ICD-10 Code S85.312A: Laceration of saphenous vein, left leg

Key Takeaways

S85.312A is a billable ICD-10-CM code describing laceration of the greater saphenous vein at lower leg level, left leg, initial encounter.

The parent code S85.312 is non-billable. Coders must use a child code: S85.312A (initial), S85.312D (subsequent), or S85.312S (sequela).

Laterality is mandatory. S85.311A covers the right leg; S85.319A covers unspecified side. Using the wrong code risks claim denial.

Pabau’s claims management software supports clean claim submission for vascular injury codes, with Claim.MD clearinghouse integration for US payers.

Missed laterality is the fastest route to a denied claim on vascular injury codes. S85.312A locks in all three critical specifics: the injured vessel (greater saphenous vein), the anatomical level (lower leg), and the affected side (left). Get any one of these wrong and the claim comes back. This reference covers every coding dimension of ICD-10 Code S85.312A, from billable status and 7th character selection to MS-DRG grouping, POA requirements, and the ICD-9 crosswalk.

The 2026 edition of ICD-10 Code S85.312A became effective October 1, 2025. According to the CDC/NCHS ICD-10-CM tool, this code is valid for submission across all applicable claim types. This page covers the full code profile, including encounter type guidance, sibling codes, and clean-claim documentation tips.

ICD-10 Code S85.312A: Quick reference

ICD-10 Code S85.312A describes a specific traumatic vascular injury with full laterality and encounter-type specificity. The table below summarises the core code profile.

What S85.312A means: code description and clinical context

Every character in S85.312A carries diagnostic weight. Breaking down the code string reveals the full clinical picture.

The greater saphenous vein (GSV) is the longest vein in the body, running from the dorsum of the foot along the medial aspect of the leg to the femoral vein in the groin. At lower leg level, it lies superficially along the medial tibia, making it vulnerable to lacerations from trauma, falls, or sharp-object injuries.

Clinical scenarios requiring ICD-10 Code S85.312A include traumatic lacerations from broken glass or metal, sports injuries with skin and venous penetration, and intraoperative inadvertent GSV laceration at the lower leg. Documentation should specify the left leg explicitly, the nature of the wound (laceration vs. other injury), and the anatomical level (lower leg, not thigh or ankle).

Is S85.312A a billable code? Validity and submission status

S85.312A is a billable/specific ICD-10-CM code, valid for claim submission across Medicare, Medicaid, and most commercial payers. The CMS ICD-10 codes page confirms its inclusion in the 2026 ICD-10-CM tabular list, with an effective date of October 1, 2025.

“Valid for submission” means the code is specific enough for payers to process without requiring a more detailed child code. In this instance, S85.312A is already the most specific code in its subcategory chain. Practices using Pabau can route these diagnoses through Claim.MD clearinghouse integration, which supports CMS-1500 and 837P claims for over 4,000 US payers, including real-time eligibility checks before submission.

Understanding medical billing workflows for vascular injury codes is essential for avoiding preventable denials. The most common submission error is using the parent code S85.312 directly; this lacks the 7th character and will reject at the clearinghouse level.

7th character subclassification for S85.312

S85.312 requires a 7th character to be billable. Three valid child codes exist under this parent.

The “A” encounter applies every time active treatment is being provided for the injury itself. Once active treatment ends and the patient returns for routine monitoring or management of residual effects, switch to “D.” When the visit is specifically treating a late complication caused by the original laceration, “S” applies.

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S85.312A vs S85.311A vs S85.319A: laterality and sibling codes

Correct laterality documentation prevents one of the most avoidable coding errors in the S85.31x subcategory. The three sibling codes for laceration of the greater saphenous vein at lower leg level are:

S85.319A (unspecified side) should be a last resort. Most payers prefer or require laterality-specific codes. If the clinical note clearly documents left leg, S85.312A is the correct choice. For parallel reference on how laterality coding works across traumatic vascular injuries, the ICD-10 coding approach to vascular injuries follows similar laterality-first principles.

Parent code S85.312 and the S85 category

S85.312 is a non-billable header code. It serves as the parent in the ICD-10-CM hierarchy but cannot be submitted on a claim without a 7th character suffix.

