Physical Therapy Medicare Compliance: Plan of Care + Documentation Rules

Outpatient physical therapy services billed to Medicare Part B are governed by 42 CFR § 410.59 and CMS Pub. 100-02 Chapter 15 § 220. Compliance turns on a certified plan of care, accurate timed-code documentation, the KX modifier when therapy charges exceed the annual threshold, and CQ/CO modifiers when a PTA or OTA provides 10 percent or more of the service.

What CMS actually requires for outpatient PT

Medicare Part B covers outpatient physical therapy services under section 1861(p) of the Social Security Act, implemented at 42 CFR § 410.59 for private practice and 42 CFR § 410.60 for CORF and outpatient hospital settings. The conditions for coverage include direct PT supervision for services billed under the PT's NPI, a written plan of care certified by a physician or NPP, services that are reasonable and necessary, and services that meet the level of care and skilled-therapy expectations in CMS Pub. 100-02 Chapter 15 § 220.

The plan of care must include the diagnoses, long-term treatment goals, type/amount/duration/frequency of services, and signature of the PT establishing the plan. The physician or non-physician practitioner must certify the plan within 30 days of the first treatment day under 42 CFR § 410.61(c). Recertification is required at least every 90 days from the initial certification.

Documentation must follow the 8-minute rule for timed CPT codes. CPT codes that bill in 15-minute increments (97110 therapeutic exercise, 97140 manual therapy, 97530 therapeutic activities, and others) require at least 8 minutes of direct one-on-one time to bill one unit, with the unit count following the Medicare 8-minute rule table in CMS Pub. 100-04 Chapter 5 § 20.2. Time spent on documentation, assessment unrelated to a timed code, and unattended modalities is not counted.

The KX modifier is appended when annual allowed charges for combined PT and speech-language pathology services exceed the threshold ($2,480 for 2026, separate threshold for OT at $2,480). Appending the KX modifier is the provider's attestation that the services above the threshold are medically necessary and supported in the medical record. Above $3,000 the claims become eligible for targeted medical review. For 2025 and 2026 the targeted-medical-review threshold remains at $3,000 absent further congressional adjustment.

The CQ modifier (PTA) and CO modifier (OTA) are required since January 2022 on any service line where a PT assistant or OT assistant provided at least 10 percent of the therapy minutes for that service. Calculation is per service, not per visit. Improper modifier application is one of the most common documentation findings.

The documents you must maintain

The PT Medicare compliance binder should hold:

• Certified plan of care for every Medicare patient, with physician/NPP signature, date, and the 30-day certification verified
• Recertification log tracking the 90-day recertification cycle for every active patient
• Timed-code documentation including start and stop times, direct one-on-one minutes for each timed code, and the 8-minute rule calculation
• CQ/CO modifier tracking showing PTA/OTA minutes per service line and the 10 percent threshold determination
• KX modifier tracking showing cumulative annual allowed charges per patient against the threshold
• Medical necessity narrative for every service above the targeted-medical-review threshold and for any service that might appear to exceed typical course-of-care expectations
• Supervision documentation for services provided in private practice with PT direct supervision required
• Treatment notes documenting skilled intervention, response, and progression toward plan-of-care goals — not just exercise lists
• Discharge summary documenting goals met or not met and reason for discharge
• MIPS / Quality Payment Program participation records if MIPS-eligible, including measure data submitted

The audit failure pattern: notes that document exercises performed but not the skilled component (cueing, manual contact, progression, modification) that justifies billing the therapeutic exercise CPT code instead of unskilled exercise.

How TPE and RAC audits actually work for PT

Targeted Probe and Educate (TPE) audits target providers whose billing patterns deviate from CMS-published expectations or from peer norms. The MAC pulls a probe of typically 20-40 claims. The provider has 45 days to respond. After the probe, the MAC scores the claims; a pass rate below approximately 85 percent advances to a second probe with one-on-one education between rounds. Three rounds of failed probes can result in extrapolated overpayment determination and referral to a UPIC or RAC.

What PT practices most often miss is that the TPE feedback letter between rounds is the binder gold. The feedback identifies specific documentation patterns the MAC flagged — typically inadequate skilled-care documentation, missing certifications, mis-billed timed codes, or KX modifier overuse. The remediation plan needs to address each finding line by line. Going into round 2 without changing the documentation pattern means failing round 2.

