Modifiers indicate a service or procedure that has been performed has been altered by some specific circumstance but not changed in its definition or code.
When selecting the appropriate modifier to be reported with your claim, please ensure that the modifier is valid for the date of service being submitted.
Examples of when modifiers may be used are:
• Identification of only a professional or technical component
• Repeat services by the same or different provider
• An increased, reduced or unusual service
• Billing for components of a global surgical package
• Identification of a specific body area
• To designate a bilateral procedure
• Identification of service in a clinical trial
Coding Guidelines: Modifiers – Complete Listing
Anesthesia Modifiers
Global Surgery Modifiers
Surgical Modifiers
Health Professional Shortage Area (HPSA) and Physician Scarcity Area (PSA) Modifiers
Provider Quality Reporting Initiative (PQRI) Modifiers
Ambulance Modifiers
Other CPT Modifiers
Additional HCPCS Modifiers
Anesthesia Modifiers
One of the following modifiers must be reported with anesthesia services in the first modifier field to indicate who performed the anesthesia service:
Modifier Description
AA Anesthesia services performed personally by anesthesiologist
AD Medical supervision by a physician: more than four concurrent anesthesia procedures.
QK Medically directed by a physician: two, three, or four concurrent procedures
QY Anesthesiologist medically directs one CRNA
QX CRNA service: with medical direction by a physician
QZ CRNA service: without medical direction by a physician
The following modifiers can be reported in the 2nd position under appropriate circumstances in addition to one of the previous anesthesia modifiers:
Modifier Description
QS Monitored anesthesia care service
23 Unusual anesthesia
Note: When using modifier 23, appropriate documentation must be submitted with the claim.
