HCPCS modifier
A modifier does not replace the procedure code. The page shows the CMS long description. It does not show a CPT descriptor.
Source: CMS HCPCS October 2026 ANWEB file, dated September 23, 2026.
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Definition · Codes and claim data
HCPCS modifier
An HCPCS modifier is a two-character code that adds detail to a procedure or service code. Level II modifiers come from the CMS quarterly file. This site lists 384 of them from the October 2026 file dated September 23, 2026. Modifier AA is anesthesia performed personally by the anesthesiologist. The lookup is at /hcpcs/modifiers.
Questions
HCPCS modifier, answered
Where is the modifier list?
The modifier list is at /hcpcs/modifiers. Each two-character code has its own page.