< Billing codes

Billing code

E546A

Axillary node dissection add-on

Add for axillary node dissection up to the axillary vein, done with a partial mastectomy or oncoplastic breast surgery.

Watch for: Only with R111, R102, R158 or R159; Z427 sentinel node biopsy is extra only when frozen section shows micrometastases.

Code

E546A

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

Add-on for axillary node dissection up to the axillary vein, done with a partial mastectomy or oncoplastic breast surgery.

What it covers

E546 is axillary node dissection up to the level of the axillary vein, added to R111 partial mastectomy or wedge resection (M25).

It is also listed as payable with the oncoplastic breast-conserving procedures R102, R158 and R159 (M26).

Billing rules

• Only with R111, R102, R158 or R159 (M25, M26).
• Sentinel node biopsy Z427 is payable in addition to E546 only when a frozen section report shows micrometastases (M25).
• Limited axillary node sampling is a different add-on, E505 (M25).
• E546 is on the list of procedures that take the E676 morbid obesity premium (SP6).
• Marked #: premises, equipment, supplies and staff for the procedure are not included in the fee (SP1).

Often billed with

• R111 partial mastectomy (M25).
• E525 after localization with mammographic wire or radioactive seeds (M25).

Common rejections

• ADF: OHIP describes this as 'Corresponding procedure invalid, omitted or paid at zero': E546 was billed without a payable R111, R102, R158 or R159 for the same patient and day.

Related codes: R111, E505, Z427, R102, R158, R159, E525

Source: Schedule of Benefits (July 1, 2026), Integumentary System Surgical Procedures, Operations of the Breast, page M25.

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