ICD code S72.091Q – Right femur open fracture with malunion

Key takeaways

S72.091Q is billable for FY2026 and valid in all HIPAA-covered transactions from October 1, 2025.

The 7th character Q encodes three facts at once: subsequent encounter, open fracture type I or II, and malunion.

Gustilo-Anderson grade type I or type II must be documented by the treating physician to support this code.

A type IIIA, IIIB, or IIIC open fracture with malunion takes character R, so grade and healing status are read together.

Pabau keeps the 7th character consistent from the clinical note through to the submitted claim.

ICD-10 code S72.091Q: Definition, billability, and FY2026 validity

ICD-10 code S72.091Q is a valid, billable ICD-10-CM diagnosis code in the 2026 edition, effective October 1, 2025, and accepted in all HIPAA-covered transactions. According to the CMS ICD-10-CM code files, S72.091Q sits within Chapter 19, covering injury, poisoning and certain other consequences of external causes. Within that chapter it falls under category S72, fracture of femur.

The full official descriptor is: Other fracture of head and neck of right femur, subsequent encounter for open fracture type I or II with malunion. Every word in that descriptor carries coding weight.

Breaking down the S72.091Q code structure

Each character position in S72.091Q carries a specific clinical meaning. Coders who understand the anatomy of the code are less likely to select a sibling code by mistake.

The 5th character 9 places this fracture in the “other” subcategory under S72.09. That subcategory sits alongside several more specific siblings in the S72.0 range, each with its own 5th character.

• A fracture of the head of the femur takes S72.05 or S72.06.
• An unspecified intracapsular fracture of the femur takes S72.01.
• A midcervical fracture of the femur takes S72.03.
• A fracture of an unspecified part of the femoral neck takes S72.00.

Read the operative or clinical note for the exact anatomical region before settling on S72.09. The “other” subcategory is correct only when the documented site does not match one of the named siblings above.

What the 7th character Q encodes

The 7th character Q encodes three simultaneous clinical facts. The encounter is a subsequent (follow-up) visit, and the original fracture was open and graded Gustilo-Anderson type I or type II. The fracture has since healed with malunion. Each of those facts requires physician documentation to support the code.

Gustilo-Anderson open fracture classification

The Gustilo-Anderson classification grades open fractures by wound size, degree of soft tissue injury, and vascular involvement. ICD-10-CM splits those grades into two 7th-character groups: type I or II in one group, and type IIIA, IIIB, or IIIC in the other. S72.091Q belongs to the first group, so the note must place the original fracture at type I or type II.

Types I and II share one set of 7th characters, and Q is the malunion member of that set. A fracture documented as Gustilo type IIIA, IIIB, or IIIC maps to a different set. There the malunion outcome takes character R rather than Q.

Malunion vs nonunion: Key coding distinctions

Malunion means the fracture has healed but in an abnormal position. Nonunion means the healing process has stalled and bone union has not occurred. These are mutually exclusive outcomes, and the 7th character distinguishes them precisely. The grid below plots every subsequent-encounter character for S72.091 against the two facts that select it.

• 7th character Q: subsequent encounter, open fracture type I or II, with malunion (healed in poor alignment)
• 7th character M: subsequent encounter, open fracture type I or II, with nonunion (healing has failed)
• 7th character E: subsequent encounter, open fracture type I or II, with routine healing
• 7th character R: the same malunion outcome, but where the original fracture was graded type IIIA, IIIB, or IIIC
• 7th character N: subsequent encounter, open fracture type IIIA, IIIB, or IIIC, with nonunion

A radiographic report confirming the malunion finding is the strongest documentation for this code. A note reading “fracture healing, mild displacement” states no malunion conclusion, so it may not survive audit.

Complete 7th character table for S72.091

The full set of 7th character options for S72.091 covers initial encounters, subsequent encounters by fracture openness, and healing outcomes. Subsequent encounter codes (D through R) are the ones most commonly used in orthopedic follow-up billing.

