CCSD code B3440 – Microdochotomy (breast duct incision)

Key takeaways

CCSD Code B3440 covers microdochotomy, a surgical incision into a breast (mammary) duct that opens the duct without removing it.

B3440 sits in Chapter 7 (Breast) of the CCSD schedule, and Freedom Health’s March 2026 schedule bands it Intermediate.

If the surgeon removes the duct, the procedure is microdochectomy and the correct code is B3593, not B3440.

B3440 cannot be billed with B2820, B3310, B3593 or B3595 at the same operation.

Most UK private medical insurers expect pre-authorisation for elective breast surgery, so confirm it before the operation date.

CCSD Code B3440: what microdochotomy covers

CCSD Code B3440 is the CCSD code for microdochotomy, a surgical incision into a breast duct, also called a mammary or lactiferous duct. The surgeon opens and explores the duct but does not remove it. The Clinical Coding and Schedule Development (CCSD) Group maintains the schedule that UK private medical insurers use to identify procedures on a claim.

B3440 sits in Chapter 7 (Breast) of the CCSD schedule, in the Other section alongside drainage of breast abscess. Freedom Health’s CCSD-based schedule (March 2026) lists it at Intermediate complexity. Complexity bands, fee categories and benefit maximums differ between insurers, so check the current band in each payer’s own schedule.

The coding decision for breast duct surgery comes down to one question: was duct tissue removed? An incision that leaves the duct in place is B3440. Excising the duct is microdochectomy, which has its own code, B3593. The descriptor does not mention laterality, so record which breast was treated on every claim.

Clinical indications for microdochotomy

Surgeons choose microdochotomy when a problem is confined to a duct and opening it is enough. The operative note should name the indication the surgeon identified and treated. Typical presentations include:

• Nipple discharge traced to one duct, where the surgeon opens the duct to explore its source
• A blocked or dilated duct behind the nipple that needs opening rather than removal
• Localised duct inflammation near the nipple, where the surgeon lays the affected duct open

Single-duct nipple discharge is often treated by removing the duct so it can be examined under a microscope. That operation is microdochectomy, coded B3593, even when the indication is the same as for B3440.

Where B3440 sits among the CCSD breast codes

The table below lists B3440 with the four codes the CCSD schedule names as unacceptable combinations with it. Each describes a different breast operation, and none can share a claim with B3440 for the same operation. Excision of a breast lump or fibroadenoma has its own code too, B2800, but it is not on that list.

Coders looking for a tear duct procedure need a different chapter entirely. Lacrimal operations use C-codes in the eye chapter, such as C2510 to C2550. Our guide to Bupa CCSD codes covers payer-specific schedule details, and you should check the current schedule version before quoting a fee. For codes in other chapters, browse our CCSD codes reference.

B3440 vs adjacent breast codes: the incision-or-excision test

Most B3440 coding errors come from an operative note that does not say clearly what happened to the duct. Match the documented procedure to the code before the claim leaves the practice.

If the note describes both an incision and an excision, code the excision and drop B3440. Ask the surgeon to clarify any note that leaves the question open, rather than choosing the code yourself. The diagram below puts the test and the four blocked combinations in one view.

Documentation required to support a B3440 claim

UK private medical insurers review B3440 claims against the clinical record. Incomplete documentation is the fastest route to a query or a denial. The operative note for microdochotomy should include the following elements.

• Confirmed indication: the presenting problem, such as nipple discharge or a blocked duct, with the clinical or imaging findings behind it
• Laterality: left or right breast, and the duct position if the surgeon recorded it
• Procedure performed: an explicit statement that the duct was incised and left in place, not excised
• Specimens: whether any tissue went to histology, since a duct specimen will prompt an insurer query about excision
• Surgeon and date: the operating surgeon’s name, GMC number and date of operation
• Pre-authorisation reference: the insurer’s reference number, matching the code and side that were approved

Pabau, the practice management platform we build, lets a practice set up structured operative note templates. Each template prompts for the fields above before the surgeon signs the note off.

