HCPCS Modifier QK
Medical Direction of Two, Three, or Four Concurrent Anesthesia Procedures Involving Qualified Individuals
Source: AMA CPT / CMS HCPCS Level II definitions. Maintained by the D3rx Clinical Billing Team.
What modifier QK means
Modifier QK is reported by the anesthesiologist who medically directs two, three, or four concurrent anesthesia procedures performed by qualified individuals (CRNAs, anesthesiologist assistants, or residents). It identifies the directing physician's portion of a medically directed case; payment is split, with the physician (QK) and the non-physician anesthetist (QX) each typically receiving 50%. Medical direction requires meeting all seven of Medicare's medical-direction steps.
When to use it
An anesthesiologist concurrently medically directs two to four anesthesia cases furnished by qualified individuals and satisfies all seven medical-direction requirements.
Documentation checklist
The record should support every item below before you append modifier QK.
- All seven medical-direction steps (pre-anesthetic exam/evaluation; prescribing the anesthesia plan; personally participating in the most demanding portions including induction and emergence; ensuring a qualified individual performs the remaining procedures; monitoring at frequent intervals; remaining physically present and available; providing post-anesthesia care)
- The number of concurrent cases (no more than four)
- The qualified individuals (CRNA/AA/resident) directed in each case
- Times documenting the physician's presence at the key portions
Do NOT use modifier QK when
- Directing only ONE CRNA/qualified individual — use QY
- Personally performing the anesthetic — use AA
- Directing more than four concurrent procedures — this is medical supervision (modifier AD)
- Any of the seven medical-direction steps was not met
Common denial reasons
- Documentation doesn't support all seven medical-direction steps
- More than four concurrent procedures were directed (should be AD)
- The directing physician's QK and the CRNA's QX don't match across the paired claims
- Anesthesia time/units inconsistent between the directed lines
How to appeal a modifier QK denial
Submit documentation establishing all seven medical-direction steps and that no more than four concurrent cases were directed, along with the matching QX line from the CRNA. If denied for concurrency, show the case count was four or fewer; if denied for direction, map the record to each of the seven steps.
Payer notes
QK is the DIRECTING physician's modifier in a medically directed case; the CRNA/AA reports QX, and together they reflect the split (commonly 50/50) payment. Directing more than four concurrent cases shifts to medical supervision (AD). The seven medical-direction steps must be met and documented — this is a longstanding audit focus.
Related & commonly confused modifiers
Where modifier QK is used
- Anesthesia services (00100-01999)
- Concurrent operating-room cases under medical direction
- Care-team anesthesia (physician + CRNA/AA)
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Medical billing disclaimer
Modifier definitions follow standard AMA CPT and CMS HCPCS Level II guidance and are for educational reference. Payer policies, billing formats, and coverage rules vary and change. Always verify the current rule with the specific payer before submitting. D3rx is not responsible for claim outcomes.