S72.091Q in context: Parent and related codes

S72.091Q belongs to a hierarchy of increasingly specific codes. Understanding the full code tree helps coders navigate to the correct level and identify sibling codes when laterality or fracture subtype differs.

The CDC/NCHS ICD-10-CM tool lets coders browse the full S72 hierarchy in tabular and index views. Our diagnostic code library covers the same codes with the billing detail set out beside each one.

Use S72.099Q (unspecified femur) only when laterality is genuinely not determinable from the documentation. Payers flag it in medical necessity reviews when a laterality-specific code could reasonably have been assigned.

Approximate synonyms and clinical terminology

The following clinical terms and phrases are recognized as synonymous with S72.091Q. These are the terms most likely to appear in operative notes, radiology reports, and discharge summaries when this code applies.

• Right femoral head fracture, subsequent encounter, open type I with malunion
• Right femoral neck fracture (other type), follow-up, open Gustilo II, healed with malunion
• Compound fracture right proximal femur, subsequent visit, type I or II, malunited
• Open fracture right hip, subsequent encounter, Gustilo grade 1 or 2, malunion
• Malunited right femoral head and neck fracture, subsequent, open type I or II
• Right proximal femur open fracture follow-up, low-grade open injury, healed malunion

These synonym phrasings appear most often in orthopedic surgery discharge summaries and radiology follow-up reports. When the note uses language from this list without stating the ICD-10 code, the coder must confirm laterality and healing status first. The physician note has to support every component of the selected code.

Documentation requirements for S72.091Q

Five elements must be present in the physician’s documentation to support S72.091Q. Missing any one of them shifts the code to a less specific or incorrect alternative.

• Fracture site: “head and neck of femur” or “proximal femur” in the subcategory S72.09 range (not femoral shaft, subtrochanteric, or intertrochanteric)
• Laterality: right femur explicitly stated (left femur maps to S72.092Q; unspecified maps to S72.099Q)
• Open fracture type: Gustilo-Anderson type I or type II must be documented. A bare “open fracture” without a grade, or a type III grade, will not support this code.
• Encounter type: this is a subsequent (follow-up) encounter, not the initial treatment visit and not a sequela
• Healing status: malunion must be explicitly stated or confirmed radiographically in the record

Section I.C.19 of the FY2026 CMS ICD-10-CM Official Guidelines for Coding and Reporting addresses fracture coding directly. It requires the 7th character to reflect the fracture’s status at each encounter. A fracture coded with routine healing at an earlier visit may be updated to malunion at a later one. That switch holds as long as imaging confirms the outcome and the physician’s note supports it.

Related CPT codes for hip and femur fracture procedures

S72.091Q is a diagnosis code and must be paired with a procedure code (CPT) that reflects the service rendered at the encounter. Revision surgery after a malunited proximal femur fracture is often billed under 27130, so the diagnosis and the procedure have to describe the same encounter.

The CPT codes below are the ones most commonly billed alongside S72-category diagnosis codes in orthopedic settings. Verify every code and payment amount against the current AAPC ICD-10-CM and CPT crosswalk resources and the CMS Physician Fee Schedule.

Billing and reimbursement considerations

S72.091Q is valid for Medicare, Medicaid, and commercial payer claims under HIPAA-covered transactions. This is a subsequent encounter code for a high-acuity open fracture with a complication, so payers may request supporting documentation during claims review. Sending the radiology report with the first submission usually settles that request before it is made.

Submitting S72.091Q through a clearinghouse catches code-level edits before the claim reaches the payer. Practice management software like Pabau sends electronic claims through Claim.MD, its US clearinghouse partner. That route supports CMS-1500 and 837P submissions and validates the ICD-10 code before it leaves the practice.

Validation matters most when one patient returns for several follow-up encounters. Each healing stage carries its own 7th character, so the same fracture can be billed under E, then H, then Q across a single recovery.

