ICD-10 code S52.692R: Other fracture of lower end of left ulna

Key takeaways

ICD-10 code S52.692R covers other fracture of the lower end of the left ulna. It applies to a subsequent encounter, open fracture type IIIA, IIIB, or IIIC, with malunion.

S52.692R is a fully billable ICD-10-CM code valid for FY2026 and accepted in all HIPAA-covered transactions.

The 7th character R is required. S52.692 on its own is non-billable and payers will reject it.

Do not treat H as a substitute for R, because S52.692H means an open type I or II fracture with delayed healing.

Malunion must be attested by the treating physician. Coders cannot infer it from an imaging report alone.

ICD-10 code S52.692R is a billable diagnosis code for other fracture of the lower end of the left ulna. It applies to a subsequent encounter for an open fracture of Gustilo-Anderson type IIIA, IIIB, or IIIC that has healed with malunion.

Only the letter R carries all three of those facts at once. Change the letter and you change the injury, the encounter type, or the healing outcome the claim reports.

This reference covers every valid 7th character for S52.692, the Gustilo-Anderson classification criteria, and the malunion versus nonunion distinction.

It also covers documentation requirements and the CPT codes most often paired with this diagnosis. Whether you use claims management software or manual workflows, the tables below let you check your selection before you submit.

ICD-10 code S52.692R: Quick reference

S52.692R is a valid, billable ICD-10-CM diagnosis code effective for FY2026. According to the CDC/NCHS ICD-10-CM web tool, the code carries no age or sex exclusions. It is accepted in every HIPAA-covered transaction.

What does S52.692R mean? Full code description

Every element of this code carries clinical weight. Misreading any component produces a coding error that can trigger a denial or an audit finding.

• S52: Fracture of forearm. This is the ICD-10-CM category covering all fractures of the radius and ulna.
• S52.6: Fracture of lower end of ulna. The “6” subcategory isolates the distal ulna, distinguishing it from shaft or proximal ulna fractures.
• S52.69: Other fracture of lower end of ulna. The “9” descriptor covers fracture types that do not fit the more specific subcategories within S52.6.
• S52.692: Other fracture of lower end of left ulna. Laterality is explicit and this code is left-side only. Right ulna fractures use S52.691, and unspecified laterality uses S52.699.
• 7th character R: Subsequent encounter for open fracture type IIIA, IIIB, or IIIC with malunion. This single character encodes three clinical facts at once. It carries the encounter type, the Gustilo-Anderson tier, and the healing complication.

Without the 7th character, S52.692 is non-billable. Payers reject it as an incomplete code. The 7th character is not optional, and it is structurally required for claim submission.

S52.692 7th character options: Full table

S52.692 supports sixteen 7th characters. Each one combines an encounter type, a fracture openness, and a healing outcome. The table below shows every valid extension. Choosing the wrong letter is one of the most common sources of claim denial for distal left ulna fracture encounters.

ICD-10 code S52.692R uses the 7th character R, the last letter in the subsequent-encounter run. The alphabet is not continuous here. ICD-10-CM fracture extensions skip I, L, and O so that they cannot be misread as the numerals 1 and 0.

Read the table as a grid rather than a list. There are four healing outcomes: routine healing, delayed healing, nonunion, and malunion. Each outcome has one letter for each of the three fracture types. Malunion runs P for closed, Q for open type I or II, and R for open type III.

S52.692R vs S52.692H vs S52.692J: The mix-up that costs claims

These three codes sit within a few letters of each other and describe different patients. Several coding cheat sheets circulate with them transposed, so verify against the tabular list rather than a summary. The table below shows what actually separates them.

Two questions settle the choice. Did the operative note record a Gustilo type III, or a type I or II? Has the bone united in a bad position, or has it simply not finished healing? Answer both from the chart and only one letter survives.

The same R logic runs through the neighboring radius codes, where S52.356R marks an open type III malunion. Forearm injuries often damage both bones, so a single encounter can need one R code for each.

Gustilo-Anderson open fracture classification: Types IIIA, IIIB, and IIIC

The Gustilo-Anderson classification determines which 7th character applies to open fractures. Ramon Gustilo and John Anderson published it in 1976 and expanded it in later work.

It grades open fractures by wound size, contamination, periosteal stripping, and vascular injury. Type determination is an intraoperative judgment, so coders rely entirely on the surgeon’s documented classification.

