ICD code S75.901D – Unspecified right femoral blood vessel injury, subsequent encounter

Key takeaways

S75.901D codes an unspecified injury to an unspecified blood vessel of the right leg, at hip and thigh level.

The sixth digit 1 already fixes the laterality as the right leg, so only the vessel type is unspecified.

The seventh character D applies while active treatment continues after the initial encounter, and using A instead triggers most denials.

Query the record for the injured vessel before billing this code, because S75.001D and S75.801D name the vessel and survive specificity edits.

Practice management software like Pabau flags seventh-character mismatches and vessel-specificity conflicts before the claim is submitted.

ICD-10 Code S75.901D: Definition and clinical description

ICD-10 Code S75.901D is a seventh-character extension of the parent subcategory S75.901.

That subcategory covers an unspecified injury of an unspecified blood vessel at hip and thigh level, right leg. The “D” extension designates a subsequent encounter. The patient is still in the active treatment and healing phase, but has already been seen at least once for the acute injury.

Per the CMS ICD-10-CM coding guidelines, a code from category S75 applies to traumatic vascular injuries at the hip and thigh. It does not apply to nontraumatic vascular conditions such as atherosclerosis or chronic venous insufficiency.

The code sits within Chapter 19 of ICD-10-CM (Injury, Poisoning and Certain Other Consequences of External Causes, S00-T88). It is fully billable as a standalone diagnosis code and needs no additional code from another chapter to be valid. External cause codes (W, V, X, Y) should still accompany it when the mechanism of injury is known.

Anatomical scope: What “femoral blood vessel” covers here

The S75 category covers traumatic injuries to blood vessels at the hip and thigh level. That includes the femoral artery, the femoral vein, and the great saphenous vein at the thigh. When the subcategory is “.9”, the documentation has not identified which vessel was injured. That position is legitimate when the operative report or trauma note cannot confirm whether the damaged structure was artery or vein.

Two boundary notes apply. Injury of the popliteal artery is excluded from S75 and is captured under S85, which covers blood vessels at lower leg level. Nontraumatic femoral artery conditions, such as femoral artery aneurysm or peripheral artery disease, are coded outside Chapter 19 entirely.

• Included: Traumatic laceration, contusion, or puncture of a right-leg vessel at hip or thigh level during the active healing phase
• Included: Post-surgical vascular follow-up when the initial trauma involved an unspecified vessel of the right leg
• Excluded (use S85): Injury of popliteal artery or vein
• Excluded: Nontraumatic femoral vascular conditions (peripheral artery disease, chronic venous insufficiency)
• Excluded (use “S” suffix): Late effects or sequela of femoral vessel injury once healing is complete

Seventh character D: When subsequent encounter applies

The seventh character “D” signals a subsequent encounter. The CDC/NCHS ICD-10-CM guidelines define that as any encounter where the patient receives active treatment for the injury after the initial encounter phase has ended. Wound checks, vascular repair follow-ups, physical therapy visits and post-operative monitoring all qualify, provided the injury is still healing.

One documentation trap recurs. The provider writes “follow-up for femoral artery repair” without stating the healing status, which leaves the seventh character undecided. Coders should query whether the wound is still healing or whether the patient is now being treated for a sequela. Per ICD-10-CM Official Guidelines Section I.C.19.a, the seventh character reflects the nature of the current encounter, not the provider’s specialty or the visit number.

Adjacent and easily confused codes

S75.901D already carries the laterality, so the codes worth checking against it are the ones that name the vessel. The AAPC ICD-10-CM code reference notes that unspecified codes belong only in records that genuinely lack the information. Where a provider query would resolve which vessel was injured, the query comes first.

Two digits carry the specificity in this family, and reading them in order settles most code selections. The fifth character names the vessel, and the sixth names the side. A sixth digit of 1 means the right leg, 2 means the left, and 9 means the record does not say. The grid below maps both axes onto the base code before the seventh character is added.

Documentation requirements to support the claim

A claim carrying ICD-10 Code S75.901D must be backed by a medical record that establishes five facts. Each one lives in a different part of the chart. A coder who reads only the current visit note will usually miss at least one.

• Prior traumatic vascular injury confirmed: The record must reference a previous injury to a blood vessel at the hip or thigh level. An operative report, ED note, or discharge summary from the initial encounter usually carries it.
• Active healing still in progress: The current note must indicate ongoing wound healing, vascular monitoring, or rehabilitation. A note that simply states “resolved” without specifying sequela shifts the correct seventh character to “S”.
• Right leg confirmed: S75.901 is the right-leg code, so the record must support that side. A note documenting the left leg sends the claim to S75.902D, and a record silent on the side sends it to S75.909D.
• Vessel type addressed: The record must either name the injured vessel or show that it was never identified. Do not settle on the unspecified-vessel code when the operative report names the femoral artery or vein.
• Cause of injury documented: An external cause code (W, V, X, or Y category) should accompany S75.901D. CMS expects mechanism-of-injury coding on trauma claims, particularly for inpatient and facility encounters.

