ICD-10 code S72.302C: Unspecified fracture of shaft of left femur

Key takeaways

ICD-10 code S72.302C describes an unspecified fracture of the shaft of the left femur, initial encounter for open fracture type IIIA, IIIB, or IIIC.

S72.302C became billable on October 1, 2025, and its parent code S72.302 is not billable without a 7th character.

The 7th character C requires a documented Gustilo-Anderson type III grade, and coders cannot infer the type without the attending physician’s note.

Practice management software like Pabau links each ICD-10 code to the encounter record it came from.

ICD-10 code S72.302C is a billable diagnosis code for an unspecified fracture of the shaft of the left femur. It applies to the initial encounter, when the fracture is open and graded Gustilo-Anderson type IIIA, IIIB, or IIIC. The parent code, S72.302, cannot be submitted for reimbursement without a 7th character appended.

This guide covers the clinical meaning of S72.302C, how the Gustilo-Anderson classification maps to the 7th character, and the full sibling code family. It also covers the documentation the record needs and the coding errors that trigger denials.

ICD-10 code S72.302C: Definition and billable status

ICD-10 code S72.302C is a valid, billable ICD-10-CM diagnosis code. It is effective for dates of service on or after October 1, 2025, under the FY2026 code set. It is maintained jointly by the Centers for Medicare and Medicaid Services (CMS) and the National Center for Health Statistics (NCHS).

Orthopedic trauma teams and physical therapy EMR workflows both depend on accurate code assignment at the encounter level. Submitting the parent code S72.302 alone is a claim error, and payers reject it for lacking specificity.

Clinical meaning: Shaft, left femur, and what “unspecified” means

Understanding each component of the S72.302C description prevents laterality and anatomical site errors at the point of coding.

• Shaft (diaphysis): The fracture involves the mid-portion of the femur bone, not the femoral head, neck, or condyles. Shaft fractures are categorized separately from proximal femur (hip) fractures.
• Left: Laterality is explicit. S72.302 always refers to the left femur. The right femur equivalent is S72.301.
• Unspecified fracture type: The fracture pattern is not documented or clinically determinable. If the pattern is specified, a more specific code within the S72.3 subcategory may apply.
• Initial encounter: The patient is receiving active treatment for the injury. This includes emergency visits, surgical repair, and the full acute treatment phase.
• Open fracture type IIIA, IIIB, or IIIC: The skin is broken, exposing bone, and the wound severity meets Gustilo-Anderson type III criteria.

The “unspecified” qualifier says nothing about the quality of the documentation overall. It refers only to the fracture pattern subtype.

A fully documented open fracture with confirmed laterality, Gustilo type, and encounter type can still carry the “unspecified” descriptor. That happens whenever the surgeon has not characterized the fracture geometry.

Understanding the 7th character in fracture coding

The 7th character is the most consequential element of fracture coding in ICD-10-CM. For the S72.302 code family, it specifies the encounter type and, for open fractures, the Gustilo-Anderson wound classification. Using the wrong 7th character is one of the most common reasons orthopedic claims are denied or downcoded.

Consult the CDC/NCHS official ICD-10-CM web tool to verify the current 7th character assignments for the S72 code block each fiscal year.

The 7th character C applies exclusively to the initial encounter phase. Once the patient transitions to follow-up care after acute treatment, the 7th character changes to reflect healing status and Gustilo type.

Practices using claims management software that flags encounter-type mismatches can catch these errors before submission.

Gustilo-Anderson open fracture classification for ICD-10 coding

The Gustilo-Anderson classification is the standard system for grading open fracture severity. It was published in the Journal of Bone and Joint Surgery in 1976 and refined in 1984. ICD-10-CM’s 7th character choices for open fractures map directly to this classification.

Coders must not infer the Gustilo type from operative notes alone. The attending surgeon has to document the classification explicitly in the medical record.

All three type III subtypes share the same 7th character C for initial encounter coding. The distinction between IIIA, IIIB, and IIIC matters clinically for treatment planning, but ICD-10-CM groups them under a single 7th character. Practices running sports medicine software should make sure their note templates capture the subtype, because it drives the surgical plan.

Code hierarchy and sibling codes

ICD-10 code S72.302C sits within a structured hierarchy. Understanding the parent-to-child relationship helps coders select the right level of specificity and avoid non-billable placeholder codes.

The sibling codes share the same parent, S72.302, and differ only in the 7th character. That set covers closed initial encounters, subsequent encounters at each healing stage, and sequela.

A shaft fracture that fails to unite carries its own code, such as S72.309N. Open fractures elsewhere in the lower limb follow the same logic, as S82.191B shows for the tibia.

Initial encounter, subsequent encounter, or sequela

Choose the 7th character by what the provider is doing, not by how many visits the patient has had. Active treatment means an initial encounter character. Healing or monitoring means a subsequent encounter character. The most common error for femur fractures is applying a subsequent character during active treatment.

The AHA Coding Clinic and the ICD-10-CM Official Guidelines for Coding and Reporting are the definitive authority on encounter type.

“Initial encounter” does not mean the patient’s very first contact with a provider. The ICD-10-CM Official Guidelines tie it to active treatment instead.

A patient who returns to a different surgeon for definitive fixation still uses the initial encounter character. Running claim scrubbing before submission catches encounter-type mismatches while you can still fix them.

