmniMD support physical therapy billing?
OmniMD’s Physical Therapy EHR module includes timed code calculators, therapy cap tracking with KX modifier alerts, functional outcome measure tools (FOTO, OPTIMAL), and progress note templates aligned with Medicare documentation requirements.
Streamline Your Physiotherapy Practice with OmniMD
Purpose-built EHR, billing, and practice management for Physiotherapy practices.