The full code path for S85.312A is:

• S00-T88 – Injury, poisoning and certain other consequences of external causes
• S80-S89 – Injuries to the knee and lower leg
• S85 – Injury of blood vessels at lower leg level
• S85.3 – Laceration of greater saphenous vein at lower leg level
• S85.31 – Laceration of greater saphenous vein at lower leg level (laterality series)
• S85.312 – Laceration of greater saphenous vein at lower leg level, left leg (non-billable)
• S85.312A – Initial encounter (billable)

Within the S85 category, coders working on vascular surgery or trauma cases will encounter a range of related subcategories. For broader context on revenue cycle management for vascular specialties, accurate S85 coding directly influences MS-DRG assignment and inpatient reimbursement.

Excludes notes and coding guidelines for S85.312A

The S85 category carries excludes notes that define its boundaries. These are important for dual-coding scenarios and avoiding claim edits.

Excludes2 notes for S85: The S85 category excludes2 injury of blood vessels at ankle and foot level (coded to S95.-). This means an injury to the saphenous vein at ankle level, rather than lower leg level, maps to a different code range. The two code blocks may be reported together when clinically appropriate (excludes2 vs. excludes1 distinction).

Additionally, popliteal artery and vein injuries (S85.0-, S85.5-) are in the same S85 category but represent different vessels and require their own codes. Do not use S85.312A when the injury involves the popliteal vessels or when the injury level is at the thigh rather than the lower leg.

For guidance on navigating claim edits caused by incorrect excludes note interpretation, denial management in healthcare covers the most common payer-level edit patterns. Applying medical billing compliance principles to ICD-10 documentation helps reduce preventable rejections. Per AAPC’s ICD-10-CM lookup resources, excludes notes should be reviewed at both the code and category level.

Approximate synonyms and clinical documentation terms

The ICD-10-CM index includes several clinical synonyms that map to S85.312A. Recognition of these terms helps documentation staff and coders align clinical language with the correct code.

• Laceration of greater saphenous vein, left lower leg
• Wound of left greater saphenous vein at lower leg level
• Open wound, left greater saphenous vein, lower leg
• Left saphenous vein laceration, lower extremity
• GSV laceration, left leg
• Traumatic laceration of left saphenous vein
• Cut of greater saphenous vein, left leg, lower leg level

Coders should watch for operative reports or ED notes using shorthand such as “GSV cut” or “saphenous laceration left LE.” These map directly to S85.312A when documented at lower leg level for an initial encounter. For ICD-10-CM documentation best practices that support ICD-10-CM coding accuracy, specificity in clinical notes at the point of care reduces downstream querying time.

MS-DRG grouping and POA indicator for S85.312A

For inpatient facility billing, two additional coding dimensions apply: MS-DRG assignment and the Present on Admission (POA) indicator.

MS-DRG grouping

According to Unbound Medicine, S85.312A groups within MS-DRG v41.0. The specific DRG assignment depends on the presence of a major complication or comorbidity (MCC) or complication or comorbidity (CC). Vascular injury codes in the S85 range typically fall within DRG groups covering lower extremity injuries, with the grouping varying based on the full claim’s secondary diagnoses. Coders should reference the ResDAC guidance on ICD codes in Medicare files for DRG validation within claims data workflows.

POA indicator

S85.312A is not POA-exempt. For inpatient admissions, the POA indicator must be reported. The options are:

• Y (Yes) – The laceration was present at the time of inpatient admission
• N (No) – The laceration developed after admission (e.g. intraoperative vascular complication)
• U (Unknown) – Documentation is insufficient to determine POA status
• W (Clinically undetermined) – The clinician is unable to determine POA status

POA reporting matters for Hospital-Acquired Condition (HAC) review. An intraoperative saphenous vein laceration coded as “N” may trigger HAC scrutiny and affect reimbursement. Ensure the operative report clearly documents when the injury occurred relative to admission. Proper POA documentation also feeds into superbill accuracy for facilities that generate superbills from EHR data. Claims management software with built-in ICD-10 catalogues can flag incomplete POA fields before submission.

