Anesthesia modifiers can be used to clarify a CPT code for a service that is billed. The modifiers can be used to alter a service without having to change a CPT code.
Anesthesia modifiers also add information to a code and eliminate or prevent unbundling or duplicate billing. They increase code consistency, editing, reimbursement accuracy, and capturing data.
Make sure to submit the anesthesia modifiers correctly on claims that are committed to the national government services. Incorrect claims will need manual intervention and cause delays.
Anesthesia modifiers billed to Medicare must include at least one of the modifiers below.
Anesthesia Pricing Modifiers
An anesthesia pricing modifier has to be listed in the first position in order to receive reimbursement.
AA Modifier description: Anesthesia services are personally performed by an anesthesiologist.
Payment for modifier AA for anesthesia claims is 100% allowable. This modifier allows full fee schedule reimbursement.
AA Modifier description: Medical supervision by an anesthesiologist: more than 4 concurrent anesthesia procedures.
Payment for anesthesia claims for modifier AD is 100% allowable.
AD Modifier description: Medical direction of 2, 3, or 4 concurrent anesthesia procedures involving qualified individuals.
Modifier AD limits payment to 50% of the amount that would have been allowed if personally performed by an anesthesiologist or nonsupervised CRNA.
Read more about the billing guidelines for Modifier AD here.
QK Modifier description: Medical direction of two, three, or four concurrent anesthesia procedures involving qualified individuals.
Payment for anesthesia claims for modifier QK is 50% allowable.
QS Modifier description: Monitored anesthesia care service. Payment for anesthesia claims for modifier QS is 100% of allowable.
QX Modifier description: CRNA service with medical direction by an anesthesiologist.
Modifier QX limits payment to 50% of the amount that would have been allowed if personally performed by an anesthesiologist or nonsupervised CRNA.
Read more about the billing guidelines for Modifier QX here.
QY Modifier description: Anesthesiologist medically directs one CRNA.
Modifier QY limits payment to the anesthesiologist and CRNA to 50% of the amount that would have been allowed if personally performed by the anesthesiologist.
Read more about the billing guidelines for Modifier QY here.
QZ Modifier description: CRNA service without medical direction by an anesthesiologist.
Modifier QZ has no effect on payment and the allowed amount is what would have been allowed if personally performed by an anesthesiologist. Payment for anesthesia claims for modifier QZ is 100% allowable.
Read more about the billing guidelines for Modifier QZ here.
33 Modifier description: Preventive Services.
Medicare deductible and coinsurance will be waived if modifier 33 is appended to CPT 00810 for anesthesia services.
PT Modifier description: A colorectal cancer screening test that led to a diagnostic procedure. This modifier is appended to anesthesia CPT code 00810 and will waive the Medicare deductible.
Anesthesia Physical Status Modifiers
If physical status modifiers P3, P4, or P5 are billed, the full unit value for these physical status modifiers will be reimbursed even if the obstetrical delivery total maximum allowable points have been met.
P1 Modifier description: A normal healthy patient.
P2 Modifier description: A patient with mild systemic disease.
P3 Modifier description: A patient with severe systemic disease.
One additional time unit is allowed.
P4 Modifier description: A patient with severe systemic disease that is a constant threat to life.
Two additional time units are allowed.
P5 Modifier description: A moribund patient who is not expected to survive without the operation.
Three additional time units are allowed.
P6 Modifier description: A declared brain-dead patient whose organs are being removed for donor purposes.
Anesthesia Informational Modifiers
Anesthesia informational modifiers shall be placed in the second modifier position.
QS Modifier description: Monitored anesthesia care (MAC).
G8 Modifier description: MAC for deep complex complicated or markedly invasive surgical procedures and may be used in lieu of modifier QS.
G9 Modifier description: MAC for a patient who has a history of severe cardiopulmonary condition and may be used in lieu of modifier QS.
GC Modifier description: Performed by a resident under the direction of a teaching physician: the provider must also use one of the other pricing modifiers in the first modifier position.
Surgical Anesthesia Modifiers
Anesthesia procedures are billed with the CPT codes that can be found in the manual in the Anesthesia section.
Reimbursement for surgical anesthesia services is calculated based on a conversion factor, time units of 15 minutes, and base units.
A flat fee is used for reimbursement for maternity-related procedures and moderate sedation. General anesthesia for vaginal delivery is an exception.
Report minutes on anesthesia claims. Only leave it out if the policy states otherwise.
Bill surgical anesthesia services with the following anesthesia modifiers:
- Modifier QZ: CRNA service without medical direction by an anesthesiologist.
- Modifier QX: CRNA service with direction by an anesthesiologist.
- Modifier QK: Anesthesiologist Medical direction of two, three, or four concurrent anesthesia procedures involving qualified individuals.
- Modifier QY: Anesthesiologist Medical direction of one CRNA.
- Modifier AA: Anesthesiologist Anesthesia services performed personally by the anesthesiologist.
The following is an explanation of billable modifier combinations:
- Legitimate modifier combinations: Modifier QK and QX QY and Modifier QX
- Modifiers that need a partner: Modifier QK, Modifier QX, and Modifier QY.
- Modifiers that can stand alone: Modifier AA and Modifier QZ.
Position Of Modifiers On Anesthesia Claims
Document anesthesia modifier in the first position to indicate whether the service was medically directed, medically supervised, or personally performed.
Claims submitted without anesthesia modifiers in the correct position can result in rejections or processing delays.
Anesthesia Modifier Reimbursement
Below are the maximum allowable fees for anesthesia services billed as MD supervision of a CRNA for Blue Cross and Blue Shield of Texas and HMO Blue Texas.
- Modifier QY reimbursement: $325.52 (MD Medical Direction of a CRNA).
- Modifier AD reimbursement: $162.76 (MD supervision of a CRNA).
- Modifier QK reimbursement: $310.01 (MD Medical Direction of a CRNA).