The KX modifier appears on two very different kinds of claims: DMEPOS items governed by a medical policy, and outpatient therapy services that have passed a yearly dollar threshold. It is also one of the easiest modifiers to misuse, because it is not a general “all good” flag. This guide covers what KX means in each setting, when it is required, and how it relates to the GA, GY and GZ modifiers.
Last reviewed: October 2026. Thresholds and policy articles change; confirm against CMS and your DME MAC before billing.
What KX means on DMEPOS claims
On DME, prosthetics, orthotics and supplies, KX means that the requirements specified in the medical policy have been met. In other words, you are attesting that the item’s Local Coverage Determination (LCD) criteria are satisfied and documented.
Key point: KX is required only for items whose LCD requires it. It is not meant to be added to every DME claim line.
When KX is required, and when it is not
Your DME MAC lists which items need KX. Examples in Noridian’s guidance include power mobility devices, positive airway pressure (PAP) devices, negative pressure wound therapy and wheelchair seating, and the criteria differ by LCD. Noridian also states that KX billed with other DMEPOS items is inappropriate usage, and that if the LCD requirements are not met the KX modifier must not be used. Note that the page containing that language was last updated in 2017, so check it against your MAC’s current policy article.
KX, GA, GY and GZ: how they fit together
| Modifier | Meaning | Use when |
|---|---|---|
| KX | Requirements specified in the medical policy have been met | The LCD criteria are met and documented |
| GA | Waiver of liability statement on file; valid ABN obtained | Coverage is expected to be denied as not reasonable and necessary, and a valid ABN was signed |
| GY | Item or service statutorily excluded or does not meet the definition of a Medicare benefit | The item is not a Medicare benefit at all |
| GZ | Item or service expected to be denied as not reasonable and necessary | No ABN was obtained; Noridian notes these items are denied automatically |
These modifiers control who is financially responsible. Reporting GA without a valid Advance Beneficiary Notice is not allowed, and picking the wrong one can shift liability for the item. See our ABN forms guide for the notice itself.
An example: oxygen claims
Oxygen claim lines show how strict the rules are. DME MAC guidance says each oxygen claim line needs one of KX, GA, GY or GZ, and lines submitted without one are rejected as missing information. That example is specific to oxygen; do not assume every DME item works the same way.
Tip: build a short LCD checklist for each item you bill often, with the exact criteria that must be documented before KX is added. If a criterion is missing, the answer is not KX plus a hope; it is either getting the documentation or using the appropriate liability modifier.
KX on outpatient therapy claims
For physical therapy, occupational therapy and speech-language pathology, KX has a different job. CMS sets an annual threshold, and once a patient’s therapy costs go above it, claims must carry the KX modifier along with documentation showing the services are medically necessary, or they are denied. For calendar year 2026, the KX threshold is $2,480 for physical therapy and speech-language pathology combined, and $2,480 for occupational therapy.
CMS also keeps a separate, higher manual medical review threshold of $3,000 (for PT and SLP combined and for OT), stated as applying through calendar year 2027. Reaching it does not mean every claim is reviewed; review is targeted.
For specialty-specific detail, see our physical and occupational therapy billing guide and the PT billing denials post.
A note on possible changes
A DME MAC article from 2023 mentioned a pending CMS request for new modifiers that would replace KX, with KX, GA, GY and GZ remaining in use until then. That status may have changed, so check for current instructions before you rely on it.
Common questions
Does every DME claim need KX? No. Only items whose policy requires it.
Is KX the same on DME and therapy claims? No. The code is the same, but the trigger and the documentation requirements are different.
What if the policy criteria are not met? Do not report KX. Use the modifier that matches the situation (such as GA with a valid ABN, or GZ without one) per your MAC’s instructions.
Related guides
- DME Billing Modifiers: NU, RR, KX, GA/GZ, KH/KI/KJ Guide
- DME Rental vs. Purchase Billing: RR, NU, UE, KH, KI, KJ and the 13-Month Cap
- Modifier 25 vs. 59: avoiding bundling denials
- Free Modifier and Place of Service reference tool
- NU, UE and RR Modifiers: Meaning and When to Use Each
- KS vs. KX Modifier: Glucose Monitor Supply Billing
Sources
- Noridian Medicare JD DME, modifiers page (updated April 2026): med.noridianmedicare.com/web/jddme/topics/modifiers
- Noridian, KX modifier billing reminder: noridianmedicare.com
- DME MAC article on oxygen claims and modifiers KX, GA, GY and GZ (revised December 2023): noridianmedicare.com
- CMS therapy services page (thresholds): cms.gov
- CMS Change Request 14252, calendar year 2026 therapy update: cms.gov
This article is educational and is not legal or coding advice. Always confirm current rules with CMS and your DME MAC.
The point that KX is an attestation tied to specific LCD criteria, not a general good-flag, is the part people gloss over. One practical step: before adding KX to a line, open the current LCD and policy article for that exact item and copy the criteria into the chart note as a checklist, then verify each one is documented. If any criterion is missing, hold the claim rather than attaching KX and hoping the reviewer accepts it.