ICD-10 code S72.436C: Nondisplaced medial condyle fracture

Key takeaways

S72.436C is a billable ICD-10-CM code for a nondisplaced medial condyle fracture of an unspecified femur, initial encounter, open type IIIA, IIIB, or IIIC

The 6 in the sixth character means the record never named a side. Use S72.434C for the right femur and S72.435C for the left

The parent code S72.436 is not billable, and the Gustilo type in the operative note decides which 7th character you add

A fracture the record never describes as displaced or nondisplaced defaults to displaced, which rules S72.436C out

Pabau’s claims management integrates with Claim.MD to submit 837P claims, run eligibility checks, and process ERAs

ICD-10 code S72.436C reports a nondisplaced fracture of the medial condyle of an unspecified femur. It applies at an initial encounter for an open wound of Gustilo type IIIA, IIIB, or IIIC. The code is billable, so it clears a validity check on its own.

The sixth character is the one to read twice. That 6 means the record never named a side, and it does not mean the right femur. Read it as right and a high-acuity trauma claim lands on the wrong code.

What follows sets out the code’s structure, its 7th characters, the documentation each element needs, and the checks worth running before you submit.

S72.436C is billable, but only with its 7th character attached

Yes, you can bill it. S72.436C is a specific ICD-10-CM code, valid for electronic submission to Medicare, Medicaid, and commercial payers.

Its parent, S72.436, is not. Strip the C off the end and the claim is rejected before a human reads it.

Every character in S72.436C narrows the diagnosis one step

Read the code from left to right and each character records a single decision the chart has to prove. The diagram below pulls the seven characters apart, and shows why the sixth is the one that catches people out.

The code sits in ICD-10-CM Chapter 19, Injury, Poisoning and Certain Other Consequences of External Causes. Within that chapter it falls under category S72, fracture of femur. From there it narrows to S72.4, fracture of lower end of femur, and then to S72.43, fracture of medial condyle.

According to the Centers for Medicare and Medicaid Services (CMS), the S72 family covers all femur fractures coded under ICD-10-CM for fiscal year 2026.

Nondisplaced means the fragments never left their alignment

The medial condyle is the inner, weight-bearing prominence at the distal end of the femur, and it forms part of the knee joint. A nondisplaced fracture means the bone has cracked while the fragments stayed in their anatomical position.

That distinction drives the code. Displaced and nondisplaced fractures carry separate codes, different prognoses, and different surgical plans. Coding one as the other is a common audit trigger and a common denial cause.

If the note never says nondisplaced, the code defaults to displaced

Coders work from the treating clinician’s explicit wording. When the operative report or ED note reads nondisplaced, a nondisplaced code applies.

When the record says neither, the ICD-10-CM Official Guidelines default the fracture to displaced, so S72.436C is off the table.

The list below shows where each combination of displacement, laterality, and wound classification lands:

• Nondisplaced, side not documented, open IIIA/IIIB/IIIC: S72.436C
• Nondisplaced, right femur, open IIIA/IIIB/IIIC: S72.434C
• Nondisplaced, left femur, open IIIA/IIIB/IIIC: S72.435C
• Displaced, side not documented, open IIIA/IIIB/IIIC: S72.433C
• Nondisplaced, side not documented, closed or open type I/II: S72.436A (closed) or S72.436B (open type I or II)

Unspecified laterality says more about the chart than the patient

The sixth character of an S72.43x code carries laterality, and a 6 there means unspecified. Nobody arrives in an emergency department with a fracture of an unspecified femur. Somebody simply failed to write down which leg it was.

S72.436C is still valid and billable, so a claim carrying it will not reject for invalidity alone. The risk sits further downstream. Auditors read an unspecified code in a family that offers laterality as a sign the record was thin. Payers may also ask for the operative note before paying a high-acuity open fracture claim.

Take a motorcyclist brought in after a collision. The ED note records an open distal femur fracture with a 12 cm wound.

The operative report describes a nondisplaced medial condyle fracture and type IIIA soft tissue injury, and never names a side. Radiology does name one, and it says left. The code is S72.435C, and S72.436C would be wrong.

So before you settle on the unspecified code, answer three questions:

• Does any part of the record name a side? Radiology reports, anesthesia records, and nursing notes often state right or left even when the operative report does not.
• Can the provider still be queried? If the clinician is reachable and the encounter is open, a query is faster than an appeal. A documented answer moves you to S72.434C or S72.435C.
• Is the record genuinely closed to correction? Transferred patients and records that arrive incomplete from another facility are the situations where an unspecified code is the honest choice.

Practices that track unspecified codes as a metric usually find them clustered around a handful of templates or a handful of clinicians. That makes the fix a documentation change rather than a coding change.

Gustilo types IIIA, IIIB, and IIIC share a single 7th character

All three type III subtypes map to the same 7th character, so the grading matters more clinically than it does on the claim. Gustilo-Anderson is the primary grading system for open fractures.

