ICD code S59.032G – Salter-Harris III fracture of left lower ulna, delayed healing

Key takeaways

S59.032G covers a Salter-Harris Type III physeal fracture of the lower left ulna, coded at a follow-up visit where delayed healing is documented.

The seventh character G means a subsequent encounter with delayed healing, which sits between D (routine healing) and K (nonunion).

The physician’s note decides between D, G and K, so query the physician whenever the healing language is unclear.

Missing laterality, A reused on a follow-up visit, and G assigned before imaging supports delayed healing are common denial triggers for this code.

Practice management software like Pabau keeps laterality, encounter type and healing notes next to the claim, so coders can check them before submission.

ICD-10 Code S59.032G: Definition and full descriptor

ICD-10 Code S59.032G is the billable ICD-10-CM code for a Salter-Harris Type III physeal fracture of the lower left ulna with delayed healing.

You assign it at a subsequent encounter, once the physician documents that the fracture is healing more slowly than expected. The code sits in category S59 (Other and unspecified injuries of elbow and forearm) and is valid for FY2026.

Each character in S59.032G narrows the diagnosis. S59 is the category for other and unspecified elbow and forearm injuries. The fourth character 0 means a physeal fracture of the lower end of the ulna. The fifth character 3 sets Salter-Harris Type III, and the sixth character 2 sets the left arm. The seventh character G marks a subsequent encounter with delayed healing.

Understanding the Salter-Harris Type III classification

A Salter-Harris Type III fracture is a growth plate injury. The fracture line runs through the physis and then through the epiphysis to the joint surface, leaving the metaphysis intact. That joint involvement makes Type III more clinically significant than Types I or II, and it’s why a generic fracture code won’t do.

The five Salter-Harris types describe how the fracture relates to the growth plate. Type I runs through the physis only, and Type II runs through the physis and metaphysis (the most common pattern). Type III runs through the physis and epiphysis into the joint surface. Type IV crosses all three zones, and Type V is a crush injury to the physis.

For billing, the physician’s documentation must state the Salter-Harris type explicitly. Coders can’t infer it from an imaging report without the physician’s interpretive statement.

• Who it affects: Skeletally immature patients, mainly children and adolescents whose growth plates haven’t fused yet.
• Why it matters for coding: The Salter-Harris type sets code specificity, so a generic distal ulna fracture code isn’t an acceptable substitute.
• Articular surface involvement: Extension into the epiphysis raises the risk of growth arrest and joint incongruity, which payers may look for at follow-up visits.
• Documentation requirement: The physician’s note or operative report must say “Salter-Harris Type III.” The phrase “physeal fracture” alone isn’t enough to assign this code.

Anatomy: The lower end of the left ulna

The lower (distal) end of the ulna is the smaller of the two forearm bones at the wrist. In skeletally immature patients, a physeal fracture here affects the distal ulnar growth plate, which typically fuses between ages 16 and 18. S59.032G is left-arm only, and the right-arm code is S59.031G.

If the record doesn’t specify laterality, the code is S59.039G (unspecified arm). Submitting the unspecified code when laterality appears elsewhere in the chart may still trigger a payer query.

“Lower end,” “distal end” and “distal ulna” all describe the same site in S59.032G, so the physician may use any of them. Laterality is the element that can’t vary. Check the operative report, the office visit note and any imaging report for consistent left-arm documentation before you assign the code.

Decoding the seventh character G: Subsequent encounter with delayed healing

The seventh character G means the patient is at a subsequent encounter and the fracture is showing delayed healing. The ICD-10-CM Official Guidelines (Section I.C.19) use subsequent encounters for care after active treatment ends, during the healing or recovery phase. Delayed healing is a clinical judgment by the treating physician. It rests on the absence of expected radiographic union for the fracture type and the patient’s age.

Orthopedic literature often places that window at 6 to 8 weeks for pediatric forearm fractures. Even so, the physician’s documented assessment governs the code, not a fixed calendar threshold. The AAPC ICD-10-CM code reference defines the encounter characters across fracture categories.

G needs the physician to note slow or insufficient healing progress in the record. It doesn’t need a formal “delayed union” diagnosis. K (nonunion) is a stronger conclusion, and it requires the physician to document that the fracture has failed to unite. Assigning K before that conclusion appears in the chart is a coding error, and the same logic holds across injury-chapter fracture codes.

S59.032 code family: All seventh-character variants

Every seventh-character option for S59.032 covers the same injury, a Salter-Harris Type III fracture of the lower left ulna. Each one adds a different encounter or outcome qualifier. The table below maps each variant to its clinical scenario.

Right-arm equivalents use S59.031 with the same seventh characters, and unspecified laterality uses S59.039. G is the variant most easily confused with its neighbors. Coders reuse A on follow-up visits, or jump to K before the physician documents nonunion. The decision flow below shows how the physician’s documentation picks the character at each visit.

