Medicare Therapy Cap Calculator — KX Modifier Threshold

Discipline PT and SLP share one combined allowance. OT has its own, of the same amount.

Therapy charges billed year to date (USD) Example: 1850 Allowed charges for this beneficiary this calendar year, including therapy delivered by other providers.

Current-year KX threshold (USD) Pre-filled with the 2025 amount. CMS re-indexes this every year — confirm the current figure with your MAC and change it here if needed. Verify this figure for the current year — CMS indexes it annually and publishes it with the Physician Fee Schedule. The 2025 amount was 2,410 US dollars; confirm the current value with your MAC before relying on the result.

Remaining before KX

KX modifier required?

Enter charges billed to date to see where this beneficiary stands.

The Threshold Is Not a Cap — and That Distinction Matters

Therapy providers still talk about the “Medicare therapy cap”, and the phrase does real damage because it suggests treatment must stop. It must not. The Bipartisan Budget Act of 2018 permanently repealed the hard cap. What replaced it is a threshold: a per-beneficiary, per-calendar-year dollar figure after which therapy remains fully covered, on the condition that you append the KX modifier and can evidence continued medical necessity.

The practical failure is providers discharging patients who still need skilled therapy because they believe an allowance ran out, or holding claims rather than billing them. Neither is required. The threshold changes your documentation obligation, not the patient's entitlement.

Two Thresholds, and How They Are Grouped

There are two separate figures in play, and they do different jobs.

Threshold	What it triggers
KX modifier threshold (indexed annually)	Append KX to continue billing; attest that services remain medically necessary
Targeted medical review threshold (3,000 USD)	Claims may be selected for targeted review — selection is not automatic

The grouping catches people out more often than the amounts do. Physical therapy and speech-language pathology share a single combined threshold. Occupational therapy has its own, of the same value. A patient receiving both PT and SLP is drawing down one shared allowance, not two, so a practice tracking each discipline separately will believe it has roughly twice the headroom it actually has.

The second trap is that the threshold follows the beneficiary, not the provider. Therapy the patient received from another practice earlier in the same calendar year counts toward the same figure. If a patient transfers to you in August, you are not starting from zero — and you have no way of knowing where you are starting without checking eligibility. Assuming a clean slate is how practices end up billing above the threshold without KX.

What KX Actually Attests To

KX is not an administrative flag you add to clear a system edit. It is an attestation. By appending it you are representing that the services above the threshold are reasonable and necessary, and that the medical record contains documentation supporting continued skilled therapy.

That documentation needs to show more than attendance. It should evidence objective, measurable progress toward stated functional goals, the skilled nature of the intervention — why it required a therapist rather than an aide or a home programme — and a plan of care that is current and certified. Appending KX where none of that exists is a false attestation. The exposure is not a denial; it is a recoupment with an overpayment finding attached, and potentially worse.

Targeted Medical Review Above 3,000 Dollars

Crossing 3,000 US dollars in annual therapy charges does not mean the claim will be reviewed. Review is targeted, and contractors select on pattern rather than on volume alone: a high proportion of patients pushed past the threshold, unusual billing relative to peers, high denial rates, or a concentration of specific codes.

The consequence for a well-run practice is simply that its records need to be capable of supporting the claims it submits. Practices that treat the 3,000 figure as a ceiling and stop short of it are making the same error as those who treated the old cap as a wall — withholding covered care from patients who qualify for it.

The Errors That Cause Threshold Denials

Tracking PT and SLP as separate allowances. They share one. This single misunderstanding produces more above-threshold claims without KX than any other cause.

Assuming the patient starts at zero with you. The threshold follows the beneficiary across providers within the calendar year. Check eligibility on transfer patients.

Adding KX to every claim from the start of the year. Blanket application defeats the purpose of an attestation and is exactly the pattern that attracts targeted review.

Appending KX with no supporting documentation. The modifier asserts medical necessity. If the record cannot demonstrate skilled care and functional progress, the attestation is unsupported.

Stopping treatment at the threshold. There is no cap. Patients who still require skilled therapy remain covered.

More Free Billing Tools & Guides

Therapy billers most often pair this with the 8 minute rule calculator for converting treatment minutes into units, CPT 97110 for therapeutic exercise rules, CO-119 which is the benefit-maximum denial that threshold errors produce, and the physical therapy billing service page. For submission deadlines see the timely filing calculator.

Frequently Asked Questions

What is the Medicare therapy threshold?

It is the annual per-beneficiary dollar amount of outpatient therapy after which you must append the KX modifier to continue billing. It replaced the old hard therapy cap in 2018. Crossing it does not stop payment - it changes what you must attest to and document.

Is there still a Medicare therapy cap?

No. The Bipartisan Budget Act of 2018 permanently repealed the hard cap. What remains is a threshold: once annual therapy charges pass it, services are still covered provided they remain medically necessary and you append the KX modifier attesting to that.

Do physical therapy and speech therapy share a threshold?

Yes. Physical therapy and speech-language pathology share a single combined annual threshold. Occupational therapy has its own separate threshold of the same amount. This catches practices out: a patient receiving both PT and SLP burns through one shared allowance, not two.

What does the KX modifier actually attest to?

That the services above the threshold are reasonable and medically necessary, and that documentation in the medical record justifies continued skilled therapy. Appending KX without that documentation is a false attestation, which is a considerably more serious problem than a denial.

What is the targeted medical review threshold?

A higher annual amount, set at 3,000 US dollars, above which claims may be selected for targeted medical review. Not every claim above it is reviewed - selection is targeted at providers with unusual billing patterns, high denial rates or aberrant utilisation compared with peers.

What happens if I forget the KX modifier above the threshold?

The claim is denied, commonly with a benefit-maximum style denial such as CO-119. It is correctable: resubmit as a corrected claim with the KX modifier appended, provided you are inside the payer's corrected claim window.

Does the threshold reset each year?

Yes. It is a per-beneficiary, per-calendar-year amount and it resets on 1 January. It also follows the patient, not the practice - therapy the patient received elsewhere in the same year counts toward the same threshold, which is why you should check eligibility rather than assume you are starting at zero.