Ramon Gustilo and John Anderson sorted them into three types by wound size, soft tissue damage, and vascular injury. Type III then splits into IIIA, IIIB, and IIIC.

So ICD-10-CM folds IIIA, IIIB, and IIIC back into one 7th character, C, at the initial encounter. Clinical management does not work that way, since IIIB and IIIC carry far higher amputation risk and consume more resources.

For coding, though, the subtype does not change the character. The documentation only has to confirm the fracture is Gustilo type III.

The wound classification decides between A, B, and C

Closed fractures take A at the initial encounter. Open fractures then split by Gustilo type. Type I or II takes the B character, and type IIIA, IIIB, or IIIC takes the C character. AAPC coding guidance lists this as one of the most common denial triggers on femur fracture claims.

A fracture with no documentation of open or closed status defaults to closed under the official guidelines. When the record is ambiguous, code closed and attach a documentation query to the chart before billing.

Submitting an open-fracture code without operative documentation of the wound creates audit exposure. That matters most for Gustilo III codes, where the paired CPT procedures reflect much higher resource use.

The 7th character tracks the phase of care, not the injury

S72.436C carries C in the 7th position, and that character reports where the patient sits in treatment. The S72.436 family uses 16 possible 7th characters, running A through S with I, L, and O omitted.

Each one combines an encounter type, a wound classification, and a healing status. The table below lists all 16, per the CDC/NCHS official ICD-10-CM code tool.

Use C only for the initial encounter, meaning the period when the patient is under active treatment for the fracture. That covers the emergency department visit, the operative episode, and any inpatient days tied to fracture management.

The character stays C throughout that phase, even when a different provider sees the patient inside the same episode.

The subsequent encounter phase begins once definitive treatment is finished and the patient returns for follow-up, wound care, or rehabilitation.

Characters D through R cover that phase, chosen by healing status. Sequela, character S, applies to a late effect that develops after the fracture itself has healed.

The S72.43 family splits six ways before the 7th character

Laterality and displacement are settled one character earlier, in the sixth. S72.43 covers every fracture of the medial condyle of the femur, and it splits into six subcategories.

Three cover displaced fractures and three cover nondisplaced ones, each with a right, left, and unspecified option. Checking your code against this grid before you submit is the fastest way to catch a laterality error.

The trap is assuming the sequence restarts every third value, which is how S72.436C gets misread as a right-femur code. None of these six subcategories is billable on its own, and neither are the parent codes S72.43, S72.4, and S72.

Each one needs a 7th character first. The same six-way split repeats through the rest of the distal femur codes, and the ICD-10-CM code index covers those families one by one.

Excludes1 stops a claim that also reports a thigh amputation

S72.436C inherits every instructional note published above it in the tabular list. So read the category and subcategory notes, not just the code description.

• Excludes1 at S72: traumatic amputation of hip and thigh (S78.-). An Excludes1 note means the two conditions cannot be coded together on the same encounter.
• Excludes2 at S72: fracture of lower leg and ankle (S82.-), fracture of foot (S92.-), and periprosthetic fracture of prosthetic implant of hip (M97.0-). An Excludes2 note means the condition is not part of S72, but a patient can have both, so you may code both.
• Excludes2 at S72.4: physeal fracture of lower end of femur (S79.1-). Pediatric growth plate injuries at the distal femur belong in S79.1, not S72.4.
• 7th character requirement at S72: the appropriate 7th character must be added to every code in category S72. That is what makes S72.436 unbillable and S72.436C billable.

The Excludes1 note is the one that generates edits at the payer. A claim carrying both S72.436C and an S78 traumatic amputation code for the same limb contradicts itself, and the payer will treat it that way.

Six elements the chart must show for S72.436C to hold up

A code this specific holds up only when each element of its description appears somewhere in the chart.

Orthopedic and rehabilitation teams inherit that record from acute care, so what the ED and the operating room wrote decides what can be billed later.

• Laterality: S72.436C is the code you use when the record does not name a side. If any note states right or left femur, move to S72.434C or S72.435C instead.
• Displacement status: the operative or radiology report has to use the word nondisplaced. Silence on displacement defaults the fracture to displaced.
• Open versus closed: the wound must be classified as open in the ED or operative note. Skin penetration, contamination, or wound communication with the fracture site should be described.
• Gustilo classification: the operative report must document the Gustilo type. A general statement such as “type III open fracture” is adequate for ICD-10-CM, since the code groups all three subtypes.
• Encounter type: the note should make clear whether this is the initial active-treatment encounter or a follow-up visit, which supports the 7th character.
• Fracture mechanism: an external cause code requires documentation of how the injury happened, such as a fall, a motor vehicle collision, or a sports injury.

The external cause code is sequenced second, never first

ICD-10-CM Official Guidelines Section I.C.19 asks for an external cause code alongside a trauma code such as S72.436C. That code comes from the V, W, X, or Y blocks and describes the mechanism of injury.

