HCPCS Level II modifier
Modifier GX
Modifier GX is a HCPCS Level II modifier. CMS describes it as: Notice of liability issued, voluntary under payer policy.
Source: CMS HCPCS Level II, October 2026 file dated September 23, 2026. Publisher page
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- Modifier
- GX
- Type
- HCPCS Level II modifier, maintained by CMS
- CMS description
- Notice of liability issued, voluntary under payer policy
- Claim form
- CMS-1500 item 24D, up to four modifiers per line. 837P SV101-3 to SV101-6.
- Guidance
- CMS HCPCS quarterly update
Liability notices and coverage
- GAWaiver of liability statement issued as required by payer policy, individual case
- GYItem or service statutorily excluded, does not meet the definition of any medicare benefit or, for non-medicare insurers, is not a contract benefit
- GZItem or service expected to be denied as not reasonable and necessary
- KXRequirements specified in the medical policy have been met
Related modifiers
- GAWaiver of liability statement issued as required by payer policy, individual case
- GYItem or service statutorily excluded, does not meet the definition of any medicare benefit or, for non-medicare insurers, is not a contract benefit
- GZItem or service expected to be denied as not reasonable and necessary
- KXRequirements specified in the medical policy have been met
- GWService not related to the hospice patient's terminal condition
- GVAttending physician not employed or paid under arrangement by the patient's hospice provider
- H9Court-ordered
- GUWaiver of liability statement issued as required by payer policy, routine notice
Related pages
- All CPT and HCPCS modifiersA to Z list
- CMS-1500 claim formModifiers go in item 24D
- Denial code CO-4Modifier missing or does not fit the code
- Denial code CO-182Modifier invalid on the date of service
- Denial code CO-50Not medically necessary
- Denial code CO-96Non-covered charge
- HCPCS Level II code lookup
- Denial and remark codes
Questions
What does modifier GX mean?
Modifier GX is a HCPCS Level II modifier. CMS describes it as: Notice of liability issued, voluntary under payer policy.
Is modifier GX a CPT or a HCPCS modifier?
GX is a HCPCS Level II modifier from the CMS quarterly HCPCS file. Two-digit numeric modifiers, such as 25 or 59, are CPT modifiers.
Where does modifier GX go on a claim?
On the CMS-1500 it goes in item 24D next to the procedure code. Each line holds up to four modifiers. On an 837P it goes in SV101-3 to SV101-6.
What denial comes back when a modifier is wrong?
A missing or mismatched modifier often comes back as CARC 4. A modifier that was not valid on the date of service comes back as CARC 182. A bundling edit the modifier should have bypassed comes back as CARC 97 or 236.