Crystal's Coder Hub⚕️ Modifier QY - Anesthesiologist Directing One Certified Registered Nurse Anesthetist
Quick Reference
Descriptor: Anesthesiologist directing one certified registered nurse anesthetist 1
Global Period: Follows the primary anesthesia procedure code 2
Provider Type: Anesthesiologist (MD/DO) directing a CRNA 3
Reimbursement: Medicare pays 50% of the allowed anesthesia amount to the anesthesiologist 4
NCCI Status: Subject to medical direction rules (Tefra regulations) 5
Approach: Appended to Anesthesia CPT® codes (00100-01999)
📋 Code Description & Clinical Context
Modifier -QY is a HCPCS Level II modifier used to identify when an anesthesiologist is medically directing one certified registered nurse anesthetist (CRNA) during a surgical procedure 1. This modifier is part of the “-AA, -QK, -QY, -QX, -QZ” series used to define the relationship between anesthesia providers and determine reimbursement splits under Medicare and many commercial plans 3.
Key Usage Indications:
- An anesthesiologist is medically directing a single CRNA
- The anesthesiologist performs specific medical direction tasks (pre-op exam, prescription, participation in critical portions, monitoring, post-op care)
- The CRNA performs the hands-on administration of anesthesia
- Documentation supports the medical direction relationship per Tefra regulations
Medical Direction Requirements
To bill -QY, the anesthesiologist must meet the “medical direction” criteria: performing pre-anesthetic examination, prescribing the anesthesia plan, personally participating in critical portions, ensuring qualified individuals perform other tasks, monitoring anesthesia administration, and providing indicated post-anesthesia care 6.
🌲 Code Hierarchy / Context
HCPCS Level II Modifiers
└─ Anesthesia Modifiers
├─ -AA Anesthesia services performed personally by anesthesiologist
├─ -QK Medical direction of two, three, or four CRNAs
├─ -QY Anesthesiologist directing one certified registered nurse anesthetist ← THIS CODE
├─ -QX CRNA service with medical direction by a physician
└─ -QZ CRNA service without medical direction by a physician
Parent Category: Anesthesia Modifiers 7
Related Modifiers: -AA, -QK, -QX, -QZ, -ad (Supervision >4 cases)
Primary Code Dependency: Must be appended to a valid Anesthesia CPT® code (e.g., 00100, 00300)
💰 Reimbursement & Valuation
| Component | Rate | Notes |
|---|---|---|
| Base Rate | 100% | Based on the allowed amount for the Anesthesia CPT® code 4 |
| Anesthesiologist Share | 50% | Standard reimbursement rate for medical direction of one CRNA 4 |
| CRNA Share | 50% | CRNA bills separately with modifier -QX for the remaining 50% 4 |
| Final -QY Rate | 50% | Of the total allowed anesthesia fee schedule amount 4 |
| Global Period | Same as Primary | Anesthesia services are paid per unit/time; no global period in surgical sense 2 |
Assistant Surgeon Payable: N/A (Anesthesia Direction)
- Medicare Status Indicator: Depends on primary anesthesia code coverage 7
- If medical direction requirements are not met, reimbursement may be denied or reduced
- Commercial payers may vary (some follow Medicare 50/50 split, others have contracted rates)
Medicare Payment Estimate: Varies by anesthesia base units + time units × Conversion Factor × 50% 4
🚫 Includes / Excludes & NCCI Guidance
✅ Includes
- Medical direction of a single CRNA by an anesthesiologist
- Pre-operative anesthesia evaluation by the anesthesiologist
- Participation in critical portions of the anesthesia plan
- Post-operative anesthesia care by the anesthesiologist
- Monitoring of the CRNA’s administration
❌ Excludes / Bundled Per NCCI
- Personal performance of anesthesia (use -AA if anesthesiologist does it all) 3
- Medical direction of 2-4 CRNAs (use -QK) 3
- Medical supervision of >4 concurrent procedures (use -ad) 3
- CRNA services without medical direction (CRNA uses -QZ) 3
- Services not meeting Tefra medical direction criteria (may be denied) 6
Tefra Regulations Critical Note
🏥 MS-DRG Assignment (Inpatient Facility)
Modifier -QY does not directly impact MS-DRG assignment, as DRGs are based on the primary surgical procedure and diagnoses. It affects physician reimbursement under Medicare Part B.
| Scenario | Impact | Description |
|---|---|---|
| Anesthesia medically directed | Payment Split | Anesthesiologist paid 50%, CRNA paid 50% 4 |
| Anesthesia personally performed | Full Payment | Anesthesiologist bills -AA for 100% 4 |
| Inpatient Status | Part B Billing | Anesthesia services billed on CMS-1500/837P 8 |
Note
Facility reimbursement (Part A) is not affected by modifier -QY; this modifier is for professional fee billing only 8.
🏷️ Common ICD-10-CM Diagnosis Codes
Modifier -QY does not change diagnosis coding requirements. Diagnosis codes must support the medical necessity of the primary surgical procedure and anesthesia.
