ICD-10 code S52.271A: Monteggia’s fracture of right ulna

Key takeaways

S52.271A is a billable ICD-10-CM code for Monteggia’s fracture of right ulna, initial encounter for closed fracture. It is valid for FY2026.

The 7th character ‘A’ signals active treatment, not merely the first-ever visit. A change of provider mid-treatment still uses ‘A’.

A Monteggia fracture needs a second diagnosis code for the radial head dislocation. Omitting it is a common documentation error that triggers claim scrutiny.

CPT 24620 and 24635 are the two procedure codes titled for a Monteggia fracture dislocation at the elbow, so check those first.

Practice management software like Pabau lets orthopedic teams attach ICD-10 codes to the encounter note, so coding errors surface at the point of care.

ICD-10 code S52.271A is the billable diagnosis code for Monteggia’s fracture of the right ulna, initial encounter for closed fracture. The injury pairs a proximal ulnar shaft fracture with a dislocation of the radial head. One seven-character code carries laterality, fracture status, and encounter type.

S52.271A became effective October 1, 2025, under the FY2026 edition of the CDC/NCHS ICD-10-CM classification. Orthopedic surgeons, emergency physicians, and sports medicine providers assign it at presentation and through active surgical management.

Rehab teams working in a physical therapy EMR pick the injury up later, under a subsequent-encounter character.

Quick reference: S52.271A at a glance

What is a Monteggia fracture?

A Monteggia fracture combines two injuries at once. The first is a fracture of the proximal ulnar shaft. The second is a dislocation of the radial head at the proximal radioulnar joint. The two always occur together. Treating the ulnar fracture without addressing the radial head leads to long-term elbow instability.

Laterality is essential for coding. S52.271A specifies the right ulna because payers require anatomic precision on orthopedic fracture claims. An unspecified or left-sided code against a documented right-sided injury creates a mismatch that auditors flag.

The Bado classification, Types I through IV, describes the direction of radial head dislocation relative to the ulnar fracture apex. S52.271A does not require a Bado type on the claim. Capturing it in the operative note still supports coding specificity and surgical planning.

ICD-10-CM code hierarchy and classification

Knowing where S52.271A sits in the code tree helps coders find related codes and avoid picking a parent that is not billable on its own.

S52.271 without a 7th character is not billable, so a truncated code is a guaranteed rejection. Carry the full seven characters onto the claim every time. The same hierarchy rules govern every code in the S52 block.

Understanding the 7th character extension for S52.271

The 7th character is where most Monteggia coding errors happen. It records whether the patient is in active treatment, healing follow-up, or being seen for a complication or late effect.

Per CMS ICD-10-CM coding guidelines, the character reflects the encounter type rather than the number of episodes.

Those eight characters cover the closed-fracture pathway. Open fractures carry their own subsequent-encounter set, which pairs a healing status with the Gustilo grade. Codes such as S82.016B and S82.121Q show the same pattern at work elsewhere in the fracture chapter.

One misconception is worth clearing up. “Initial” does not mean the first calendar visit. It means the patient is still in active treatment for the injury. A patient transferred to a specialist three weeks post-injury is still in active treatment, so the specialist’s first encounter also uses ‘A’.

When to use S52.271A vs related codes

Three variables drive code selection inside the S52.271 family: laterality, open vs closed fracture, and encounter type. The table below maps the common presentations to the right code. Codes like S83.016A use the same three-variable logic in the joint dislocation block.

Avoid S52.279A unless the provider genuinely cannot document laterality. Payers scrutinize unspecified codes on orthopedic fractures, and an audit will flag a right-arm X-ray paired with an unspecified code.

Related ICD-10-CM codes for Monteggia fracture

A Monteggia fracture nearly always involves a concurrent radial head dislocation. ICD-10-CM guidelines direct coders to report both injuries when a dislocation accompanies a fracture in the same segment. The radial head component sits in the S53 block, which covers dislocation and sprain of the elbow.

A true Monteggia carries a full dislocation, so one of the S53.0x4A codes usually applies. Save the subluxation codes for partial displacement that the provider describes that way.

• S53.004A — Unspecified dislocation of right radial head, initial encounter
• S53.014A — Anterior dislocation of right radial head, initial encounter
• S53.024A — Posterior dislocation of right radial head, initial encounter
• S53.001A — Unspecified subluxation of right radial head, initial encounter
• S53.011A — Anterior subluxation of right radial head, initial encounter
• S53.021A — Posterior subluxation of right radial head, initial encounter
• S52.272A — Monteggia’s fracture of left ulna, initial encounter for closed fracture
• S52.279A — Monteggia’s fracture of unspecified ulna, initial encounter for closed fracture
• S52.271D — Subsequent encounter, routine healing (right, closed)
• S52.271K — Subsequent encounter, nonunion (right, closed)
• S52.271S — Sequela of Monteggia fracture of right ulna

When the note documents a radial head dislocation, submit both S52.271A and the matching S53 code. Sending S52.271A alone is under-coding, and it can support a lower evaluation and management (E&M) level than the case deserves.