RAC (Recovery Audit Contractor) audits sample claims post-payment. PT-specific RAC topics published in recent years include excessive units per session, units billed without supporting timed-code documentation, services billed without a certified plan of care, and services billed with the KX modifier without supporting medical necessity. RAC audits use statistical sampling and extrapolation; an extrapolated finding can multiply a sample-level overpayment by 50 or more.

UPIC (Unified Program Integrity Contractor) audits are heavier and may include site visits, interviews, and beneficiary contact. UPIC referrals often originate from FBI/HHS-OIG joint operations or whistleblower tips. Treat any UPIC letter as a litigation event from the moment received.

Common gaps unique to PT practice

In PT Medicare audits we have responded to, the patterns are consistent:

• Plan of care not certified within 30 days — physician signature undated or dated outside the window. Without timely certification, the entire course of care is non-covered.
• Treatment notes that document the exercise without the skilled component — "patient performed 3 sets of 10 squats" is not skilled documentation. "PT cued patient for proper hip-hinge mechanics, manually corrected knee valgus during sets 2 and 3, progressed from bodyweight to 10-lb dumbbells with goal of pain-free single-leg stance" is.
• CQ/CO modifier omitted when PTA provided more than 10 percent — practices report PTA minutes correctly internally but fail to translate to the modifier on the claim.
• 8-minute rule miscalculation when multiple timed codes performed in one session — the rule applies to total timed-code minutes, not minutes per code. Misapplication produces extra units or missing units.
• Re-evaluation billed without the required change in status — CPT 97164 requires a significant change in condition or treatment direction, not routine reassessment.
• KX modifier appended to every claim once threshold exceeded — without documented medical necessity supporting each instance.
• Group therapy (97150) and one-on-one minutes mixed in documentation — 97150 is untimed and cannot be billed simultaneously with one-on-one timed codes for the same minutes.

Maintenance cadence

• Daily: timed-code start/stop times and skilled-care narrative for every treatment note
• Weekly: internal audit of 1-2 charts per provider for documentation-to-code fit
• Monthly: KX modifier tracker review; CQ/CO modifier reconciliation; review of plan-of-care certification status across the active caseload
• Quarterly: internal coding audit sample of 10+ claims per provider with findings documented and remediated
• Annually: full plan-of-care template review against current CMS guidance; therapy-cap threshold update at January; MIPS measure selection for the new performance year; CPT and ICD-10 code updates; staff documentation training

State preemption: where state law adds to Medicare

California — Business and Professions Code § 2620 et seq. (Physical Therapy Practice Act) and 16 CCR § 1399 govern scope of practice. California also requires PTs to complete fall-prevention continuing education and has stricter direct-access rules than several other states.

Texas — Texas Occupations Code Chapter 453 and 22 TAC § 322 govern PT practice. Texas Medicaid additionally requires authorization for therapy beyond a certain visit count regardless of Medicare rules.

New York — New York Education Law Article 136 governs PT practice. New York Workers' Compensation Board imposes separate documentation and authorization rules for any PT billed under workers' compensation that exceed Medicare's plan-of-care requirements.

Florida — Florida Statute Chapter 486 and Florida Administrative Code 64B17 govern PT practice. Florida Medicaid has separate authorization rules. Florida workers' compensation under F.S. Chapter 440 imposes Florida-specific authorization and documentation timelines that differ materially from commercial billing.

How MIPS Value Pathways change documentation expectations

Beginning with the 2026 performance year, CMS continues to develop MIPS Value Pathways (MVPs) tailored to clinician specialty. The Functional Limitation Reduction MVP is the primary PT pathway, and the underlying measures (functional outcome assessment using a standardized tool, patient-reported outcomes, medication reconciliation, falls screening) drive documentation patterns that need to be in place before the performance year begins.

Practices below the MIPS low-volume threshold ($90,000 Medicare allowed AND 200 Medicare patients AND 200 covered services) are not required to participate; voluntary participation is permitted but does not change the threshold for the following year.

How d3rx fits

The d3rx specialty compliance binder maintains the PT Medicare module: plan-of-care certification tracker, 90-day recertification tracker, KX modifier ledger, CQ/CO modifier reconciliation, internal coding audit log, TPE response binder, and MIPS quality measure documentation. It is a source-grounded administrative documentation aid. It does not certify compliance, provide legal advice, or replace counsel. See compliance binder for the binder structure or audit defense for TPE/RAC/UPIC response support.

D3rx compliance guides are administrative documentation aids. They do not certify compliance, provide legal advice, replace counsel, or guarantee an audit outcome. The practice remains responsible for reviewing, adopting, and maintaining its compliance program.