QZ is the anesthesia billing modifier for a CRNA service without medical direction by a physician. Medicare pays QZ claims at 100 percent of the anesthesia fee schedule amount, the same amount an anesthesiologist working alone would receive.
If you practice independently, or your group bills non-medically directed cases, QZ is the modifier on most of your claims. Here is exactly what it means, how it pays, and where people get it wrong.
Key points
- QZ means a CRNA billed with no physician billing medical direction.
- Medicare pays QZ at 100 percent of the fee schedule, same as AA.
- QZ is billed in all 50 states, opt-out or not.
- One case, one model: never QZ and QX on the same case.
What QZ actually says
Every anesthesia claim carries a modifier that tells the payer the care model:
| Modifier | Meaning |
|---|---|
| AA | Anesthesiologist personally performed |
| QY | One anesthesiologist medically directing one CRNA |
| QK | Anesthesiologist medically directing 2 to 4 concurrent cases |
| QX | CRNA with medical direction by a physician |
| QZ | CRNA without medical direction by a physician |
| AD | Physician supervising more than 4 concurrent procedures |
QZ says: a CRNA provided the anesthesia, and no physician met the requirements for medical direction on this case. That is a billing statement, not a clinical one. A surgeon was still in the room operating, and in non opt-out states a physician supervision condition of participation may still apply at the facility level. QZ is about whether the seven medical direction steps were performed and billed, not about whether any physician was in the building.
For the full breakdown of direction vs supervision, see medical direction vs medical supervision.
How Medicare pays QZ
Under the Medicare Claims Processing Manual, payment for the service of a CRNA who is not medically directed is 100 percent of the anesthesia fee schedule amount. The claim is priced the usual way: (base units + time units) x the anesthesia conversion factor, which is $20.4976 nationally for 2026, adjusted by locality.
Two things follow from that:
- A QZ case pays the same total as an AA case for the same procedure and time. Medicare does not discount CRNA care.
- All of the payment goes to the CRNA (or the CRNA's employer or group, if billing rights are reassigned). Nothing is split with a physician, because no physician billed direction.
Compare that to medical direction, where the same total is split 50/50 between the directing physician (QY or QK) and the CRNA (QX). See how CRNAs are paid by Medicare for the bigger picture.
When QZ applies
Use QZ when a CRNA provides the anesthesia service and no anesthesiologist is billing medical direction for the case. Common situations:
- Independent CRNA practice, including solo 1099 CRNAs and all-CRNA groups
- Rural and critical access hospitals without anesthesiologists on staff
- Care team settings where the anesthesiologist did not complete or document all seven medical direction steps, so the group bills the case QZ instead of QK/QX
That last one matters. Some anesthesiologist-CRNA groups deliberately bill QZ even with physicians present, because it removes the burden of documenting the seven TEFRA steps on every case. That is legal and common. What is not allowed is billing the same case both ways.
Common QZ mistakes
- Billing QZ and QK/QY on the same case. One case, one care model. If the physician bills direction, the CRNA bills QX, not QZ.
- Assuming QZ is illegal in non opt-out states. It is not. Opt-out affects the facility supervision condition for Medicare participation, not the QZ payment rule. CRNAs bill QZ in all 50 states.
- Wrong payer rules. Some Medicaid programs and commercial payers pay QZ at less than 100 percent or have their own modifier rules. Check each contract instead of assuming Medicare's rule carries over.
- Concurrency conflicts. A CRNA cannot bill two overlapping QZ cases for the same minutes. Overlapping times are an audit flag.
- Missing enrollment. QZ payment goes to the CRNA's own billing, so the CRNA must be enrolled with Medicare and credentialed with commercial payers before the date of service.
Why QZ matters for your career
QZ is the financial backbone of independent CRNA practice. Because it pays the full fee schedule amount, an all-CRNA group collects the same anesthesia professional fees as a physician group for the same work. That is what makes starting a CRNA group financially viable, and it is a core number in the group revenue calculator.
Questions
Does QZ pay less than AA?
No. Medicare pays both at 100 percent of the anesthesia fee schedule amount. Some commercial and Medicaid payers differ, so check each contract.
Can QZ be billed when an anesthesiologist is in the facility?
Yes, as long as that physician is not billing medical direction for the case. QZ describes the billing model, not physician proximity.
Does QZ require an opt-out state?
No. Opt-out removes the federal physician supervision condition of participation for facilities. QZ billing and its 100 percent payment apply nationwide.
Who gets the money on a QZ claim?
The enrolled billing entity, which is the CRNA individually or the group the CRNA has reassigned benefits to.