The KX modifier and Medicare's yearly therapy threshold

Medicare Part B has a yearly dollar amount for outpatient therapy, per patient. Once a patient's therapy for the calendar year passes it, Medicare still pays, but only when the provider adds the KX modifier to each claim line. The KX modifier is the provider's attestation that the services are medically necessary and that the documentation supports it.

• Two amounts, not one. Physical therapy and speech-language pathology share one threshold; occupational therapy has its own.
• It is per patient, per calendar year, across all providers. Therapy the patient received at another clinic earlier in the year counts toward the same amount.
• The amount changes each year. CMS publishes it annually: our research puts the 2026 amount at $2,480. Check the current CMS figure before relying on it.
• Without the KX modifier above the threshold, the line is denied and can't be billed to the patient unless an Advance Beneficiary Notice was signed first.
• Higher spending can trigger review. Above a second amount (the targeted medical review threshold, $3,000 in recent years), claims may be selected for medical review, so the documentation matters even more.

Your own records only show the therapy your clinic provided. A patient who saw another therapist earlier in the year may already be close to, or past, the threshold on their first visit with you. Medicare's eligibility information shows how much of the threshold the patient has already used, which is why checking it at intake, and again as the year goes on, matters.

• Check therapy amounts already used when a Medicare patient starts with you, and again as their plan of care continues.
• Track each patient's running total for the year, for physical therapy and speech-language pathology together and for occupational therapy separately.
• Add KX only when it is true: the services are medically necessary and the note shows why.
• Give an ABN when the patient wants services that may not be medically necessary above the threshold.

• CO-97: bundling denials, including the 97140 and 97530 pair.
• CO-151: unit limits, including the one-evaluation-per-day limit.

This guide is general information, not legal or billing advice. Always check the current CMS threshold amounts and your contractor's guidance.