Documentation requirements for S52.271A

The provider note must confirm four elements before a coder can defensibly assign S52.271A. Missing any one of them leaves an unsupported code that carries audit risk. Good documentation compliance habits include structured note templates that capture these fields at the point of care.

1. Laterality confirmed as right: The note must state “right ulna” or “right forearm.” An imaging report naming the right arm counts as supporting documentation.
2. Fracture type identified as Monteggia: The provider must name the injury or describe the combined ulnar fracture and radial head dislocation. Generic “forearm fracture” language needs a query.
3. Closed fracture confirmed: The note must say “closed fracture” or describe no skin breach over the site. Query the provider if wound status is ambiguous.
4. Active treatment documented: The note must show the visit relates to active treatment. Operative reports, ED notes, and specialist consults all qualify. Routine healing visits move the code to ‘D’.

Structured clinical encounter records keep these four elements consistent across providers and encounter types. Practices with dedicated injury documentation fields in the chart send far fewer coder queries.

Coding guidelines: Initial vs subsequent vs sequela encounters

The ICD-10-CM Official Guidelines for Coding and Reporting, Section I.C.19.c, define the encounter types for fracture codes. The distinction rests on clinical status, not visit count.

The sequela scenario needs particular attention. Official guidelines say to report the residual condition first, for example M19.121 for post-traumatic osteoarthritis of the right elbow, then the fracture sequela code S52.271S. Using S52.271S as the principal diagnosis with no residual condition code is incorrect.

Associated CPT codes for Monteggia fracture treatment

Billing a Monteggia claim means pairing S52.271A with the right CPT procedure code. Two codes are titled for this exact injury: 24620 for closed treatment and 24635 for open treatment.

Orthopedic and sports medicine software platforms flag mismatched CPT-to-ICD pairings before submission.

Verify current codes against the AAPC CPT code lookup before billing. CPT codes change annually, and the AMA CPT manual is the authoritative source for the current year. Local payer medical necessity policies may ask for extra documentation on top of these pairings.

ICD-9-CM crosswalk for S52.271A

Legacy billing systems and coordination-of-benefits work occasionally call for the ICD-9-CM equivalent of S52.271A. Under the CMS General Equivalence Mappings (GEMs), that equivalent is 813.03, closed fracture of the proximal end of the ulna, Monteggia’s fracture.

• Forward map (ICD-9 to ICD-10): 813.03 maps to S52.279A, because the ICD-9 code carries no laterality
• Backward map (ICD-10 to ICD-9): S52.271A maps to 813.03
• Limitation: 813.03 covered both right and left Monteggia fractures, so side information is lost in one direction

For crosswalk verification, work from the CDC’s ICD-10-CM files, which host the official GEMs data. The mapping stays approximate because ICD-9-CM lacked the laterality and open/closed detail built into S52.271A.

How to use ICD-10 code S52.271A in practice management software

Practice management software like Pabau lets orthopedic and multi-specialty practices attach ICD-10 codes to the encounter note during or straight after the consultation. Pabau’s claims management software searches ICD-10 codes at the point of care. It links the diagnosis to the treatment plan and hands the whole thing to billing.

Structured digital medical forms capture the four S52.271A requirements at intake: laterality, fracture type, open or closed status, and encounter classification. Practices that make these mandatory fields on the injury assessment form see fewer coder queries and lower first-pass denial rates.

Digital intake forms built around orthopedic injury classification mean the provider enters the detail once. The coder then has everything needed to pick the right 7th character, with no follow-up questions and no pause in the billing cycle.

Reduce coding errors at the point of care

Pabau lets your team attach ICD-10 codes to encounter notes, link diagnoses to treatment plans, and push clean claims. See how orthopedic and sports medicine practices run the whole billing workflow in one platform.

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Conclusion

S52.271A is only half the picture. The code names the ulnar fracture, and the S53 dislocation code names the other half of the injury the surgeon actually treated. Submit one without the other and the claim understates the case.

So build the habit at the note rather than at the claim. Capture laterality, wound status, and dislocation direction while the patient is in front of you. The coder then never has to guess, and the 7th character takes care of itself.

That is a documentation problem before it is a billing problem. Book a demo to see how Pabau links diagnosis codes to encounter notes for orthopedic and sports medicine teams.

Continue your research

Handling a malunion at a later visit? S82.121Q walks through the subsequent-encounter characters that combine healing status with open fracture type.

Coding a joint dislocation on its own? S83.016A applies the same laterality and encounter rules inside the dislocation block.

Reporting the late effects of an injury? S81.009S explains how the sequela character works and which code gets sequenced first.

Billing a closed reduction with manipulation? 23605 breaks down the documentation a closed fracture treatment claim needs to hold up.

Frequently asked questions