CPT code 26418 – Finger extensor tendon repair without graft

Key takeaways

CPT code 26418 reports a finger extensor tendon repair without a free graft. It covers primary and secondary repairs, per tendon.

Location picks the code, not timing. Repairs on the back of the hand go to 26410, and grafted finger repairs go to 26420.

Report one unit per tendon. Each digit also needs its F-series modifier, FA to F4 on the left and F5 to F9 on the right.

Pair a laceration or rupture diagnosis, such as S66.32- or M66.24-. Keep the 7th character A, since surgery is active treatment.

The 90-day global period bundles routine post-op visits. An unrelated visit needs modifier 24, and a return to the OR needs 78.

What CPT code 26418 covers, and what it doesn’t

CPT code 26418 reports one surgical repair of an extensor tendon on a finger, done without a free tendon graft.

The full descriptor reads “Repair, extensor tendon, finger, primary or secondary; without free graft, each tendon.” The American Medical Association maintains it in the hand and fingers repair range, 26340 to 26596.

Each part of the descriptor does a job on the claim. Here is how to read it:

• Extensor tendon: the tendons that straighten the finger, not the flexors on the palm side.
• Finger: the repair sits on the digit itself. A tendon cut over the back of the hand belongs to 26410 instead.
• Primary or secondary: a same-day repair and a delayed or revision repair share this one code.
• Without free graft: the surgeon sutures the tendon ends directly, with no graft harvested from elsewhere.
• Each tendon: you report one unit for every tendon repaired, not one per hand or per session.

So the code is driven by anatomy and technique. A delayed repair does not need a different code. That surprises coders who learned these codes as a primary and secondary pair.

Hand or finger? Where 26418 sits in its family

The extensor tendon codes split on three questions. Is the repair on the hand or the finger? Was a graft used? Does it involve the central slip or the distal insertion? Answer them in order, as the grid below does, and the right code falls out.

Two boundaries trip coders most. First, a repair at the fingertip insertion is a mallet code, 26433 or 26434, never 26418. Second, a central slip reconstruction has its own codes, 26426 and 26428, even though the tendon sits on the finger.

How a 26418 claim moves from op note to payment

A clean 26418 claim follows the same path every time. Each step depends on the one before it, so a weak op note weakens the whole claim.

1. The surgeon documents the finger, the tendon, the injury and the repair technique.
2. The coder confirms the site is the finger and that no free graft was used.
3. The coder counts the tendons repaired and sets one unit or line per tendon.
4. Each line gets its F-series digit modifier, plus 51 or 59 where the payer needs them.
5. A diagnosis from S66.- or M66.24- is linked to every line, with the right 7th character.
6. The claim goes to the payer on a CMS-1500 through your clearinghouse, and the 90-day global clock starts.

Most rework happens at step three or four. The payer sees units that the note does not support, or a digit that the modifier contradicts. Our CMS-1500 form guide maps the boxes where those units, modifiers and diagnosis pointers go.

Which modifiers does CPT 26418 need?

Every 26418 line needs a digit modifier, and some need a second one. Start with the F-series, then decide on 51 or 59.

F-series digit modifiers

These HCPCS Level II modifiers tell the payer exactly which finger you repaired. The left hand runs FA to F4, and the right hand runs F5 to F9.

Watch out for TA. It identifies the left great toe, so it never belongs on a hand claim.

Modifiers 51 and 59

Modifier 51 flags multiple procedures in one session. Medicare applies its multiple procedure rules on its own, while many commercial payers want 51 on the additional lines. Check each payer’s manual before you append it.

Modifier 59, or the more specific XS, is different. Use it only when an NCCI edit bundles another procedure with 26418. That procedure must also have been done at a separate site. Never add 59 just to get a line paid.

ICD-10 codes that support a 26418 claim

The diagnosis has to match the finger and the cause. Traumatic cuts use the S66.32- laceration codes, while non-traumatic ruptures use M66.24-.

Keep the 7th character at A while the patient is in active treatment, and surgery counts as active treatment. That holds even when the repair is delayed. Character D is for routine healing visits afterward, such as splint checks.