Pre-authorisation requirements for microdochotomy

Most UK private medical insurers treat elective breast surgery as needing pre-authorisation before it goes ahead. Requirements vary by insurer and policy year, so verify the specific policy at the time of booking.

• Bupa: pre-authorisation is typically required. Check the code in the Bupa code search portal and supply the consultant letter, diagnosis and proposed CCSD code
• AXA Health: pre-authorisation is usually needed for elective surgery, so confirm the process with AXA Health before booking
• Aviva: pre-authorisation is required; see the Aviva fee schedule and procedure guidelines for supporting information
• Vitality and WPA: pre-authorisation is typically required, so contact the insurer’s provider helpline before booking

Record the reference number in the patient file as soon as it is issued. If the surgeon later expects to excise the duct, ask the insurer to update the approval to B3593 before the operation.

Billing microdochotomy: can CCSD Code B3440 be billed with other codes?

No, not with the four codes the CCSD schedule lists as unacceptable combinations for B3440 at the same operation. Insurers reject the claim line when one of them appears alongside it.

• B3440 + B3593 (microdochectomy or mammodochectomy): not billable together. Removing the duct supersedes opening it, so bill B3593 alone
• B3440 + B3595 (excision of mammary fistula): not billable together. Excising the fistula tract is the operation to report
• B3440 + B3310 (drainage of breast abscess): not billable together. Report the code that matches the main operation in the note
• B3440 + B2820 (wide local excision of breast): not billable together. A wide local excision already covers the tissue around the duct
• Both breasts at one sitting: the descriptor does not mention laterality. Check the insurer’s bilateral rules and the CCSD Technical Guide before submitting

For any other combination, check the insurer’s own rules before submitting. A pre-submission query to the provider helpline takes less time than a denial and resubmission cycle.

Common reasons B3440 claims are denied and how to resolve them

The table below maps the usual reasons a B3440 claim comes back to the fix that gets it paid on resubmission.

How Pabau supports CCSD billing for breast duct surgery

Billing B3440 accurately across several UK private payers means tracking pre-authorisation references, keeping operative documentation precise and sending the right CCSD code first time. Pabau brings those steps into one patient record for private breast surgery practices.

• Structured clinical notes: digital forms prompt the surgeon for side, indication and whether the duct was incised or excised
• Pre-authorisation tracking: the insurer’s reference is recorded in the patient record alongside the invoice, so it stays with the claim
• Insurer invoicing: billing staff add the CCSD code and reference to the insurer invoice, and supporting letters are generated from the same record

Pabau’s private practice claims management then sends the claim to Healthcode and tracks it through to payment. The result is fewer queries about missing references or unclear notes, and less time spent on resubmissions.

Get breast surgery claims right first time

Pabau keeps the operative note, pre-authorisation reference and insurer invoice together for UK private breast surgery practices, so B3440 claims reach Healthcode complete.

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Conclusion

B3440 is a narrow code, and the line around it is the duct itself. If the surgeon opened it and left it in place, B3440 is right. If any duct tissue came out, B3593 is the code, and B3440 drops off the claim.

Fix that question at the operative note, not at the invoice. A note that names the side and says incised or excised protects the claim from the wrong-code and laterality denials in the table above. Book a demo to see how Pabau keeps operative notes, pre-authorisation and insurer claims together for breast surgery practices.

Continue your research

Billing a Bupa patient? Bupa CCSD codes explains how Bupa applies the CCSD schedule to private claims.

Coding a lump excision instead? CCSD code B2800 covers excision of a breast lump or fibroadenoma.

Was the lesion localised first? CCSD code B2880 covers excision biopsy of a breast lesion after localisation.

Working on major breast surgery claims? CCSD code B2743 is the billing guide for modified radical mastectomy.

Want fewer claim errors across the practice? Private practice claims management shows how Pabau sends claims and tracks them through to payment.

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