All three subtypes share the same 7th character pool because ICD-10-CM treats IIIA, IIIB, and IIIC as a single coding tier. The distinction between subtypes still matters for surgical planning and prognosis.

For coding purposes, documenting any of the three satisfies the same requirement. What cannot be omitted is the type III designation itself.

Malunion vs. nonunion vs. delayed healing in ICD-10 fracture coding

The healing outcome encoded in the 7th character is where coders most often go wrong on subsequent encounter claims. Routine healing, delayed healing, nonunion, and malunion are clinically distinct states. Each one takes a different letter, so the wrong outcome changes the code entirely.

Every outcome in this table has a Gustilo III letter. There is no missing option, and no reason to fall back on a closed-fracture character when the chart documents an open type III injury. The closed equivalents are D, G, K, and P, in the same order.

The critical distinction for S52.692R is that malunion means the bone has united, but in the wrong position. Nonunion, coded N for this fracture type, means the bone has not united at all. These are opposite clinical states, and they usually call for different surgical interventions.

Distal ulna malunion usually shows up first as lost forearm rotation or a painful wrist. A documented range of motion assessment at the follow-up visit gives the physician the functional evidence to attest to it.

The same malunion logic reaches the carpal bones, where S62.163P marks a closed pisiform fracture healed in malposition.

Subsequent encounter coding: When the R 7th character applies

The ICD-10-CM Official Guidelines for Coding and Reporting (FY2026) define three encounter types for fractures. “Subsequent encounter” does not simply mean any follow-up visit, because the term has a specific technical meaning.

The same convention runs across the injury chapter, which is why S60.931D reads as aftercare rather than a new injury.

• Initial encounter (7th char. A, B, or C): The patient is receiving active treatment for the fracture. This covers the emergency visit, surgery, and any visit where the provider is actively managing the acute injury. A patient can have several initial encounters if different providers deliver active treatment.
• Subsequent encounter (7th char. D through R): Active treatment has finished and the patient is in the healing or recovery phase. This covers cast changes, medication adjustments, follow-up X-rays to monitor healing, and rehabilitation visits.
• Sequela (7th char. S): A late effect or complication that arises after the fracture has healed. The fracture itself is no longer the active problem, and a condition caused by it is.

For S52.692R, the R character is correct when three things are true. Active treatment for the open fracture has ended. The fracture was classified intraoperatively as Gustilo type IIIA, IIIB, or IIIC. The treating physician has documented malunion as the healing complication.

Rehabilitation visits in this phase carry the same diagnosis code as the physician’s follow-up. Good physical therapy software holds that 7th character on the patient record, so nobody re-derives it from scratch at every session.

Code hierarchy and classification for S52.692R

Following the hierarchical chain helps coders confirm they are in the right code family and spot adjacent codes for related fracture types. The CMS ICD-10 codes page publishes the full tabular list with annual updates.

Adjacent codes in the same family include S52.691R for the right ulna and S52.699R for unspecified laterality.

Coding S52.691R when the chart documents the left ulna is among the most common mismatch flags in orthopedic coding audits. Further up the bone, S52.266R applies the same malunion letter to a nondisplaced ulnar shaft fracture.

Approximate synonyms and index terms for S52.692R

Documentation language in operative notes and discharge summaries rarely mirrors ICD-10-CM code descriptions exactly.

Coders need to recognize the clinical phrases that map to this code. The index terms and approximate synonyms below all lead to S52.692R in the Alphabetic Index.

• Other fracture of lower end of left ulna with malunion
• Distal ulna fracture, left, with malunion (subsequent, open type III)
• Malunited fracture of left distal ulna, open type IIIA
• Malunited fracture of left distal ulna, open type IIIB
• Malunited fracture of left distal ulna, open type IIIC
• Fracture lower end left ulna, follow-up, open Gustilo type III, malunion
• Left ulna distal fracture malunion, compound type III
• Malunion, fracture, ulna lower end, left, open fracture type IIIA/IIIB/IIIC

An operative note may say “malunited left distal ulnar fracture following open injury.” That language maps to S52.692R, provided the Gustilo type III classification is also documented. If only one of those two clinical facts appears in the chart, the code is unsupported.

