Physical therapy billing
Units, modifiers and plan-of-care dates checked before every PT claim goes out.
We bill physical therapy the way Medicare counts it: timed units under the 8-minute rule, GP on every line, KX past the $2,480 threshold for 2026, CQ for assistant care, and plans of care certified on time.
- Full-service rate
- 3% to 6% of collections
- 2026 KX threshold
- $2,480, PT and SLP combined
- Medicare rules
- 8-minute rule, GP, KX, CQ
- New & smaller practices
- Flexible monthly minimum
What makes physical therapy billing different
A physical therapy claim is mostly time. Most PT codes are billed in 15-minute units, so the units on the claim have to match the timed minutes in the note, and Medicare checks a modifier on every line: GP for the discipline, KX past the yearly threshold, CQ when an assistant treated.
Get one of those wrong and the claim denies, pays short, or turns into an overpayment later. We check the note, the units and the modifiers for each visit before the claim reaches the payer, as part of our full revenue cycle service at 3% to 6% of collections.
The Medicare rules on every PT claim
With 2026 figures. Medicaid and commercial plans set their own rules, so we bill each one to its written policy.
- 8-minute ruleTimed codes are billed from the day’s total timed minutes: 8 to 22 minutes is 1 unit, 23 to 37 is 2, 38 to 52 is 3, 53 to 67 is 4.
- GP modifierRequired on every line under a PT plan of care, the evaluation included. GO is for occupational therapy, GN for speech.
- KX modifierAdded once a patient’s allowed PT and speech therapy amounts for 2026 pass $2,480. Lines over it without KX are denied.
- Medical reviewClaims past $3,000 for the year can be picked for targeted review, so the notes have to carry the case.
- CQ modifierPaired with GP when a PTA furnished more than 10 percent of a service on their own. Medicare pays the line at 85 percent.
- Plan of careCertified within 30 days of the first treatment, then recertified at least every 90 days or when the plan changes.
- Same-day reductionAfter the service with the highest practice expense, each further always-therapy service that day has its practice expense payment cut 50 percent.
- Functional reportingThe G-codes and severity modifiers ended for dates of service from January 1, 2019.
The 8-minute rule, worked through
Under chapter 5 of the Medicare Claims Processing Manual, you add up the minutes of all timed codes in a day and bill units from the total, in 15-minute steps. A single timed service under 8 minutes is not billed, and the note must show the total timed minutes.
CMS’s own example: 33 minutes of therapeutic exercise (97110) and 7 minutes of manual therapy (97140) make 40 minutes, so 3 units. You bill 2 units of 97110 and 1 of 97140, because the 7 minutes of manual therapy is more than the 3 minutes left over from 97110.
Untimed codes, such as the PT evaluations (97161 to 97163), are one unit however long they take. Commercial and Medicaid plans can count units their own way, and we follow each plan’s policy.
KX, CQ and plan-of-care dates
For 2026, CMS set the KX modifier threshold at $2,480 for PT and speech-language pathology combined, with a separate $2,480 for occupational therapy. Past it, each line needs KX to confirm the care is medically necessary and documented, or it is denied. Claims past $3,000 can be selected for targeted medical review.
When a physical therapist assistant furnishes more than 10 percent of a service on their own, the line carries CQ next to GP and Medicare pays 85 percent of the fee schedule amount. Minutes the PTA spends treating together with the PT count as the PT’s.
The plan of care must be certified by a physician or NPP within 30 days of the first treatment and recertified at least every 90 days, under 42 CFR 424.24. Since 2025, the initial certification needs no signature when a written order or referral is on file and you can show the plan was sent within 30 days of the evaluation. We track these dates for every patient.
NCCI edits and the denials PT clinics see
The 2026 NCCI policy manual allows one therapy service per 15-minute period, except supervised modalities (97010 to 97028). Where an edit pairs two timed codes, modifier 59 or XU is correct only when they were done in separate intervals. APTA’s list of common PT code pairs shows group therapy (97150) edited against one-on-one codes such as 97110, 97140 and 97530, and manual therapy (97140) never paid with massage (97124).
