PT documentation gets denied more than any other rehab specialty. Here are the documentation requirements for 97110, 97140, 97530, the 8-minute rule, and how to keep payers happy.
Physical therapy has the highest documentation denial rate among rehabilitation specialties: 16% of PT claims are denied on first submission compared to 11% for occupational therapy and 9% for speech therapy (source: APTA Payment Policy Update, 2024). The reason isn't that PT documentation is inherently harder. It's that the rules are specific, the payers are aggressive, and the documentation must prove medical necessity at every visit.
This guide covers the documentation requirements that trip up PT practices most: timed codes, the 8-minute rule, plan of care elements, re-evaluation timelines, and payer-specific traps.
The 8-minute rule: how to get it right
The 8-minute rule determines how many units you can bill for timed CPT codes. A timed code requires at least 8 minutes of direct, one-on-one treatment to bill one unit. Here's the breakdown:
1 unit: 8 to 22 minutes of direct treatment
2 units: 23 to 37 minutes
3 units: 38 to 52 minutes
4 units: 53 to 67 minutes
The common mistake: rounding up. If you provide 21 minutes of therapeutic exercise (97110), that's 1 unit, not 2. Billing 2 units at 21 minutes is a denial. Your documentation must include the exact start and stop time for each timed service.
When billing multiple timed codes in the same session (e.g., 97110 and 97140), you add the total minutes across all timed codes and then distribute units. 18 minutes of 97110 + 15 minutes of 97140 = 33 total minutes = 4 units (distributed based on which service had more time).
Key CPT codes and what they require
97110 (Therapeutic Exercise): Exercises to develop strength, endurance, flexibility, or range of motion. Documentation must include: specific exercises performed, sets/reps/duration, patient response, and how it relates to functional goals. "Patient performed exercises" is not sufficient. "Patient performed 3 sets of 10 reps of supine straight leg raises, achieving 40 degrees hip flexion (up from 30 degrees last visit), with 3/10 pain" is.
97140 (Manual Therapy): Skilled hands-on techniques: joint mobilization, soft tissue mobilization, manual traction. Document: the specific technique, the body region, the grade of mobilization, and the patient's response. Payers deny manual therapy when the documentation doesn't distinguish it from massage (which is not covered by most plans).
97530 (Therapeutic Activities): Functional activities that use multiple body systems. Document: the specific activity (not just "therapeutic activities"), the functional goal it addresses, and how it differs from therapeutic exercise. The line between 97530 and 97110 is the most common audit trigger in PT.
97112 (Neuromuscular Re-education): Movement, balance, coordination, kinesthetic sense, posture. Document the specific deficit being addressed and the functional goal. This code is frequently denied when used as a substitute for 97110 without documenting the neurological component.
Plan of care requirements
Every PT patient must have a plan of care (POC) that is certified by the referring physician (or the PT in direct-access states). The POC must include:
Diagnosis and date of onset: The ICD-10 code and when the condition started. Use the most specific code available. M54.41 (lumbago with sciatica, left side) is better than M54.5 (low back pain).
Functional limitations: What the patient can't do. Not "limited ROM" but "unable to reach overhead to dress independently" or "cannot walk more than 100 feet without rest due to pain."
Goals with timeframes: Short-term (2-4 weeks) and long-term (discharge) goals that are measurable. "Improve strength" is not a goal. "Increase left hip flexion ROM from 30 to 60 degrees within 4 weeks" is.
Frequency and duration: "2x/week for 6 weeks" is standard. Any change to frequency or duration requires documentation of why.
Certification date: The POC must be certified within 30 days of the first visit. Recertification is required every 90 days for Medicare. Miss this deadline and all visits after the lapse are denied.
Re-evaluation requirements
Medicare requires a formal re-evaluation at least every 10 visits or 30 days, whichever comes first. The re-evaluation must document: current status vs. initial evaluation, progress toward goals, changes to the plan of care, and justification for continued treatment.
Payers use re-evaluations to determine whether continued therapy is medically necessary. A re-evaluation that shows no progress and no change to the plan is a red flag that triggers denial of subsequent visits.
How AI documentation helps PT practices
An AI Scribe trained on physical therapy documentation captures the treatment session verbally and generates a note that includes: specific exercises with sets/reps/duration, timed code minutes (start and stop), patient response and progress toward goals, and the appropriate CPT codes based on documented services.
The result: fewer denials from incomplete documentation, accurate 8-minute rule compliance, and therapists who spend time treating instead of typing.
Frequently asked questions
How many units can I bill for a 45-minute PT session?
It depends on how many minutes are spent on timed vs. untimed codes. If 40 minutes are spent on timed codes (e.g., 20 min 97110 + 20 min 97140), that's 5 total units under the 8-minute rule. If 5 minutes are untimed (evaluation, patient education), those don't count toward timed units.
What's the difference between 97110 and 97530?
97110 (therapeutic exercise) targets specific deficits: strength, ROM, endurance. 97530 (therapeutic activities) involves functional tasks that use multiple body systems. Reaching into a cabinet to practice overhead function is 97530. Shoulder flexion with a resistance band is 97110. The activity must be dynamic and functional to qualify as 97530.
How often do I need to recertify the plan of care?
Medicare requires recertification every 90 days. The recertification must include updated goals, current status, and justification for continuing treatment. Some commercial payers have shorter windows (60 days). Check payer-specific requirements.
The bottom line
PT documentation denials aren't random. They follow predictable patterns: 8-minute rule violations, missing plan of care elements, undocumented functional goals, and stale re-evaluations. Every one of these is preventable with the right documentation workflow and an EHR that understands PT-specific requirements.
See how Trustro handles PT documentation. Book a demo at /demo with physical therapy templates loaded.
Related reading
Read more: /blog/cpt-icd-10-coding-best-practices
Read more: /blog/ai-medical-coding-accuracy
See how this works in the product: /specialty/physical-therapy