The fracture code is sequenced first, as the principal diagnosis on inpatient claims or the first-listed diagnosis on outpatient claims. The external cause code follows it.

CPT 27514 is the procedure most often paired with this code

CPT selection for an open medial condyle fracture follows the operative approach, the fixation method, and whether vascular repair was needed.

S72.436C describes the diagnosis, and the CPT code describes the procedure. That choice always belongs to the treating clinician and coder, working from the operative note.

Pairing an unspecified-laterality diagnosis with a lateralized procedure creates a visible inconsistency on the claim. Distal femur fracture procedures normally carry an RT or LT modifier.

A claim that names a side on the CPT line while leaving the diagnosis unspecified invites a request for records. If the operative note supports a side, the diagnosis code should carry it too.

Run these checks before the claim leaves the practice

Five checks catch most of what goes wrong on an S72.436C claim, and together they take far less time than an appeal.

• Side: search the radiology, anesthesia, and nursing notes. One mention of right or left moves you to S72.434C or S72.435C.
• Displacement: confirm the word nondisplaced appears in the operative or radiology report.
• Wound: confirm the note calls the fracture open and records a Gustilo type of III.
• Phase: confirm the visit sits inside active treatment. A follow-up visit takes a subsequent-encounter character instead.
• Mechanism: confirm a V, W, X, or Y code describes how the injury happened, sequenced after the fracture code.

After that the claim travels as an 837P file to the clearinghouse, which screens format and eligibility before the payer sees it. Payer edits then test whether the diagnosis, the procedure, and the modifiers agree with each other.

A clean claim clears both layers on the first pass. On a Gustilo III case that usually comes down to documentation rather than code choice.

Where coders go wrong on the S72.43 family

The most frequent error is the one this article opened with, reading the 6 as right. Open femur fractures are among the highest-acuity trauma codes in ICD-10-CM, and their specificity makes them error-prone.

Tracking denials by code inside software for orthopedic billing shows which of the mistakes below a practice keeps repeating.

• Reading the 6 as “right”: assigning S72.436C to a documented right femur fracture. The right-femur nondisplaced code is S72.434C, and the left-femur code is S72.435C.
• Defaulting to unspecified: using S72.436C when the chart does name a side elsewhere. Check radiology and nursing notes before you accept the unspecified code.
• Displaced versus nondisplaced confusion: assigning S72.436C when the record documents a displaced fracture. Displaced medial condyle fractures use the S72.431 to S72.433 range.
• Incorrect Gustilo subtype: using the C character when the operative note documents Gustilo type I or II. Those take the B character instead.
• Billing the parent code: S72.436 without a 7th character is not billable, and a claim carrying it is rejected automatically.
• Wrong encounter type on follow-up: keeping S72.436C on post-operative physio or wound-check visits. Once active treatment ends, move to the subsequent-encounter character that matches healing status.
• Missing external cause code: omitting the V, W, X, or Y code that describes the mechanism. Payer edits and CMS guidance expect one on trauma claims.

How Pabau keeps the note and the claim on the same code

In most orthopedic and trauma practices, the diagnosis is captured once in the clinical note and then typed again into the billing system.

Every re-key is a chance for a laterality to flip or a 7th character to drop, and nobody notices until the remittance arrives weeks later.

Pabau, a practice management platform for healthcare practices, keeps the record and the claim in one place. The diagnosis recorded at the encounter travels with the patient into billing, and eligibility runs before the visit rather than after it.

Claims go out to Claim.MD as 837P files from the same system that holds the note. ERAs come back into that record, so the person who coded the encounter can see how it was paid.

An open Gustilo III femur fracture spans the ED, the operating room, and months of rehabilitation. Across an episode that long, continuity is what separates a clean claim from an appeal.

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Pabau integrates with Claim.MD to submit 837P claims, run eligibility checks, and process ERAs for orthopedic and trauma practices. See how the claims workflow handles an open fracture case.

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Conclusion

S72.436C is precise on three points and silent on a fourth. It fixes the fracture as nondisplaced, the wound as Gustilo type III, and the encounter as the initial one. Laterality is the point it leaves open, because the record left it open. Treat that silence as a prompt rather than a default.

If any note names a side, S72.434C or S72.435C is the code you owe the payer. If none does, a query is usually faster than an appeal, and it leaves a better record behind for the next encounter.

Book a demo to see how Pabau handles an open fracture claim from the operative note through to the remittance.

Continue your research

Coding another femur fracture with a 7th character? ICD-10 code S72.352J works the same 7th character logic on a left femur fracture with delayed healing.

Want to see how the claim reaches the payer? What is a medical claims clearinghouse? explains the 837P submission path from practice to payer.

Chasing a denial on a trauma claim? Denial codes in medical billing maps the most common CARC codes and the documentation that clears them.

Need to read the payer’s answer? What is electronic remittance advice (ERA)? shows how an 835 file reports an adjudication decision back to the practice.

New to the billing cycle? What is medical billing? covers the full path from patient registration through to payment posting.

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