PT billing has one of the highest denial rates in outpatient care — driven by timed vs. untimed code errors, missing KX modifiers, Medicare cap tracking failures, and functional limitation reporting lapses. We build the workflows that prevent them.
Common Billing Challenges
These are the billing failure points we see most often in physical therapy practices — and the ones our team resolves systematically from day one.
PT uses two categories: timed codes (97110, 97140) billed in 15-minute units and untimed codes (97012, 97018) billed once per session. The 8-minute rule governs unit billing for timed codes — billing wrong units is the #1 PT coding error and triggers automatic edits.
Medicare requires the KX modifier on claims when a patient has exceeded the therapy cap but medically necessary treatment continues. Without KX, all post-cap claims deny automatically — no appeal possible.
Medicare requires functional limitation severity codes (G-codes) at initial evaluation and every 10th visit. Missing G-codes cause claim denials. CMS has increased audit frequency for FLR compliance in 2026.
PT services billed under a general supervision model (not direct supervision) must meet specific documentation requirements. Incorrect supervision documentation for services performed by PTAs can trigger retroactive audits.
The 8-minute rule determines how many timed units to bill based on total timed treatment minutes. A 23-minute timed session = 1 unit; 38 minutes = 2 units. Manual calculation errors affect collection rate on every PT encounter.
A HEP (home exercise program) is required documentation for certain PT billing scenarios and payer audits. Missing or generic HEP notes increase audit risk and can cause claim recoupment.
Key Procedure Codes
Our coders hold specialty-specific credentials and train continuously on the codes that drive the most revenue — and the most denials — in physical therapy.
| CPT Code | Description | Common Issue |
|---|---|---|
| 97110 | Therapeutic exercises | 8-minute rule; units capped by payer |
| 97140 | Manual therapy techniques | Common modifier 59 requirement with 97110 |
| 97530 | Therapeutic activities | ADL focus; medical necessity documentation critical |
| 97012 | Mechanical traction | Untimed — once per session regardless of duration |
| 97035 | Ultrasound therapy | Untimed; frequency restrictions by payer |
| G8978/G8979 | Functional limitation reporting | Required by Medicare every 10 visits |
Why Rcmaxis
We're not a generalist billing service that added a specialty module. Our team is built around specialty-specific expertise.
Our billing system applies the 8-minute rule automatically across all timed PT codes — no manual calculation, no unit errors.
We track therapy cap use per beneficiary and automatically apply the KX modifier before the claim reaches the payer.
Functional limitation G-code requirements are tracked per episode of care and flagged before the 10th visit.
We monitor Medicare therapy cap use ($2,230 per discipline in 2026) and alert your practice before limits are reached.
We apply the correct modifier for services delivered by PTAs and document supervision appropriately under CMS 2026 guidelines.
We manage prior authorization for PT visits at all commercial payers — including session limit tracking per authorization period.
Straight answers to what practices usually ask before they switch.
Free revenue assessment for qualified practices. We audit your last 90 days of claims, identify every revenue leak, and show you a clear path to better collections — at no cost.