Common PT denials, with the reason codes that often carry them (codes vary by payer):
- Modifier inconsistent with the code (CO-4): GP, KX or CQ wrong or missing
- Bundled (CO-97 or CO-236): two codes in the same 15 minutes, or 59 without separate intervals
- Units not supported (CO-151): more units than the timed minutes allow
- Not medically necessary (CO-50): no certified plan of care, or notes that do not show skilled care
- Benefit limit reached (CO-119): a plan’s yearly visit cap
- Authorization absent (CO-197): no approval on file where the plan requires one
Each goes through our denial management process, corrected and resubmitted or appealed with the note and plan of care. Our denial code guides explain what each code means and how it is fixed.
How we run physical therapy billing
Map each payer’s rules
Medicare, Medicaid and every commercial plan you bill get their unit, modifier, visit-limit and authorization rules set up before the first claim.
Track every plan of care
Certification and recertification dates, visit counts and each patient’s running total against the KX threshold are tracked per patient.
Check every visit
Timed minutes, units, GP, KX and CQ are checked against the note, and NCCI edits are scrubbed before the claim goes out.
Work what comes back
Unpaid and denied claims are worked by payer and reason code until they are paid or closed with a reason.
Report monthly
Collections, days in A/R, denials by reason and claims close to a deadline, by payer and by therapist.
Credentialing for physical therapists
Medicare screens physical therapists in private practice at its moderate-risk level, which means an on-site visit as part of enrollment. PTs cannot opt out of Medicare, so a PT who treats Medicare patients enrolls. Some commercial plans credential therapists through a separate network company, which UnitedHealthcare does through OptumHealth Physical Health.
What changes for these providers, step by step: see physical therapy credentialing.
Not sure your units and modifiers are right? Send us a month of PT claims with the notes and we’ll check them, free.
Physical therapy billing questions
Something else? Call +1 786-788-7313. A biller answers.
All questionsIt is Medicare’s method for billing timed 15-minute codes. You add the minutes of all timed services in a day and bill units from the total: 8 to 22 minutes is one unit, 23 to 37 is two, 38 to 52 is three. A single timed service under 8 minutes is not billed, and the note must show total timed minutes.
$2,480 for physical therapy and speech-language pathology combined, and a separate $2,480 for occupational therapy. Once a patient’s total for the year passes it, each line needs the KX modifier, confirming the care is medically necessary and documented, or Medicare denies it. Claims past $3,000 can be selected for targeted medical review.
When a physical therapist assistant furnishes more than 10 percent of a service on their own. CQ goes on the line next to GP, and Medicare pays 85 percent of the fee schedule amount. Time the PTA spends treating together with the PT counts as the PT’s, and CMS sets two exceptions for the final units of a visit.
At least every 90 days, and sooner when the plan changes significantly. The initial certification should be signed within 30 days of the first treatment. Since 2025, Medicare waives that first signature when a written order or referral is on file and you can show the plan went to the physician or NPP within 30 days of the evaluation.
No. CMS ended functional reporting for therapy services with dates of service from January 1, 2019, so the G-codes and severity modifiers are no longer required on Medicare claims. You still document function, goals and progress in the notes, because medical necessity and the KX modifier depend on them.
Our full-service rate is 3% to 6% of monthly collections, set by your volume, with no setup or onboarding fees and flexible monthly-minimum plans for new and smaller practices. It covers eligibility checks, prior authorizations, coding, claims, payment posting, denials and A/R follow-up, plus unit and modifier checks and plan-of-care tracking. Your exact rate comes after a free A/R review. Our guide to medical billing costs shows how to compare quotes.
Yes. We don’t list our clients on this site, but ask us and we’ll arrange it: with a current client’s permission, we share their contact details so you can hear how we work from them directly.
From our guides
How to calculate days in A/R
The formula with a worked example and a calculator, the benchmarks, why a good average can hide old claims, and the fixes that bring days in A/R down.
How much do medical billing services cost?
The four ways billing companies price their work, the fees that sit outside the rate, and in-house arithmetic built from BLS data, so you can compare quotes on your own numbers.
Send us your last 90 days of PT claims.
We’ll review them free and show you where units, modifiers or plan-of-care dates are costing you money.