KX Modifier: Medicare Therapy Threshold Rules for 2026
The KX modifier attests that Medicare's policy requirements are met. How it works with the 2026 therapy threshold, the $3,000 review level, and DME claims.
The KX modifier is a HCPCS Level II modifier that tells Medicare the requirements in the applicable medical policy have been met and the documentation is in the record. In outpatient therapy, it's the attestation you add once a patient's therapy for the year passes the KX threshold: $2,480 for physical therapy and speech-language pathology combined, and $2,480 for occupational therapy, in 2026.
Key takeaways
- KX is CMS content. Its descriptor: "Requirements specified in the medical policy have been met."
- 2026 therapy thresholds: $2,480 for PT and SLP combined, $2,480 for OT (CMS, CY 2026 PFS final rule).
- Therapy claims above the threshold without KX are denied.
- KX means the services are medically necessary and documented. It isn't a way to keep billing routine care.
- Above $3,000 per discipline group, claims may be picked for targeted medical review.
Modifier KX · payment effect
With and without the modifier
97110 without KX · national office
$29.06
Therapeutic exercise
97110-KX · No change to the rate
$29.06
Attests the services are medically necessary and documented (e.g. therapy above the annual threshold). It doesn’t change the rate.
What the KX modifier means
Because KX is a HCPCS Level II modifier, its definition is CMS text and can be quoted: "Requirements specified in the medical policy have been met." It's an attestation, not a payment adjustment. Medicare uses it in several places where a policy sets conditions for coverage:
- Outpatient therapy above the annual KX threshold (the most common use).
- Durable medical equipment, prosthetics, orthotics and supplies, where a local coverage determination lists criteria the supplier must meet before billing, and KX says they were met.
- Other services whose policy articles tell you to add KX when the documented criteria are satisfied.
How the therapy threshold works
Congress replaced the old therapy caps with thresholds in the Bipartisan Budget Act of 2018. CMS says section 50202 "preserves the former therapy cap amounts as thresholds above which claims must include the KX modifier as a confirmation that services are medically necessary as justified by appropriate documentation in the medical record."
Two separate amounts accrue each calendar year: one for physical therapy and speech-language pathology together, and one for occupational therapy. Once a patient's therapy in a group passes the threshold, every further claim line in that group needs KX along with the discipline modifier (GP, GO or GN).
The targeted medical review threshold stays at $3,000 for each group until it starts indexing annually in 2028. Crossing it doesn't mean every claim is reviewed; CMS says the review is targeted.
When to use the KX modifier
- The patient has passed the 2026 threshold in that discipline group, and the treatment is still medically necessary: goals are being met, skilled care is still needed, and the plan of care and progress notes show it.
- Each line above the threshold. A typical PT visit then carries three modifiers on a timed code such as 97110: GP, KX and, where a physical therapist assistant furnished part of it, CQ.
- DME and supply claims when the LCD's criteria are met and documented.
Use the 8-minute rule calculator to check that the units on those lines are right before attesting to them.
When not to use the KX modifier
Also don't use KX:
- Below the threshold. It isn't needed and adds nothing.
- Without the discipline modifier. Therapy codes still need GP, GO or GN.
- To signal a non-covered service. That's GY for statutorily excluded services or GA with a valid ABN.
How the KX modifier affects payment
KX has no payment percentage. A line with KX is paid at the normal fee schedule amount, still subject to the therapy multiple procedure reduction and, where an assistant was involved, the 15% CQ or CO reduction. Above the threshold, a line without KX is denied.
Therapy MPPR
Same-day therapy units after the practice-expense reduction
National payment after MPPR
$100.70
Without the reduction: $120.91 · reduction $20.21 (16.7%)
KX vs GA, GY and GP
| Modifier | What it says | When |
|---|---|---|
| KX | Policy requirements met, documentation on file | Therapy above the threshold; DME criteria met |
| GA | Expected denial; ABN on file | Service likely not reasonable and necessary |
| GY | Statutorily excluded or not a Medicare benefit | Service Medicare never covers |
| GP | Under a physical therapy plan of care | Every outpatient PT line |
FAQ
What is the KX modifier for?
To attest that a policy's coverage requirements have been met and documented. In therapy, it's required on claims after a patient's annual therapy passes the KX threshold, confirming the care is still medically necessary.
Is KX a valid modifier?
Yes. KX is an active HCPCS Level II modifier that Medicare uses for outpatient therapy above the threshold and for many DMEPOS policies.
What does the KX modifier mean in medical billing?
That the requirements in the applicable medical policy have been met, with documentation on file. It doesn't change the amount paid.
How do you use the KX modifier for Medicare?
Track each patient's therapy spending for the year by group (PT and SLP combined; OT separately). Once it passes the threshold ($2,480 per group in 2026), add KX to each medically necessary line along with GP, GO or GN, and keep documentation that supports continued skilled care.
Is there still a Medicare therapy cap?
No hard cap. The old cap amounts became the KX thresholds in 2018. Medically necessary therapy above them is paid when the claim carries KX.
Keep reading
- 8-minute rule calculator for timed therapy units.
- Modifier GP, GA and GY for the other therapy and liability modifiers.
- Modifier 59 for bundled therapy code pairs.
- Codes on this page: 97110 97530 97140 97161
Sources: CMS, Therapy Services (CY 2026 updates, page modified March 10, 2026); CMS MLN Matters MM14315, CY 2026 PFS final rule summary; Palmetto GBA, HCPCS Modifier KX (published December 3, 2025). Verified October 6, 2026.
