AO HCPCS Level II modifier: Alternate payment method declined by provider of service
AO is a HCPCS Level II modifier: “Alternate payment method declined by provider of service.” It adds this detail to the code it is reported with.
Official description
AOAlternate payment method declined by provider of service
Short description: Prov declined alt pmt method
HCPCS · United States
Medicare details
The indicators CMS publishes with AO in its October 2026 file. They describe Medicare’s handling, not another payer’s.
- Medicare coverage
- Carrier judgment
- Added
- Oct 1, 2013
Where AO sits
- 1GroupHCPCS modifiers
- 2Modifier AOAlternate payment method declined by provider of service
Source and release
- Data release
- HCPCS Level II · October 2026
- Effective date
- Oct 1, 2026
- Publisher
- CMS
This page is built from the HCPCS Level II catalog that Vero Codes reads when it suggests codes: Centers for Medicare & Medicaid Services’s October 2026 release, imported from the publisher’s file and checked against it. The description, notes and structured data come from the same record.
Frequently asked questions
What does HCPCS code AO mean?
AO is the HCPCS code for “Alternate payment method declined by provider of service” in CMS’s HCPCS Level II October 2026 release.
Where is AO in the HCPCS Level II list?
AO is listed under Modifiers.
Does Medicare cover AO?
CMS lists AO’s Medicare coverage as “Carrier judgment”. Coverage and payment still depend on the patient, the setting, the documentation and the payer.
Which HCPCS Level II release does this page use?
It uses CMS’s October 2026 release, in effect from Oct 1, 2026 to Dec 31, 2026. It is a reference: confirm the code against the current list and the payer’s rules before you submit it.
Codes beside AO
All modifiersAGPrimary physicianAHClinical psychologistAIPrincipal physician of recordAJClinical social workerAKNon participating physicianAMPhysician, team member serviceAPDetermination of refractive state was not performed in the course of diagnostic ophthalmological examinationAQPhysician providing a service in an unlisted health professional shortage area (hpsa)ARPhysician provider services in a physician scarcity areaASPhysician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgeryATAcute treatment (this modifier should be used when reporting service 98940, 98941, 98942)AUItem furnished in conjunction with a urological, ostomy, or tracheostomy supply