ICD code S61.311A – Laceration without foreign body of left index finger with damage

Key takeaways

ICD-10 Code S61.311A describes a laceration without foreign body of the left index finger with damage to the nail. Specifically, the 7th character A marks the initial encounter.

S61.311A is a billable, specific ICD-10-CM code valid for FY2026 submission (effective October 1, 2025). As a result, it cannot be submitted without the full 7-character code.

Documentation must confirm five elements: left laterality, index finger, nail damage, absence of foreign body, and initial encounter type. In short, missing any one risks denial.

In addition, practice management software like Pabau integrates with Claim.MD to submit ICD-10 claims electronically and track denials for wound care encounters.

ICD-10 Code S61.311A: code details at a glance

The table below captures the attributes coders verify before billing. Indeed, confirming billable status first prevents rejected submissions before they reach the payer.

What the S61.311A descriptor means, word by word

Each word in the official description carries a coding function. In fact, removing any element changes which code applies.

• Laceration – a torn or ragged wound, as distinct from a puncture, bite, or crush injury. Therefore, if the wound type differs, a different code in S61 applies.
• Without foreign body – no retained foreign material documented in the wound. Instead, if glass, metal, or debris is present and documented, S61.321A (with foreign body) replaces this code.
• Left index finger – laterality (left) and digit specificity (index, also called the second digit) are both required. In contrast, right index finger lacerations use S61.310A.
• With damage to nail – the nail plate, nail bed, or surrounding nail structure is involved. Left index finger lacerations without nail involvement use S61.211A instead.
• Initial encounter – the 7th character A confirms this is the first visit for active treatment of this wound. Instead, a follow-up or late-effect encounter takes a different character.

Read the code from left to right and each character adds one documentation requirement to the note.

The CDC/NCHS ICD-10-CM web tool confirms the full description and code hierarchy for S61.311A in the current tabular list.

Code hierarchy and parent codes

Reading the hierarchy from the chapter down to the billable code shows where each layer of specificity is added. Specifically, the parent hierarchy for S61.311A runs as follows:

7th character: choosing between A, D and S

The 7th character is the most frequently omitted element in finger laceration coding. As a result, submitting S61.311 without the encounter suffix makes the code invalid for claim submission. In addition, using the wrong character codes the wrong clinical situation.

Key rule: a patient can have multiple initial encounter visits (A) while they are still receiving active treatment for the same wound. The encounter type shifts to D only when the provider is managing the healing process rather than delivering active wound care. In fact, coding A for a suture removal visit when the wound is healing normally is a common audit finding.

Related codes in the S61.3 subcategory

Selecting the wrong sibling code is the second most common error in this subcategory. Specifically, the table below maps the distinctions across laterality, nail involvement, and foreign body status. For codes outside this subcategory, start from the ICD-10-CM code index.

The AAPC ICD-10-CM code lookup provides the full S61.3 subcategory listing for cross-referencing all sibling codes by laterality and digit.

S61.311A vs S61.321A: without vs with foreign body

This is the distinction most likely to trigger a payer audit. Indeed, both codes cover a left index finger laceration with nail damage. The only difference is whether foreign material is documented in the wound.

When wound exploration is performed but no foreign material is found, document the negative finding explicitly. Therefore, “Wound explored, no foreign body identified” supports S61.311A and protects the claim in audit review.

Documentation requirements for ICD-10 Code S61.311A

The clinical record must support each specificity element the code describes. As a result, a note that carries less detail than the code claims exposes the encounter to downcoding or rejection during audit review.

Required documentation elements for a valid S61.311A assignment:

• Left laterality confirmed – the note must state “left” finger, not just “index finger.” As a result, unspecified laterality defaults to an unspecified code and may not pass payer edits.
• Digit specified as index finger – document “index finger” or “second digit.” In contrast, a bare “finger laceration” does not support S61.311A.
• Nail involvement documented – describe the structure involved, such as “nail bed laceration,” “nail plate avulsion,” or “injury to nail matrix.” However, “Fingertip laceration” alone may be insufficient.
• Foreign body status documented – state that no foreign body is present, or document wound exploration with negative findings. In other words, silence on this element is not equivalent to “without foreign body.”
• Encounter type clinically justified – the note must reflect active treatment appropriate to an initial encounter. Instead, a follow-up wound check or suture removal shifts the encounter type to D.

A clean claim for S61.311A depends on all five elements appearing in the source documentation before coding begins. Otherwise, correcting documentation after the claim goes out carries compliance risk.

Common coding errors and how to avoid them

Finger laceration codes in the S61.3 subcategory generate avoidable denials. Therefore, catching the four errors below at the coding step is cheaper than appealing them after the payer responds.

