AA: Use for Anesthesia services personally performed by an Anesthesiologist
- This modifier allows full fee schedule reimbursement.
AD: Use for Medical supervision by an Anesthesiologist when the Anesthesiologist is conducting more than 4 procedures concurrently.
- The Anesthesiologist must be present for each induction, at a minimum.
- The Anesthesiologist is reimbursed for 3 base units plus 1 unit of time per case.
- The CRNA (modifider QX) is reimbursed for fifty percent of each respective case.
QK: This is used when an Anesthesiologist provides medical direction of 2 to 4 concurrent procedures with anesthesia services by qualified individuals, such as CRNAs and AAs.
- This modifier limits payment to 50% of the amount that would have been allowed if personally performed by a anesthesiologist or non-supervised CRNA.
QX: This modifier is used to bill a service performed by a Certified Registered Nurse Anesthetist (CRNA) under the medical direction by a Anesthesiologist.
- This modifier limits payment to 50% of the amount that would have been allowed if personally performed by an anesthesiologist or non-supervised CRNA.
QY: Anesthesiologist medically directs one CRNA.
- This modifier limits payment to anesthesiologist and CRNA to 50% of the amount that would have been allowed if personally performed by anesthesiologist.
QZ: CRNA service without medical direction by a anesthesiologist
- This modifier has no effect on payment and the allowed amount is what would have been allowed if personally performed by an anesthesiologist.
The anesthesia modifiers above are pricing modifiers and must be listed in the first Modifier field to ensure correct reimbursement.
The modifiers below: QS, G8 and G9 modifiers are informational only and do not affect payment. Informational modifiers must be used in the second modifier field, in conjunction with a pricing anesthesia modifier in the first modifier field.
QS: Monitored anesthesia care (MAC); Use in addition to P modifiers for anesthesia codes.
G8: Report modifier G8 instead of QS if the anesthesia provider monitored anesthesia care for deep complex, complicated, or markedly invasive surgical procedures (MAC).
G9: (MAC) Use if the anesthesia provider provides monitored anesthesia for a patient who has a history of severe cardiopulmonary condition and may be used in lieu of modifier QS.
Example of a Medically Directed Case
A 67-year-old Medicare beneficiary undergoes a total hip arthroplasty (total hip replacement)
- CPT® code 27130: Arthroplasty, acetabular and proximal femoral prosthetic replacement (total hip arthroplasty), with or without autograft or allograft.
- The ASA CROSSWALK® links this procedure to the Anesthesia Code 01214, Anesthesia for open procedures involving hip joint; total hip arthroplasty.
- This case is being performed by a CRNA
- Who is being Medically Directed by an Anesthesiologist
- The Anesthesiologist is also Medically Directing 2 other cases concurrently.
- The reported anesthesia time is 129 minutes.
- A 15-minute time unit setup
- Calculated to one decimal point
- 129 minutes is converted to 8.6 Time units (129/15=8.6)
- Anesthesia time is reported in actual minutes on Claims.
Medicare Payment Calculation for an Anesthesia Service
- The base units assigned to the anesthesia code plus the time units as determined from the time reported on the claim. (8+8.6=16.6)
- Multiply the sum by a conversion factor which is the dollar per unit amount.
- For CY 2023, the Medicare Anesthesia Conversion factor is $20.6097 per Unit.
- Modifier QK (Anesthesiologist)
- Modifier QX (CRNA)
(Base Units + Time Units) x Conversion Factor: (8 base units + 8.6 time units) x $20.6097/unit = $342.12 (Approved Amount)
- If this was being done by an Anesthesiologist only, the Payment to the Provider would be $342.12.
- Because it was Medically Directed by an Anesthesiologist (as indicated by the Modifiers), each provider only receives $171.06 (50% of the Approved Amount)
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