CCSD code A6400 – Peripheral nerve repair

Key takeaways

CCSD Code A6400 covers direct suture repair of a severed or disrupted peripheral nerve, by epineural or fascicular neurorrhaphy.

Nerve grafting and neurolysis fall outside A6400 and carry their own codes. Mixing up A6400 and A6810 is the most common coding error here.

Most UK private insurers expect pre-authorization before elective nerve repair, and a missing authorization reference is a leading cause of denial.

The operative note must name the nerve, the repair technique and the intraoperative findings to meet insurer documentation requirements.

CCSD Code A6400: What the procedure covers

CCSD Code A6400 covers the surgical repair of a peripheral nerve. It restores continuity to a nerve trunk that has been severed, lacerated or otherwise disrupted. The procedure is neurorrhaphy, in which the surgeon brings the nerve ends together and sutures them so axons can regenerate across the repair site.

A6400 applies across a wide range of peripheral nerves. The nerves most often repaired under it are the digital nerves of the hand and the ulnar, median and radial nerves. The common peroneal nerve in the leg is another. The code isn’t tied to one anatomical site. It applies wherever a named peripheral nerve needs direct surgical repair.

Two primary repair techniques fall within the scope of A6400.

Both techniques are performed under loupe magnification or an operating microscope. The use of microsurgical instruments, nerve clamps, or fibrin glue as an adjunct to suture does not change the code. A6400 covers the repair itself, including wound preparation, nerve-end trimming to healthy fascicles, and closure of the surgical access incision.

What is excluded from A6400?

Three procedure categories are explicitly outside the scope of A6400 and must be coded separately when they are performed.

• Nerve grafting. When the nerve ends are too far apart for a tension-free direct repair, the surgeon bridges the defect with a nerve graft. Common options are a sural nerve graft or a cable graft from another sensory donor nerve. Nerve grafting has its own CCSD code, so billing A6400 for a grafted nerve is an unbundling error that leads to denial or audit. Verify the applicable graft code against the current CCSD schedule.
• Neurolysis and transposition (A6810). A6810 covers releasing a nerve from surrounding scar tissue or a compressive structure without repairing the nerve itself. Ulnar nerve transposition and internal neurolysis for scar entrapment fall under it. Carpal tunnel release is excluded from A6810 and coded on its own. Using A6400 when the nerve was only released is the single most common coding error for this procedure group.
• Intraoperative nerve monitoring (IONM). Electrophysiological monitoring performed during the repair, whether by a separate neurophysiologist or via integrated monitoring equipment, is coded and billed separately. It is not bundled into A6400.

When a surgeon performs both repair and neurolysis in one operative episode, check the current insurer schedule. It says whether both codes may be submitted or one subsumes the other. Policies vary between insurers and are updated periodically.

A6400 vs A6810: Key differences for coders

A6400 and A6810 are the two most frequently confused codes in the CCSD peripheral nerve section. The clinical distinction is clear. A6400 requires a structural repair of the nerve by suture. A6810 applies when the nerve is released from compression or internal scarring without suture repair.

The operative report is the deciding document. If the note describes lysis of adhesions around the ulnar nerve but no suture repair, A6810 is correct. If it describes transection of the nerve and end-to-end suture, A6400 is correct.

When both are performed on different nerves, check insurer rules on same-session dual coding. The diagram below maps each finding in the note to its code.

Related CCSD codes alongside A6400

Several codes commonly appear in the same operative episode or patient pathway as A6400. Knowing when each is appropriate prevents both under-coding and unbundling errors.

When A6400 goes in alongside anesthetic or monitoring codes, each practitioner files their own claim. Bundling separate practitioners’ fees into one submission is a common administrative error that triggers insurer queries. The neighboring peripheral nerve codes, including the entrapment releases, are listed in our CCSD code library.

Documentation requirements for CCSD A6400 claims

A complete operative note is the single most important document for an A6400 claim. Insufficient documentation is consistently cited by UK private insurers as a leading reason for peripheral nerve repair claim rejection.

Thorough documentation across every surgical episode protects against retrospective audit as well as prospective denial. To support an A6400 submission, the operative note should contain each of the following elements.