• Submitting S61.311 without the 7th character. S61.311 is not a valid billable code, and every submission requires the full seven characters. In fact, many clearinghouses reject 6-character injury codes automatically, though some pass them through to the payer. Therefore, verify the complete code string before submission.
• Using the right index finger code for a left finger injury. S61.310A (right) and S61.311A (left) are identical except for laterality. As a result, coders working from templates that default to right-side codes create a laterality mismatch with the operative report or ED note.
• Omitting nail damage when the note documents it. A coder who reads “laceration of left index finger” and jumps to S61.211A has undercoded the encounter if the note also describes nail bed involvement. Therefore, read the full wound description before selecting the nail-involvement axis.
• Using the initial encounter code for follow-up visits. If the patient returns for suture removal or a wound check two weeks after the repair, the correct code is S61.311D. In fact, coding A at every visit is a pattern auditors flag as improper encounter-type assignment.

A single queue for coding, submission, and remittance review keeps these four errors from repeating. In short, that is the practical case for cleaner claims submission.

Billing S61.311A: submission and reimbursement context

S61.311A is the diagnosis code supporting a laceration repair CPT claim, not a standalone billable procedure. In other words, the ICD-10 code justifies medical necessity for the repair service. Practices submit these claims electronically in the standard 837P format, usually through a US claims clearinghouse.

Key billing considerations for S61.311A claims:

• Place of service matters – initial encounter laceration repairs frequently occur in the ED (POS 23) or urgent care (POS 20). The ICD-10 code travels with the claim regardless of setting, but facility versus non-facility RVU values affect physician reimbursement.
• Medical necessity pairing – link S61.311A to the laceration repair CPT code that matches the wound. Simple repair of a finger uses 12001-12007, and intermediate repair of a hand or finger uses 12041-12047. The ICD-10 code does not determine payment. Instead, the CPT code drives the RVU calculation.
• Payer-specific coverage policies apply – CMS covers laceration repair under Part B when medical necessity criteria are met. Individual payers may add requirements beyond ICD-10-CM code assignment, so verify coverage and prior authorization before the encounter where possible.

Verifying eligibility before the patient is seen surfaces coverage limits early. As a result, catching them before treatment reduces post-service billing disputes.

ICD-9-CM crosswalk for S61.311A

The ICD-9-CM system was retired in the US on October 1, 2015. Nevertheless, crosswalk lookups still matter for legacy data analysis and for audits of historical claims that reference pre-2015 encounters.

ICD-9-CM did not capture laterality, digit specificity, or nail involvement at the granularity ICD-10-CM now requires. Therefore, any crosswalk between S61.311A and an ICD-9 code is an approximation. The ICD List crosswalk tool provides bidirectional lookups for historical claim analysis.

Approximate synonyms and clinical terminology

Clinical staff and the coders abstracting from their notes often use different words for the same injury. Specifically, the list below maps common chart expressions to S61.311A.

• Nail bed laceration, left index finger
• Open wound of left index finger with nail involvement
• Left index finger laceration with nail plate damage
• Cut left second digit with nail matrix injury
• Left index finger wound with nail bed involvement, no foreign body
• Left index finger laceration with subungual injury, initial visit
• Traumatic nail bed injury, left index finger (without retained foreign body)

No synonym is interchangeable with another until the documentation confirms all five specificity elements. Ultimately, synonym recognition flags candidate codes, and the chart note settles which one applies.

How Pabau supports injury coding and claim submission

A wound care encounter usually crosses three systems. The note sits in the chart, the code goes into a billing tool, and the payer response lands in a separate inbox. Reconciling an S61.311A denial then means opening all three.

Practice management software like Pabau keeps the encounter in one record instead. The clinical note, the charge, and the claim status stay attached to the same visit. A coder can read the documentation behind the code without leaving the chart.

Submission runs through our Claim.MD integration, which sends the 837P and returns remittance advice against the same encounter. Denials arrive with their CARC codes tied to the visit they came from. An S61.311A rejection is then traceable to the note that supported it.

Keep wound care claims tied to the note

Pabau submits ICD-10-coded claims electronically through Claim.MD and returns remittance advice against the same encounter. Wound care visits, charges, and claim status stay in one record.

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Conclusion

S61.311A rewards a documentation habit more than a coding one. In fact, a provider who writes “left index finger, nail bed laceration, no foreign body identified” hands the coder a finished decision.

So the cheapest fix sits upstream of the billing queue. Build the four documentation anchors into the wound care note template, and the 7th character rule into the pre-submission check. As a result, the denials this code generates mostly stop there.

Pabau keeps the note, the charge, and the claim response on the same encounter. An S61.311A denial then points back at the documentation that produced it. Book a demo to see how injury and wound care billing runs end to end.

Continue your research

Managing claim denials for injury codes? Denial management in healthcare covers the workflows practices use to track, appeal, and reduce CARC-coded rejections.

Need a reference on clean claim submission standards? Submitting a clean claim explains what payers require before processing, including ICD-10 code completeness checks.

Exploring US clearinghouse options for ICD-10 claim routing? Claim.MD clearinghouse overview explains how Pabau’s clearinghouse partner handles 837P submissions and ERA returns.

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