Billing code
G166A — Hydrogen breath test – professional component
Hydrogen breath test, interpretation
Bill G166 for the professional component (supervision and interpretation) of a hydrogen breath test; the technical component is G167.
Watch for: You must personally interpret the results to bill the professional component.
| Provider | Specialist | Assistant | Anaesthetist | Non-anaesthetist |
|---|---|---|---|---|
| $10.45 | $0.00 | $0.00 | $0.00 | $0.00 |
- Code
- G166A
- Description
- Hydrogen breath test – professional component
- FHO+ basket
- Not in the FHO+ base rate basket (Schedule 2 or 2B).
- Effective date
- Apr 1, 2025
- Termination date
- No end date
Explanation
Updated October 26, 2026
The professional component (supervision and interpretation) of a hydrogen breath test. The technical component is G167.
What it covers
G166 is the professional component of a hydrogen breath test; the technical component is G167 (J45).
Billing rules
- Professional component: supervision, any associated clinical procedure, monitoring and interpretation; interpretation must be done personally by the billing physician (J1).
- The technical component (G167) covers performing the test, records and the written report (J2, J45).
- Diagnostic codes split into components: B = technical, C = professional (GP11).
Often billed with
- G167 technical component, when you also perform the test (J45).
Related codes: G167, G352, G357, G350
Source: Schedule of Benefits (July 1, 2026), Diagnostic and Therapeutic Procedures, Gastroenterology, page J45.
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