Primary Diagnosis Options (Dependent on Procedure)
| ICD-10-CM Code | Description | HCC Status* |
|---|---|---|
| K80.20 | Calculus of gallbladder without cholecystitis | ❌ Not HCC |
| M17.11 | Unilateral primary osteoarthritis, right knee | ❌ Not HCC |
| C67.9 | Malignant neoplasm of bladder | ✅ HCC (Cancer) |
| Z40.01 | Encounter for prophylactic surgery for malignant neoplasm | ✅ HCC (History of Cancer) |
| I10 | Essential (primary) hypertension | ✅ HCC (Cardiovascular) |
* HCC Status: Hierarchical Condition Category mapping for Medicare Advantage risk adjustment. Diagnosis codes determine HCC status, not the modifier. Modifier -QY has no impact on risk adjustment scores 910.
Supporting/Comorbid Codes (Document When Applicable)
- N18.30 Chronic kidney disease, stage 3 unspecified (HCC applicable)
- E11.9 Type 2 diabetes mellitus without complications (HCC applicable)
- J44.9 Chronic obstructive pulmonary disease, unspecified (HCC applicable)
✏️ Modifiers Guidance
| Modifier | Use Case for -QY | Payable? |
|---|---|---|
| -AA | Anesthesia performed personally by anesthesiologist | ❌ Do not use with -QY |
| -QK | Medical direction of 2-4 CRNAs | ❌ Do not use with -QY |
| -QX | CRNA service with medical direction | ✅ Used by CRNA when anesthesiologist bills -QY |
| -QZ | CRNA service without medical direction | ❌ Mutually exclusive with -QY relationship |
| -ad | Medical supervision >4 procedures | ❌ Do not use with -QY |
| -47 | Anesthesia by Surgeon | ❌ Mutually exclusive |
| -23 | Unusual Anesthesia | ✅ Can be used with -QY if unusual circumstances exist |
📝 Coding Examples
✅ Example 1: Anesthesiologist Directing One CRNA
Scenario: Patient undergoes knee arthroscopy. Anesthesiologist medically directs one CRNA. Anesthesiologist performs pre-op exam, participates in induction, monitors, and provides post-op care.
Report:
❌ Example 2: Anesthesiologist Directing Two CRNAs
Scenario: Anesthesiologist directs two CRNAs in two different ORs simultaneously. Bills -QY.
Report: 00402--QY
Rationale: Incorrect. When directing 2-4 CRNAs, modifier -QK must be used. -QY is for one CRNA only 3.
⚠️ Example 3: Personal Performance
Scenario: Anesthesiologist performs all anesthesia services personally without CRNA. Bills -QY.
Report: 00402--QY
Rationale: Incorrect. If personally performed, modifier -AA should be used for 100% reimbursement 3.
✅ Example 4: Unusual Anesthesia with Direction
Scenario: Patient has severe cardiac disease requiring unusual anesthesia techniques. Anesthesiologist directs one CRNA.
Report:
🔍 Documentation Essentials for Support
To support modifier -QY and mitigate audit risk, anesthesia documentation should include:
- Medical Direction Tasks: Document the 7 steps of medical direction (pre-op, plan, critical portions, etc.) 6.
- Concurrency: Clearly state how many CRNAs are being directed concurrently (must be one for -QY).
- Presence: Anesthesiologist must be physically present during critical portions.
- Availability: Anesthesiologist must be immediately available for emergencies.
- Signatures: Both anesthesiologist and CRNA must sign the anesthesia record.
- Time: Document start and stop times for anesthesia care.
Medical Record Language
Ensure the anesthesia record states: “Anesthesiologist medically directed one CRNA. Pre-operative evaluation performed. Participated in induction and emergence. Monitored throughout procedure.”
⚠️ Common Pitfalls & Audit Risks
| Pitfall | Consequence | Prevention |
|---|---|---|
| Using -QY for >1 CRNA | Claim denial or recoupment | Use -QK for 2-4 CRNAs 3 |
| Failing to meet Tefra criteria | Payment denial | Ensure all 7 medical direction steps are documented 6 |
| Using -QY for personal performance | Underpayment | Use -AA if anesthesiologist performs all services 3 |
| Missing CRNA modifier -QX | Claim mismatch | CRNA should bill -QX when anesthesiologist bills -QY 11 |
| Inadequate time documentation | Payment reduction | Document exact anesthesia time units 11 |
🔗 Related Codes & Crosswalks
| Code Type | Code | Relationship to -QY |
|---|---|---|
| HCPCS Modifier | -AA | Anesthesia services performed personally by anesthesiologist |
| HCPCS Modifier | -QK | Medical direction of two, three, or four CRNAs |
| HCPCS Modifier | -QX | CRNA service with medical direction by a physician |
| HCPCS Modifier | -QZ | CRNA service without medical direction by a physician |
| HCPCS Modifier | -ad | Medical supervision by a physician; more than four concurrent anesthesia procedures |
| CPT® | 00100-01999 | Anesthesia Procedure Codes |
| CMS Form | CMS-1500 | Professional claim form where -QY is reported |
1 CMS HCPCS Level II Modifier Definitions
2 CMS Global Surgery Factsheet
3 Medicare Claims Processing Manual Ch. 12
4 CMS Medicare Physician Fee Schedule 2024
5 CMS NCCI Policy Manual 2024
6 CMS Tefra Regulations Guidance
7 NIH VSAC HCPCS Hierarchy
8 Medicare Claims Processing Manual Ch. 1
9 CMS-HCC Model V28 Documentation
10 Find-A-Code HCC Mapping Tool
11 AAPC Coding Modifier Guidelines
12 ASA Guidelines for Medical Direction