CY2026 PFS · Physical Therapy Billing Services

Bill the PTA correctly, or leave 15% on the table twice.

Here is the short answer. When a physical therapist assistant furnishes more than 10% of the time for a therapy service, you must append the CQ modifier, and Medicare pays that service at 85% of the fee schedule amount. That is the de minimis standard. Get the 10% math wrong and you either under-bill compliant work or trigger takebacks on services that should have carried CQ. Under the CMS CY2026 Physician Fee Schedule, the CQ reduction, the annually indexed KX threshold, and 90-day recertification all move together, and this page shows exactly how.

Modifier CQ = PTA-furnished De minimis >10% trigger Payment at 85% Recert every 90 days

The numbers that drive the claim

Four thresholds decide whether a PT claim pays clean

10%

The de minimis line. More than 10% of a service's time furnished by a PTA requires the CQ modifier.

15%

The payment reduction. CQ-tagged services pay at 85% of the PFS amount for that line.

90days

Maximum interval before the plan of care must be recertified, or sooner if the POC changes.

$3,000

Targeted medical review threshold, held at this level by statute through CY2027.

None of these are new for 2026, but every one is re-stated and re-priced in the CMS CY2026 Physician Fee Schedule Final Rule. The values below reference the current published rules by name so your billers are not guessing.

Layered explainer

Three layers, stacked in the order your claim hits them

1 When CQ appliesThe CQ modifier is a documentation fact, not a billing preferenceCQ answers one question per service line: did a PTA personally furnish the service, in whole or in part, beyond the de minimis amount? If yes, CQ goes on that line. It is line-level, not claim-level, so on the same visit one CPT code can carry CQ while another does not.
CQ = PTA-furnished physical therapy (CO is the occupational therapy assistant equivalent, never interchange them).
Applies whether the PTA works alone or alongside the PT on the same timed or untimed service.
Report CQ in addition to, not instead of, the GP therapy discipline modifier.
Source: CMS CY2026 Physician Fee Schedule Final Rule; Medicare Claims Processing Manual, Ch. 5 (therapy services).
2 How de minimis is calculatedThe 10% test is measured per service, against total service timeDe minimis is the escape hatch. If the PTA's portion of a given service is 10% or less of the total time for that service, CQ is not required. Cross that line by even one minute of the relevant time bucket and CQ applies to the whole line at 85%. The calculation is done service by service, not by rolling up the visit.
Timed codes: compare PTA minutes to total minutes for that specific timed service.
Untimed and supervised-modality codes follow the same "more than 10% of the service" logic per the final policy.
Document the split contemporaneously. The minute math is the audit trail when a payer asks.
Source: 42 CFR 410.59/410.60; CQ/CO de minimis standard as finalized and carried into CY2026 PFS.
3 How recert timing interactsAn expired plan of care sinks the claim before CQ ever mattersThe cleanest CQ math in the world does not pay if the plan of care lapsed. Medicare requires the POC to be certified at the start and recertified at least every 90 days, or whenever the plan is significantly revised. A PTA can deliver treatment under an active, physician-certified plan, but the certification clock is independent of who furnished the minutes.
Recert is due by day 90 of the certified interval, signed by the physician or non-physician practitioner.
A PTA cannot establish or recertify a plan of care, only furnish care under one.
Late recert plus KX-flagged, over-threshold visits is the highest-risk denial pattern we see.
Source: Medicare Benefit Policy Manual, Ch. 15, §220; 42 CFR 424.24 (certification and recertification).

Worked example

The 10% line in practice, two archetype visits side by side

Same CPT code, opposite outcomes, because of the minute split

Archetype: outpatient ortho clinic, timed 97110NO CQ

PT 92%

PTA share of the service8% ≤ 10%

Payment on this line100% of PFS

Archetype: same clinic, next patient, timed 97110CQ REQUIRED

PT 55%

PTA 45%

PTA share of the service45% > 10%

Payment on this line85% of PFS

de_minimis_met = PTA_minutes / total_service_minutes > 0.10
if de_minimis_met → append CQ → allowed_amount = PFS_amount × 0.85
else → no CQ → allowed_amount = PFS_amount × 1.00

Annual dollar thresholds

Where CQ sits relative to the KX threshold and medical review

The 15% CQ reduction is applied at the line level regardless of dollar totals. The KX threshold and the targeted medical review threshold sit downstream and govern how much scrutiny a beneficiary's cumulative therapy draws. CMS publishes the current-year KX figure in the CY2026 PFS; for reference, the CY2025 combined PT and speech-language pathology threshold was $2,410, and CMS indexes it each year.

Every line

CQ / 85%

Apply the de minimis test and, where met, the 15% reduction on that service. Independent of any dollar cap.

KX threshold

Attest KX

Once combined PT and SLP allowed charges exceed the annually indexed threshold, append KX to attest medical necessity for continued care.

Above $3,000

Targeted MR

Beyond the $3,000 medical review threshold (fixed through CY2027), claims may be selected for targeted review of documentation.

Certification clock

The 90-day plan-of-care cycle a PTA works inside

Day 0

Evaluation and initial certification

The physical therapist evaluates and establishes the plan of care. The physician or NPP certifies it. Only now can a PTA furnish treatment under it.

Days 1–89

Treatment, with CQ applied line by line

PT and PTA deliver care. Each service line gets the de minimis test; CQ and the 85% rate attach wherever the PTA exceeds 10% of that service.

By Day 90

Recertification due

The plan must be recertified by the 90-day mark, or sooner if the plan is significantly modified. Miss it and subsequent visits are exposed regardless of correct CQ coding.

Ongoing

KX attestation as charges accrue

As cumulative allowed charges pass the indexed KX threshold, append KX and keep documentation review-ready against the $3,000 targeted-review line.

Quick reference

CQ present vs absent on the same service

Scenario	PTA share of service	CQ modifier	Line payment	Recert still required?
PT furnishes entire service	0%	No	100% of PFS	Yes, every 90 days
PTA assists, at or under de minimis	≤10%	No	100% of PFS	Yes, every 90 days
PTA exceeds de minimis	>10%	CQ required	85% of PFS	Yes, every 90 days
PTA furnishes full service alone	100%	CQ required	85% of PFS	Yes, every 90 days

Operator to operator

The four checks that stop PTA-related denials before submission

Compute de minimis per service, not per visit

Roll-up math is the most common CQ error. Check every timed and untimed line against its own total time.

Pair CQ with GP, never swap disciplines

CQ rides alongside the PT discipline modifier. CO belongs to OT. Mixing them is an automatic edit.

Watch the recert clock independently of coding

An active, timely-recertified plan of care is the precondition. Flag day-75 so nothing lapses at day 90.

Track KX cumulative charges by beneficiary

Attest KX once the indexed threshold is passed and keep notes review-ready against the $3,000 line.

PTA billing is small math with large recovery consequences.

Across a full PT panel, a mishandled 10% test or a missed 90-day recert quietly compounds into denied lines and takebacks. ASP-RCM Solutions builds the CQ de minimis logic, the KX threshold tracking, and the recertification calendar directly into your physical therapy billing workflow, so the rule fires on every line without your therapists doing arithmetic mid-session.

Talk to our PT billing team →

This page is general billing education, not legal, coding, or reimbursement advice. Threshold dollar figures are indexed annually; confirm current-year values against the CMS CY2026 Physician Fee Schedule Final Rule and your MAC's guidance before submission. Examples use anonymized practice archetypes.