A modifier provides the means by which the reporting physician or provider can indicate that a service or procedure that has been performed has been altered by some specific circumstance but not changed in its definition or code.
Level I modifiers are codes and descriptors copyrighted by the American Medical Association's current procedural terminology (CPT).
Level II modifiers are codes and descriptors approved and maintained jointly by the alpha-numeric editorial panel (consisting of CMS, the Health Insurance Association of America, and the Blue Cross and Blue Shield Association).
|A1||Dressing for one wound|
|A2||Dressing for two wounds|
|A3||Dressing for three wounds|
|A4||Dressing for four wounds|
|A5||Dressing for five wounds|
|A6||Dressing for six wounds|
|A7||Dressing for seven wounds|
|A8||Dressing for eight wounds|
|A9||Dressing for nine or more wounds|
|AA||Anesthesia services performed personally by anesthesiologist|
|AD||Medical supervision by a physician: more than four concurrent anesthesia procedures|
|AI||Principal physician of record|
|AJ||Clinical social worker|
|AK||Non participating physician|
|AM||Physician, team member service|
|AO||Alternate payment method declined by provider of service|
|AP||Determination of refractive state was not performed in the course of diagnostic ophthalmological examination|
|AQ||Physician providing a service in an unlisted health professional shortage area (hpsa)|
|AR||Physician provider services in a physician scarcity area|
|AS||Physician assistant, nurse practitioner, or clinical nurse specialist services for assistant at surgery|
|AT||Acute treatment (this modifier should be used when reporting service 98940, 98941, 98942)|