ICD-9-CM to ICD-10-CM crosswalk for S85.312A

For historical record comparison and payer crosswalk documentation, S85.312A maps back to ICD-9-CM via the CMS General Equivalence Mapping (GEM) files. The approximate ICD-9-CM equivalent is:

ICD-9-CM code 904.3 did not distinguish between greater and lesser saphenous veins, nor between laterality, encounter type, or anatomical level. The GEM crosswalk is approximate. Payers may not accept GEM mappings for all claim types, particularly when prior-period billing comparisons are reviewed. Always verify with the specific payer before relying on a crosswalk for historical claims. The ICD List crosswalk tool provides an accessible interface for ICD-9-to-ICD-10 lookups with GEM flag notation. Understanding ICD-10-CM coding context for each code helps coders interpret GEM crosswalk results correctly rather than accepting them at face value.

When to use S85.312A vs S85.312D vs S85.312S

Selecting the right 7th character is the most actionable coding decision for this code. The clinical scenario, not the calendar date, determines encounter type.

1. Use S85.312A (initial encounter) when the provider is actively treating the vascular laceration for the first time. This includes the ED visit for repair, the operating room for primary vascular closure, and any inpatient stay where active treatment of the laceration is the primary reason for care. A patient who sees multiple surgeons for the same injury during active treatment continues to use “A” at each visit as long as treatment is ongoing.
2. Use S85.312D (subsequent encounter) when the injury is healing and the patient is receiving routine wound care, suture removal, or monitoring. The injury itself is no longer receiving active treatment; the visit manages the healing process. This is the most commonly misapplied 7th character: coders who continue to use “A” through multiple post-operative wound checks are miscoding.
3. Use S85.312S (sequela) when the current condition is a late effect directly caused by the original saphenous vein laceration. Examples include chronic venous insufficiency, post-phlebitic syndrome, or persistent scarring. The sequela code is reported as an additional code describing the nature of the sequela; the original injury code S85.312S is listed as secondary.

For documentation that supports clean claim submission, the clinical note should state whether the current encounter represents initial treatment, follow-up care, or management of a late effect. This language maps directly to the ICD-10-CM 7th character guidance and removes ambiguity during coding review.

How to document S85.312A for clean claims

No competitor page for this code provides specific EHR documentation guidance. This section fills that gap.

A clean claim for S85.312A requires the clinical note to support four specifics: the injured vessel, the anatomical level, laterality, and the encounter type. Missing any one of these invites a documentation query or a denial.

• Named vessel: Document “greater saphenous vein” explicitly, not just “vein” or “saphenous vein.” The GSV distinction separates this from lesser saphenous vein injuries.
• Anatomical level: State “lower leg” or “below the knee.” Avoid “leg” without qualification; the popliteal zone and the ankle each map to different code ranges.
• Laterality: State “left leg” explicitly. For bilateral injuries, two codes apply: S85.311A (right) and S85.312A (left).
• Encounter type: Use clinical language that maps cleanly: “initial surgical repair” (A), “routine wound follow-up” (D), or “treatment of chronic venous insufficiency following prior laceration” (S).
• Injury mechanism: Document how the laceration occurred. Trauma documentation supporting medical necessity reduces the risk of clinical validation requests.

Practices on Pabau can submit S85.312A claims through the Claim.MD clearinghouse integration, which validates ICD-10 codes against the built-in catalogue, runs eligibility checks before submission, and returns Electronic Remittance Advices (ERAs) for reconciliation. For practices managing surgical or vascular cases, plastic surgery EMR functionality within Pabau supports the documentation workflow from consultation through billing.

Conclusion

ICD-10 Code S85.312A is a billable, submission-ready code when documentation covers all four specifics: the greater saphenous vein, lower leg level, left leg laterality, and the initial encounter. The most common errors are using the non-billable parent S85.312, applying the wrong 7th character after active treatment ends, and leaving laterality unspecified.

Pabau’s claims management software with Claim.MD integration handles ICD-10-validated claims submission for vascular injury codes across 4,000+ US payers. To see how it fits your billing workflow, book a demo.

Continue your research

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