Payer requirements for S75.901D claims

Medicare and most commercial payers accept S75.901D on outpatient and inpatient claims when the documentation supports the subsequent encounter designation. The payer-facing requirements are consistent across major carriers, though state Medicaid programs may add LCD-level restrictions.

• Prior authorization: Not typically required for the diagnosis code itself. The associated CPT procedure, such as vascular repair follow-up or wound management, may require it depending on the payer and setting.
• LCD/NCD policies: No national coverage determination specifically targets S75.901D. Local Coverage Determinations for related procedures, such as physical therapy and wound care, may require the diagnosis to appear on a covered-condition list. Confirm with the Medicare Administrative Contractor for your jurisdiction.
• Vessel-specificity scrutiny: Several commercial payers, including some Blue Cross Blue Shield plans, run specificity edits here. They flag an unspecified-vessel code when an earlier claim on the same patient named the vessel. A pre-submission check catches that conflict while the claim can still be corrected.
• Inpatient vs. outpatient: On inpatient claims, S75.901D may appear as a secondary diagnosis, either a complication or a comorbidity. It is unusual as a principal diagnosis there, since the acute traumatic injury would have been addressed at the initial encounter.

Common claim denials and how to avoid them

Denial patterns on this code cluster around three coding errors, and each one has a different fix. Our reference on medical billing denial codes shows which CARC codes map to which error. The correction then comes from the remittance rather than from a guess.

The electronic remittance advice on a denied claim names the CARC reason. That reason tells you whether the fix is a seventh-character change, a vessel query, or an external cause code. Rolling those reasons up by code, rather than reading one remit at a time, is what denial management in healthcare turns into a repeatable routine. The pattern shows up long before the write-offs do.

CPT codes commonly billed alongside this diagnosis

The CPT codes billed alongside S75.901D reflect the aftercare the patient is receiving during the subsequent encounter phase. Pairing the wrong CPT code with the diagnosis is a second denial vector, independent of the seventh-character issue. So is failing to document medical necessity for the procedure itself.

The five pairings below cover most subsequent encounter claims carrying this code, from active repair through to wound care and rehabilitation.

ICD-11 and the future of femoral vascular injury coding

ICD-11 has been adopted by WHO and is in limited implementation internationally. The United States has not set a mandatory transition timeline as of the 2026 fiscal year. CMS continues to mandate ICD-10-CM for all HIPAA-covered transactions. Nothing about femoral vascular injury coding moves away from the S75 category in the meantime. The WHO ICD-10 browser remains the reference for international coding contexts.

ICD-11 does capture traumatic vascular injuries at the thigh level, with greater anatomical specificity than the S75 category offers. Practices that tighten their vessel-type and laterality documentation now will face a shorter transition curve whenever US adoption is mandated.

How Pabau keeps seventh characters and vessel specificity off your denial list

In most practices, the seventh character is decided at the end of the day. A coder reads a visit note written hours earlier and infers the healing status from it. The initial encounter note that names the vessel sits in a different record, often under a different provider. Nothing connects the two until a payer does it for you, on a remittance.

Practice management software like Pabau closes that distance by building the claim from the encounter itself. The patient’s earlier encounters, the operative report, and the diagnosis history sit on the same record the coder is working in. The side and the vessel documented in January are still visible in March. Pabau’s claims management software then validates the seventh character and the CPT-to-ICD pairing before the claim leaves the practice.

The outcome for a vascular or trauma billing team is fewer claims coming back for a correction they could have made in seconds. Every subscription includes the full feature set, so claim validation is not something you add on later.

Fewer denials on trauma codes start with cleaner claims

Pabau validates ICD-10 seventh characters, laterality and CPT pairings before your claims reach the payer. See how the workflow fits your vascular and trauma billing team.

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Conclusion

S75.901D is more specific than it looks. The laterality is already decided, so the only open question the code leaves is which vessel was injured. Treat it as a placeholder for laterality and you will keep billing it on left-leg injuries that belong to S75.902D.

The two errors worth engineering out are the seventh character and the unnamed vessel. Both are decided by what somebody wrote in an earlier note, which means the fix is a pre-submission check rather than a coder working harder. Practices that add that check stop re-coding the same claim twice.

To see how claim validation fits your vascular and trauma billing workflow, book a demo.

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