• Named nerve(s) repaired. State the specific nerve: “right median nerve at the level of the wrist” not “peripheral nerve”. Vague descriptors lead to insurer queries and delays.
• Mechanism and etiology. Document the cause of injury (laceration, tumor excision, traumatic transection) and the relevant ICD-10 diagnosis code. The diagnosis must align with the procedure. A compressive neuropathy diagnosis paired with A6400 creates a mismatch that prompts review.
• Repair technique used. State whether epineural or fascicular repair was performed, the suture material and gauge, and whether an operating microscope was used.
• Intraoperative findings. Describe nerve-end condition at the time of repair: fresh cut edges vs. neuroma formation, gap length before trimming, and whether tension-free apposition was achieved.
• Pre-authorization reference number. If the insurer required pre-authorization, the authorization reference must appear on the claim form. Absence of this number is an automatic query trigger for most major insurers.
• Consultant details. Record the operating surgeon’s name, GMC number and insurer recognition number. This confirms the payer recognizes the surgeon for this procedure category.

Clinical record software that timestamps operative entries and flags missing fields before a claim is generated helps here. Billing staff catch an unnamed nerve or a missing suture gauge at the point of care, not after submission.

Pre-authorization: What UK insurers require for nerve repair

Peripheral nerve repair is typically classed as elective or semi-elective surgery. Most major UK private medical insurers require pre-authorization before the procedure. Proceeding without it doesn’t necessarily void the claim, but it significantly raises the chance of delay, reduction or denial.

Requirements differ between insurers. Checking the Bupa procedure fee schedule and the equivalent schedules for other insurers before booking surgery tells admin staff whether authorization is mandatory. It also shows which clinical information the insurer needs to process the request.

Emergency peripheral nerve repairs, such as those required immediately following traumatic laceration, may be exempt from pre-authorization requirements. Confirm the emergency exemption terms with the specific insurer and document the clinical urgency in the notes to support retrospective approval. Always verify current insurer schedules, as pre-authorization policies are subject to change.

Common reasons peripheral nerve repair claims are denied

Understanding the pattern of A6400 denials helps billing staff address the most likely failure points before submission rather than in an appeal. Most denials for peripheral nerve repair fall into five categories.

1. Missing pre-authorization. The insurer’s pre-auth reference is not on the claim form, or authorization was never obtained. For elective cases, this is avoidable. Establish a pre-auth check as a hard gate in the booking workflow.
2. Wrong code submitted. A6810 submitted when A6400 was appropriate, or vice versa. Review the operative note before code selection: if no suture was placed on the nerve, A6400 is incorrect. If nerve continuity was restored by suture, A6810 is incorrect.
3. Insufficient operative note detail. The note does not name the specific nerve, does not describe the repair technique, or does not explain the time between injury and repair. Insurers increasingly review operative documentation before releasing payment for surgical codes.
4. Diagnosis-procedure mismatch. The ICD-10 diagnosis code submitted describes a compressive neuropathy or demyelinating condition rather than a structural nerve injury. Repair of peripheral nerve logically follows traumatic or iatrogenic nerve division. A mismatch flags the claim for clinical review.
5. Unbundled nerve graft. A graft was performed but only A6400 was submitted, or both A6400 and a graft code were submitted for the same nerve. Nerve grafting replaces direct repair, so the two codes don’t stack for a single nerve.

When a claim is denied, request the specific denial reason in writing. Most UK insurers provide a reason code with the rejection notice. Match the reason code to the operative note, correct the specific deficiency, and resubmit with a covering letter addressing the denial.

How to submit a CCSD A6400 claim: Step by step

A structured claim submission process for CCSD A6400 reduces the chance of avoidable denial. The steps below reflect best practice for nerve repair coding in UK private practice.