Pabau’s claims management software also returns electronic remittance advice (ERA) through Claim.MD’s 835 process. Billing teams match payments and read denial reasons at the claim line level. Tracked across a run of S72 claims, those line-level reasons show which 7th character a given payer keeps rejecting.

Do not assert specific reimbursement dollar amounts for S72.091Q; actual payment rates vary by payer contract, geographic adjustment factor, and CMS fee schedule updates. Refer to the CMS Physician Fee Schedule and individual payer contracts for current reimbursement rates.

Common coding mistakes and how to avoid them

Six errors account for most claim rejections and audit findings on S72.091Q. Each one starts at a different point, some in the clinical note and some in the billing workflow.

• Using character A (initial encounter) at a follow-up visit: Character A applies only when the patient is receiving active treatment for the injury. Orthopedic follow-up visits after initial surgical treatment use subsequent encounter characters (D through R). This is the most common 7th character error in fracture coding.
• Omitting the Gustilo-Anderson grade: A note that states “open fracture” without specifying the grade cannot support this code. Character Q requires type I or type II. The coder should query for the grade rather than guess.
• Coding a type III fracture as Q: A malunited open fracture graded IIIA, IIIB, or IIIC takes character R instead. Swapping R and Q is the most common severity error on S72.091 claims.
• Confusing malunion with nonunion: Malunion (Q) means the fracture healed in poor alignment. Nonunion on the same type I or II fracture takes M, and the fracture has not healed at all. Radiology reports usually make the distinction clear; clinical notes sometimes use informal language that requires clarification.
• Missing laterality: Assigning S72.099Q (unspecified femur) when the operative report clearly documents “right femur” is a specificity downcode. Payers increasingly flag this during medical necessity edits.
• Sequela (S) vs subsequent encounter: Sequela codes apply to late effects that arise as a new condition after the fracture has healed. Ongoing management of an unhealed or malunited fracture still uses subsequent encounter characters, not S.

Practices that build these six checks into the documentation workflow catch the errors before submission rather than after denial. A recurring 7th character rejection shows up quickly once denials are grouped by reason code. The fix then belongs in the clinical note, not in the billing queue.

How Pabau supports accurate ICD-10 diagnostic coding

Orthopedic billing teams using Pabau can attach ICD-10 diagnosis codes directly to clinical notes at the point of care. The coder then receives a pre-populated encounter record carrying the treating physician’s own diagnosis selection. This reduces transcription-based 7th character errors that occur when coders reconstruct the clinical picture from a scanned paper note.

Pabau’s built-in ICD-10 search supports code-string lookup (S72.091Q) and plain-language search alike. Clinicians find the correct code without memorizing the full hierarchy.

Because the diagnosis, the claim, and the remittance sit in one system, the previous encounter’s 7th character is visible when the next one is coded. A coder updating E to Q can see what was billed last time instead of rebuilding the history from scans.

Accurate ICD-10 coding starts with the right clinical documentation

Pabau helps orthopedic and musculoskeletal practices capture the clinical detail needed to support specific diagnosis codes like S72.091Q at every encounter.

Book a demo

Conclusion

Two readings of the chart carry almost all the risk on S72.091Q. The Gustilo-Anderson grade separates Q from R. The healing outcome separates Q from M, which is nonunion, and from E, which is routine healing. A note that settles only one of the two will not support this code.

The practical move is to settle both at the visit rather than at the coding desk. Query the treating physician while the imaging is still in front of them, and the 7th character stops being a judgment call weeks later. Coders inherit a decision instead of making one.

Pabau carries the grade and the healing outcome from the clinical note into the claim itself. To see how the platform handles fracture coding across a run of follow-up encounters, book a demo.

Continue your research

Need to understand how claims move from coding to payment? Pabau’s Claim.MD clearinghouse guide explains how electronic claim submission works for US orthopedic practices.

Wondering how to reduce open fracture claim denials? Denial management in healthcare covers the most common denial patterns and how to address them at the documentation level.

Want fewer rejections on first submission? Submitting a clean claim sets out what payers check before a claim is accepted.

Frequently asked questions