Also avoid the S66.39- codes for a cut tendon. They describe other injuries of the extensor tendon, not lacerations. S66.391A, for example, covers another injury to the left index finger extensor.

The 90-day global period after a 26418 repair

CPT 26418 carries a 90-day global period under the CMS fee schedule. Routine care tied to the repair is paid inside the surgical fee. It never goes out as a separate charge.

• Bundled: the initial splint, wound checks, suture removal and routine follow-up visits for this repair.
• Billable with modifier 24: an office visit for an unrelated problem during the global period.
• Billable with modifier 78: an unplanned return to the operating room for a related complication.
• Billable with modifier 79: an unrelated procedure during the global period.
• Outside the surgeon’s global: hand therapy billed by a separate therapist under its own codes.

Confirm the current global indicator on the CMS Physician Fee Schedule lookup for your payment year. Pull RVUs and rates from there too, rather than from an old cheat sheet.

Billing 26418 when more than one tendon is repaired

Because the descriptor says “each tendon,” two finger tendons repaired without graft means two units of 26418. Two fingers means at least two lines, each with its own F modifier.

Payers then check the units against a medically unlikely edit, or MUE. Look up the current MUE for 26418 before you submit a multi-tendon claim. Units above it are usually denied, so check how the payer handles appeals with records.

The op note carries all the weight here. It should name each tendon, its finger and the repair done. A line like “multiple extensor tendons repaired” will usually be cut back to one unit.

Common mistakes that get 26418 denied

Most 26418 denials come from a handful of repeat errors. Fix them at the source and the appeals mostly disappear. When one slips through, the remittance’s denial codes tell you which error the payer found.

Before you submit: A 26418 checklist

Run through these checks on every 26418 claim. They take a couple of minutes and catch most avoidable denials.

• The op note names the finger, the tendon and the side.
• The repair sits on the finger, not the hand or the fingertip insertion.
• The note states that no free graft was used.
• Units match the number of tendons repaired.
• Every line carries the right F modifier, with 51 or 59 only where the payer needs it.
• The diagnosis matches the finger, side and cause, with 7th character A.
• Prior authorization is on file if the patient’s plan requires it.
• Any visit in the next 90 days is checked against the global rules.

A clean claim starts with the op note. When the note answers each item above, coding the claim takes minutes rather than a back-and-forth with the surgeon.

How Pabau keeps 26418 claims moving

Hand surgery billing often means retyping details from the chart into a separate claims tool. Each retyped field is another chance for a wrong digit or a missing authorization number.

In Pabau, the practice management platform we build, the claims management feature fills the CMS-1500 from the patient record. The CPT code on the service lands on the charge line. The ICD-10 slots start from the recorded problem list.

Before the claim can be sent, Pabau checks that required fields like member IDs and authorization numbers are complete. US claims then go out through the Claim.MD clearinghouse, with eligibility checks and claim tracking.

Remittances post back to the same place. Your coder still owns the modifier and unit decisions, but spends less time on data entry.

Spend less time keying hand surgery claims

Pabau fills claims from the patient record and checks required fields before sending. US claims go out through Claim.MD with status tracking.

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Conclusion

Code 26418 rewards precise op notes. When the note shows a finger-level repair, no graft and a clear tendon count, the code, units and modifiers follow without guesswork.

Most denials come from the edges of the code family. Think hand versus finger, mallet versus shaft, or toe modifiers on a hand. Build those checks into your workflow, and keep reading the payer manual for 51 and MUE rules.

If your team still retypes surgical charges into a separate claims tool, that is the easiest time to win back. Book a demo to see how Pabau turns the chart into a ready-to-send claim.

Continue your research

Want to understand how claim edits work across your codes? Medical billing compliance covers NCCI edit logic, audit triggers and how to build compliant billing workflows.

Need a structured approach to payment posting? Revenue cycle management explains the process from claim creation through payment reconciliation.

Choosing a clearinghouse for surgical billing? Claim.MD clearinghouse overview explains how the integration handles electronic claims and real-time eligibility checks.

Seeing the same denials month after month? Denial management in healthcare shows how to track root causes and stop repeat rejections.

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