CPT codes commonly used with S52.692R

S52.692R pairs with different procedure codes depending on whether the encounter is surgical or non-surgical. Coders working in sports medicine software or orthopedic EHR environments meet these combinations most often. The AAPC Codify ICD-10-CM lookup provides crosswalk data for verifying medical necessity pairing.

When a subsequent encounter leads to a decision to perform corrective osteotomy, that surgical visit takes an initial encounter character for the corrective procedure. The diagnosis code family stays the same, but the 7th character changes.

Make sure the procedure and evaluation-and-management codes match the scenario documented at that specific visit.

Clinical documentation requirements for S52.692R

Supporting S52.692R on audit takes four specific elements in the clinical record. Miss any one of them and a payer or auditor has grounds to downcode or deny the claim.

• Left laterality confirmed: The chart must specify the left ulna. Right or bilateral documentation does not support S52.692R. If the note says “left distal ulna” and the coder selects S52.691R, the mismatch is an audit risk even when every other element is correct.
• Open fracture type documented: The surgeon must name Gustilo-Anderson type IIIA, IIIB, or IIIC in the operative report. “Open fracture” alone is not enough for the R character. Without a type III designation, R is unsupported and the coder must query the surgeon.
• Subsequent encounter status confirmed: The clinician’s note should show that active fracture treatment is complete and the patient is in the healing phase. Language such as “continued wound care” may imply ongoing active treatment, which would point to a different 7th character.
• Malunion explicitly attested: Malunion cannot be inferred from an X-ray alone. The physician must document it as a diagnosis or clinical finding. Phrases such as “malunited fracture,” “healed in malposition,” or “malunion confirmed on imaging” satisfy this. An imaging report describing malalignment, with no matching physician note, is not enough.

A structured aftercare note that prompts for all four elements removes most of the guesswork. Build it around fracture site and laterality, Gustilo type where the injury is open, current healing status, and any complication.

A SOAP progress note layout handles this well, provided those items sit in discrete fields rather than free-text narrative.

How practice management software supports accurate fracture coding

Fracture coding errors usually begin in the note rather than at the claim stage. When laterality, Gustilo type, and healing status live in free-text narrative, the coder has to read around them and guess. Every guess becomes a query, and every query delays payment.

Practice management software like Pabau lets you turn those four elements into structured fields on the aftercare template.

Clinicians pick the laterality and the Gustilo type at the point of care, so the coder inherits a complete record instead of reconstructing one. Medical records management keeps that history attached to the patient across every subsequent visit.

The same logic applies before the patient arrives. Digital intake and consent forms capture injury history and prior treatment in fields you define. The first note then already carries the detail an open fracture claim needs. Fewer post-encounter queries follow.

On the billing side, Pabau’s claims management tools track what you submitted and where it sits with the payer. Orthopedic and sports medicine teams can spot a pattern of 7th character denials early, rather than discovering it a quarter later in an audit.

Streamline fracture aftercare billing with Pabau

Pabau's claims management tools help orthopedic and sports medicine practices submit accurate ICD-10 codes and track claim status. Fewer denials come back over the wrong 7th character.

Book a demo

Conclusion

The safest habit with this code family is to read the chart before you reach for the letter. Documentation decides the 7th character, and it never works the other way around.

If the operative note names no Gustilo type, R is not yours to use. Query the surgeon and accept the short delay. A queried claim that pays in full beats a fast claim recouped at audit.

Practices that solve this at the template level stop relitigating it on every claim. Building the four documentation elements into the aftercare note is a one-time job with a lasting payoff. Read the practice management software overview, or book a demo to see how Pabau catches documentation problems before they become denials.

Continue your research

Assessing a suspected wrist fracture at the bedside? The scaphoid fracture test walks through each maneuver and what a positive result means for your documentation.

Coding a proximal ulna injury instead? S52.271A covers the initial encounter for a Monteggia fracture of the right ulna.

Need the sequela code for a healed forearm injury? S52.591S shows how the S character works once the fracture is no longer the active problem.

Documenting a wrist dislocation that left lasting effects? S63.004S applies the same sequela convention outside the fracture range.

Checking nerve recovery after a type IIIC injury? The two-point discrimination test gives you normal values and a repeatable technique for follow-up notes.

Frequently asked questions

More questions on S52.692R coding and documentation