Documentation requirements for S72.302C

Claim denials for S72.302C almost always trace back to something missing from the medical record. The elements below must appear in the documentation before this code can be assigned. Structured medical forms make each one a required field rather than a habit.

• Confirmed laterality: The record must explicitly state “left femur.” Laterality cannot be assumed from procedural notes or imaging reports without a physician statement.
• Anatomical site: Documentation must confirm the fracture involves the shaft (diaphysis), not the neck, head, or distal femur.
• Open fracture confirmation: The attending or emergency physician must document that the fracture is open. That means the skin is broken and the bone is exposed or communicating with the wound.
• Gustilo-Anderson type III classification: The surgeon must state the Gustilo type as IIIA, IIIB, or IIIC in the operative report or wound assessment note. The ICD-10-CM guidelines require physician documentation for this classification. Coders cannot assign type III from wound size descriptions alone.
• Encounter type confirmation: The treating provider’s note must reflect that the patient is receiving active treatment, establishing the “initial encounter” qualifier.
• Fracture pattern (if available): If the pattern is documented as transverse, oblique, or spiral, a more specific code within S72.3 may be appropriate. “Unspecified” applies when the pattern is genuinely not documented.

Digital intake forms and note templates can prompt for laterality, fracture type, and Gustilo classification at the point of care. That cuts the back-and-forth between coders and treating teams. Use patient record management that surfaces these fields inside the encounter documentation workflow.

Common coding errors and how to avoid them

Payer audits for femur fracture codes frequently target these error patterns. Build them into your internal coding review, alongside the rest of your medical billing compliance checks.

• Submitting S72.302 without a 7th character: S72.302 is non-billable. Submitting it bare results in an automatic rejection. Every billable femur shaft fracture code carries a full 7th character.
• Wrong laterality: S72.302C is left femur only. S72.301C is the right femur equivalent. Most payers catch a laterality mix-up through edit checks.
• Using 7th character B instead of C: Type IIIA, IIIB, and IIIC fractures all require the C character. Using B, which applies to type I and II, misrepresents severity and can lead to underpayment.
• Applying the initial encounter character at follow-up visits: Active treatment ends when the patient moves to routine healing checks. At that point the 7th character changes from C to F.
• Inferring Gustilo type from a wound description: A coder might read “wound greater than 10 cm with periosteal stripping” in an operative note. Assigning type IIIB from that alone creates audit exposure. Query the surgeon when the Gustilo type is not documented.
• Omitting laterality on bilateral injuries: Bilateral femur fractures require separate codes for left and right. Do not use a single non-specific code to capture both.

Review coding accuracy regularly with the AAPC ICD-10-CM code lookup, and validate individual codes against the FY2026 entry for S72.302C. Pairing those checks with a standing denial management review catches systemic errors before they draw payer scrutiny.

Related ICD-10-CM codes for femur fractures

S72.302C sits within a family of femur fracture codes. Coders working across laterality, anatomical location, and encounter type should cross-reference the WHO ICD-10 browser for international context.

Always confirm the anatomical location in the surgeon’s operative report before selecting within the S72 family. Femoral neck fractures such as S72.036E are distinct from shaft fractures and carry different procedure codes. External fixation of an open femur fracture, for example, is billed under CPT code 20690.

How Pabau keeps femur fracture coding audit-ready

Most orthopedic practices assemble a femur fracture claim from three places. The operative report sits in one system, the coder works from a spreadsheet, and the claim goes out through a separate billing tool. Practice management software like Pabau puts all three in one record.

The diagnosis code attaches to the encounter rather than to a separate billing queue. Laterality, the Gustilo type, and the encounter phase are all fields on the note the surgeon signs. When the coder opens the record, everything the 7th character depends on is already there.

Claims then leave through our Claim.MD integration, the clearinghouse Pabau submits electronic claims through. A medical claims clearinghouse checks each claim against payer rules before it lands. Remittance comes back to the same patient record, so a denial on S72.302C points to the note that caused it.

Keep ICD-10 coding tied to the clinical record

Pabau links every diagnosis code to the encounter that produced it, so laterality, Gustilo type, and encounter phase stay in one place. That means fewer queries back to the surgeon and less denial rework.

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Conclusion

S72.302C is only as defensible as the surgeon’s note behind it. If the record names the left femoral shaft, calls the fracture open, and states a type III grade, the code holds up. Without an explicit grade from the surgeon, no amount of coder judgment will save it on audit.

So the work sits upstream of billing. Fix the note template and the query rate falls. Leave it alone and your team keeps chasing the same missing sentence, one claim at a time.

Want to see how the code, the note, and the claim stay together in one record? Book a demo and we’ll walk through it with your own orthopedic workflow.

Continue your research

Coding a shaft fracture that healed out of position? S82.499Q shows how the malunion 7th characters work in a long bone.

Moving a fracture patient onto a subsequent encounter code? S82.026R works through the switch at a follow-up visit.

Reporting a late effect of a femur injury? S72.124S covers sequela coding inside the same S72 family.

Documenting a type IIIC injury that ended in amputation? S78.121S handles the sequela of a traumatic thigh amputation.

Coding the soft tissue side of an open fracture? S86.921A covers muscle laceration in the lower leg.

Frequently asked questions