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Billing code

Z427A — Sentinel Node Biopsy, Per Draining Basin

Sentinel lymph node biopsy

Bill for sentinel node biopsy, once per draining basin biopsied.

Watch for: Not payable with E505, and payable with E546 only when the frozen section shows micrometastases.

Code

Z427A

Description

Sentinel Node Biopsy, Per Draining Basin

FHO+ basket

Not in the FHO+ base rate basket (Schedule 2 or 2B).

Effective date

Apr 1, 2026

Termination date

No end date

Explanation

Updated October 26, 2026

Sentinel lymph node biopsy, billed per draining basin. Not payable with E505, and with E546 only when frozen section shows micrometastases.

What it covers

Z427 is sentinel node biopsy, billed per draining basin, under Lymph Channels in the Haematic and Lymphatic Surgical Procedures section (R2). The breast surgery listings refer to Z427 for sentinel node biopsy (M25).

As a Z code it is an independent operative procedure (IOP), payable in addition to an assessment (GP4). The Schedule lists 6 assistant units and 8 anaesthesia units for it (R2).

Billing rules

• One Z427 per draining basin biopsied (R2).
• E505 (limited axillary node sampling) is not payable in addition to Z427 (M25).
• Z427 is payable in addition to E546 (axillary node dissection) only when a frozen section report demonstrates micrometastases (M25).
• If you did the major pre-operative visit in the previous 12 months, only a partial assessment (specialist) or minor assessment (GP/FP) is payable before the IOP that day; if the major pre-operative visit is that same day, no other consultation or assessment before the IOP is payable (SP4).
• Several basins: when multiple or bilateral IOPs are done at the same time by the same physician, each procedural fee is claimed in full, with pre- and post-operative care counted once (SP4). With a non-IOP procedure under the same anaesthesia, the general rule is full benefit for the major procedure and 85% for the others, unless the Schedule states otherwise (SP2).
• Z427 is on the E676 list: E676A (+25% surgeon) and E676B (+6 assistant units) are payable once per patient per physician for a morbidly obese patient (BMI over 40, recorded in the chart) when the SP6 criteria are met, including general anaesthesia; not under local anaesthesia (SP6, SP7).
• Marked # in the Schedule: premises, equipment, supplies and staff for the procedure itself are not part of the physician's fee (SP1).

Often billed with

• A034 partial assessment (General Surgery) at the visit before the procedure, within the IOP rules (A107, SP4).
• R102 level 1 oncoplastic lumpectomy, R111 partial mastectomy or R108 simple mastectomy for breast cancer (M25, M26).
• E525 when the breast excision follows wire or radioactive seed localization, added to R107, R111, R102, R158 or R159 (M25, M26).

Related codes: E505, E546, R111, R102, R108, Z411, R914, E525

Source: Schedule of Benefits (July 1, 2026), Haematic and Lymphatic Surgical Procedures, Lymph Channels, page R2; Integumentary System Surgical Procedures, Operations of the Breast, page M25; Surgical Preamble SP2, SP4, SP6

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