AnesthesiaMedium audit riskHCPCS

HCPCS Modifier QY

Medical Direction of One Certified Registered Nurse Anesthetist (CRNA) by an Anesthesiologist

Source: AMA CPT / CMS HCPCS Level II definitions. Maintained by the D3rx Clinical Billing Team.

What modifier QY means

Modifier QY is reported by an anesthesiologist who medically directs a single CRNA (or qualified non-physician anesthetist) in one case — the one-on-one version of QK. It identifies the directing physician's portion of a medically directed case and pairs with the CRNA's QX, with payment commonly split 50/50. The seven medical-direction steps must be met.

When to use it

An anesthesiologist medically directs exactly one CRNA/AA for a single anesthesia case and satisfies all seven medical-direction requirements.

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Documentation checklist

The record should support every item below before you append modifier QY.

  • All seven medical-direction steps performed by the anesthesiologist
  • That exactly one CRNA/qualified individual was directed (one-on-one)
  • The paired QX line from the CRNA
  • Times documenting the physician's presence at the key portions (induction/emergence)

Do NOT use modifier QY when

  • Directing two to four concurrent cases — use QK
  • Personally performing the anesthetic — use AA
  • The CRNA worked without direction — the CRNA uses QZ (no physician modifier)
  • Any of the seven medical-direction steps was not met

Common denial reasons

  • Documentation doesn't support all seven medical-direction steps
  • QY billed when more than one case was actually directed (should be QK)
  • The QY and the CRNA's QX don't reconcile across the paired claims

Denial codes you may see with modifier QY

CO-4CO-151CO-59

How to appeal a modifier QY denial

Submit documentation of all seven medical-direction steps and that only one CRNA was directed, with the matching QX line. If denied for concurrency, show a single directed case (QY, not QK); if denied for direction, map the record to each of the seven steps.

Payer notes

QY is one-on-one medical direction (a single CRNA), distinct from QK (two to four concurrent). The directing physician bills QY and the CRNA bills QX, splitting the payment. As with QK, the seven medical-direction steps must be met and documented.

Related & commonly confused modifiers

Modifier QKModifier QXModifier QZModifier QS

Where modifier QY is used

  • Anesthesia services (00100-01999)
  • One-on-one care-team anesthesia
  • Medically-directed single-CRNA cases

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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.