1. Confirm insurer recognition. Verify that the operating consultant is recognized by the patient’s insurer for the relevant surgical specialty. Unrecognized consultants cannot bill directly to most UK private medical insurers.
2. Obtain pre-authorization. Contact the insurer’s pre-auth team before the procedure date using the CCSD code A6400 and the applicable ICD-10 diagnosis code. Record the authorization reference number.
3. Dictate or complete the operative note immediately post-procedure. Include all elements listed in the documentation section: named nerve, mechanism, technique, suture specification, intraoperative findings, and any adjunctive procedures. Digital operative forms with mandatory fields stop incomplete records from reaching the billing team.
4. Select the correct CCSD code. Confirm from the operative note that suture repair was performed. If a graft was used, substitute the appropriate graft code. If the nerve was only released, use A6810.
5. Complete the claim form. Enter CCSD Code A6400, the ICD-10 diagnosis code, the pre-authorization reference and the procedure date. Add the consultant’s insurer recognition number and the hospital or facility details. Check that the patient’s insurer membership number is current.
6. Submit within the insurer’s time limit. Most UK private medical insurers impose a claim submission deadline of three to six months from the procedure date. Submissions outside this window are typically declined regardless of clinical validity.
7. Track the claim and chase unresolved submissions. A claim not acknowledged within 28 days should be followed up directly with the insurer. Pabau can track every open claim and automate the follow-up.

Billing peripheral nerve repair in private practice

Consultant surgeons billing A6400 in independent private practice face a set of administrative challenges distinct from NHS coding. Fee schedules, recognition requirements, and claim processes vary between the four major insurers and several smaller providers. A few practical habits reduce friction.

Maintain a procedure-specific coding reference. Keep a summary card or digital reference for the nerve repair code family: A6400 (direct repair), A6810 (neurolysis), and the current CCSD nerve graft code. Admin staff who check it before finalizing a claim are less likely to submit A6810 when A6400 is appropriate.

Coordinate anesthetic billing separately. The consultant surgeon and the anesthetist each submit their own claim. Including an anesthetic component in the A6400 submission leads to rejection or overpayment queries. Confirm with the anesthetist before submission that their billing is handled independently.

Understand insurer fee schedules for complex or outlier repairs. Some insurers allow enhanced fee submissions for unusually complex repairs, backed by clinical justification. Examples include multiple nerve repairs, prolonged operative time, or a secondary repair after a failed primary repair.

Consult the relevant insurer schedule, and send an outlier justification letter with the claim when the complexity is exceptional. The CCSD technical guide explains how complexity affects fee calculation.

Track your own coding patterns. A practice that reviews its A6400 acceptance and denial rates quarterly can spot systemic documentation or coding errors before they pile up. Automated workflows that trigger a documentation check before claim submission reduce preventable denials.

How Pabau cuts insurer queries on A6400 claims

In many surgical practices, the operative note is dictated days later, the code is picked from memory and claims are chased from a spreadsheet. Each hand-off is another chance for an A6400 claim to come back with a query.

Pabau keeps those steps in one patient record. Digital operative forms with mandatory fields prompt the surgeon to record the nerve, the technique and the suture gauge before the note is saved. The pre-authorization reference sits in the same file, and the claim is tracked until the insurer pays.

The result is fewer insurer queries and faster payment for peripheral nerve repair cases. Your billing team spends its week on new claims rather than appeals.

Reduce CCSD billing errors across your private practice

Pabau keeps CCSD coding, operative notes and insurer claims in one place for consultant surgeons and their admin teams. Fewer claims come back with queries.

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Conclusion

The operative note decides every A6400 claim. Read it before choosing between A6400, A6810 and a graft code. If it doesn’t name the nerve and the technique, send it back to the surgeon.

Pre-authorization is the other check worth making before the list is booked. Both checks cost a few minutes per case, while a denied claim can cost weeks of appeals.

Pabau’s claims management tools keep the note, the authorization and the claim in one record. Book a demo to see how that keeps peripheral nerve repair claims moving for your practice.

Continue your research

Coding a deeper entrapment release? CCSD code A6600 explains when release of a deeply placed peripheral nerve applies.

Submitting to Bupa? Bupa CCSD codes walks through how Bupa structures its schedule and submissions.

Checking what a procedure pays? Bupa procedure codes and fee schedule lists Bupa’s codes alongside their fee guidance.

Frequently asked questions