Does the 8-minute rule limit how much therapy a patient can get?

No. It is a counting method for converting treatment time into billable units, not a cap on care. Denials attributed to it are almost always documentation problems — the note did not record time in a way that supports the units billed.

What happens when a patient crosses the KX threshold?

Nothing automatic. Coverage does not stop. Continued claims must carry an attestation that skilled therapy remains medically necessary, and the record has to support it. Denials at this point are usually about the documentation behind the attestation rather than the attestation itself.

Will Undeny tell me how many units to bill?

No. Undeny gives no CPT, ICD, unit-count, or modifier advice. Your coder determines what the record supports; Undeny drafts the appeal arguing from that record and the payer's own criteria.

How do I keep continued treatment from reading as maintenance?

Repeat objective measures and document the comparison. A note that records what was done tells a reviewer nothing about progress; the same measure at two points in time, with clinical reasoning about why skilled intervention is still required, is what distinguishes active treatment.

Physical therapy denials: the 8-minute rule and the KX threshold

Two Medicare rules drive most PT denials: how timed treatment converts into billable units, and what happens once a patient crosses the annual therapy threshold.

The rules behind the denials

The 8-minute rule: Medicare's method for converting time spent on timed treatment into billable 15-minute units. A unit requires at least 8 minutes of that service. It governs how time is counted and reported — it is not a limit on how much therapy a patient may receive.
The KX modifier threshold: Once a beneficiary's cumulative therapy charges pass an annual dollar threshold, continued claims must carry an attestation that the services remain medically necessary, supported by the record. The old hard therapy cap was repealed; this attestation replaced it.
The targeted medical review threshold: A second, higher annual figure above which claims may be selected for targeted review. Crossing it is not a denial and not a limit — it raises the likelihood that documentation is examined.

The numbers

KX threshold, 2026 (PT and speech-language pathology, combined): $2,480; Up from $2,410 in 2025. Occupational therapy has its own separate threshold. Verify the current figure against CMS before relying on it — it is updated annually.
Targeted medical review threshold: $3,000; Held at this figure through 2028. Reaching it means claims may be selected for review, not that payment stops.

Why these denials fire

01Treatment time was recorded in the note but not in a form that shows how the billed units were derived.
02The patient crossed the annual threshold and subsequent claims went out without the required attestation.
03The attestation was present but the record did not demonstrate continued medical necessity for skilled therapy.
04Documentation described supervised activity rather than skilled therapy requiring a therapist's expertise.
05The plan of care or certification lapsed during the treatment episode.
06Progress toward functional goals was not documented, so continued treatment read as maintenance.

Documentation that wins

Treatment minutes recorded per service, with start and stop times where your documentation supports it.
A plan of care with measurable functional goals and current certification dates.
Objective measures repeated over time — the comparison is what demonstrates progress.
Clinical reasoning showing why the therapist's skill was required, not merely that activity occurred.
For threshold cases, an explicit statement of why skilled therapy remains necessary at this point in the episode.

Arguments that work

The record documents the treatment time supporting the units as billed.
Skilled therapy remained medically necessary past the threshold, and the record shows the clinical reasoning.
Objective measures demonstrate ongoing functional progress, so this is not maintenance therapy.
The plan of care and certification were in force for the dates of service in dispute.

What Undeny will not do

Undeny does not advise on unit counts, CPT selection, or modifier application. Those are your therapist's and coder's determinations against the record and the current CMS rules. What Undeny does is argue the appeal from the documentation once those determinations are made.

Where to go next

Source: CMS — Therapy Services

Common questions

Does the 8-minute rule limit how much therapy a patient can get?: No. It is a counting method for converting treatment time into billable units, not a cap on care. Denials attributed to it are almost always documentation problems — the note did not record time in a way that supports the units billed.
What happens when a patient crosses the KX threshold?: Nothing automatic. Coverage does not stop. Continued claims must carry an attestation that skilled therapy remains medically necessary, and the record has to support it. Denials at this point are usually about the documentation behind the attestation rather than the attestation itself.
Will Undeny tell me how many units to bill?: No. Undeny gives no CPT, ICD, unit-count, or modifier advice. Your coder determines what the record supports; Undeny drafts the appeal arguing from that record and the payer's own criteria.
How do I keep continued treatment from reading as maintenance?: Repeat objective measures and document the comparison. A note that records what was done tells a reviewer nothing about progress; the same measure at two points in time, with clinical reasoning about why skilled intervention is still required, is what distinguishes active treatment.

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