S59.032G vs. similar codes: Choosing the right code

Four comparisons come up again and again with S59.032G. Each one turns on a single documentation element that changes the correct code.

Documentation requirements for S59.032G

Every element of the S59.032G descriptor must appear in the medical record before you assign the code. If any area below is undocumented, expect a payer denial or a query from your clinical documentation integrity (CDI) team.

• Salter-Harris Type III: The physician’s note or operative report must state the Salter-Harris type. An imaging report alone isn’t enough unless the treating provider signs and dates it as their own clinical determination.
• Lower end of ulna: Document the site as the distal (lower) end of the ulna. “Forearm” or “wrist” alone isn’t specific enough. Acceptable synonyms include “distal ulna,” “lower ulna” and “lower end of ulna.”
• Left arm laterality: It must appear in the physician’s examination or assessment. The radiologist’s report supports it, but the treating provider’s note should confirm it.
• Subsequent encounter: The encounter must come after active treatment. A covering provider or a new facility doesn’t change this. The character reflects the fracture’s healing stage, not the visit count at that practice.
• Delayed healing: The physician must document clinical or radiographic evidence of slower-than-expected healing. Acceptable language includes “healing slower than expected,” “insufficient callus formation,” “delayed union” or “minimal radiographic bridging at [time point].”

What payers require before accepting S59.032G

Payer requirements for S59.032G vary by Medicare Administrative Contractor (MAC), state Medicaid plan and commercial plan. The points below are general expectations. Always check the payer’s Local Coverage Determination (LCD) or coverage policy before billing.

• Imaging documentation: Most payers expect a radiograph or MRI interpretation that supports the delayed-healing assessment. The imaging report should be dated on or before the claim’s date of service.
• Timeframe alignment: S59.032G claims for visits in the first two to three weeks after the initial encounter often get flagged. Delayed healing is a conclusion reached over time, so the date of service should fit a follow-up timeline.
• Subsequent care vs. aftercare codes: Report follow-up fracture care with the fracture code and its seventh character. That covers cast changes, healing x-rays and medication adjustments. The official guidelines rule out aftercare Z codes for injuries, because the seventh character already identifies subsequent care.
• Prior authorization: Some commercial payers require prior authorization for procedures that accompany S59.032G, such as casting changes or follow-up imaging. Authorization attaches to the CPT code, but payers still review the diagnosis for medical necessity.

Common S59.032G claim denial reasons and how to avoid them

Most S59.032G denials come from correctable documentation and coding errors rather than a lack of medical necessity. Read the denial reason on the explanation of benefits (EOB) against the list of medical billing denial codes. That’s the fastest route to a clean corrected claim. The patterns below are the ones to check first.

Track denials by code. If S59.032G claims keep coming back for the same reason, fix the documentation upstream instead of working appeals downstream.

CPT codes commonly paired with S59.032G

CPT code selection depends on the procedure performed at the encounter, not on the diagnosis code. The table below lists CPT codes often billed alongside S59.032G in orthopedic and pediatric practices. All pairings are illustrative, so verify them against the AMA CPT code set and the services rendered before billing.

CPT 25600 describes distal radius fracture care that can include the ulnar styloid. Confirm the encounter notes support the procedure billed, and query the physician when in doubt.

ICD-9-CM crosswalk for S59.032G

ICD-9-CM lacked the specificity of ICD-10-CM for physeal fractures. The legacy codes below are approximate matches only, because the General Equivalence Mappings (GEMs) don’t guarantee clinical equivalence. Use them for historical record reconciliation or research on pre-2015 claims data.

ICD-9-CM didn’t capture Salter-Harris class, laterality or delayed healing at the level ICD-10-CM provides. Historical analysis on ICD-9 data will undercount physeal fracture specificity. Label crosswalk content accordingly in research protocols and in payer appeals that cite legacy data.

Includes, excludes, and instructional notes for S59.032G

The parent categories of S59.032G carry instructional notes that govern its use, so apply them before you finalize a claim. The notes below come from the CDC/NCHS ICD-10-CM web tool and the official tabular list.

• Excludes2 (S59 category): Other and unspecified injuries of wrist and hand (S69.-). An Excludes2 note means the excluded condition isn’t part of S59, but both codes can be reported together when the patient has both.
• No Excludes1 note on S59.0: The physeal fracture subcategory carries no Excludes1 note of its own. Code each documented fracture site separately, following the physician’s note.
• Note (Chapter 19, injury chapter): Use secondary codes from Chapter 20 (external causes of morbidity) to identify the cause of injury when documentation supports it. They supplement the principal code and never replace it.

How Pabau supports documentation and billing for S59.032G

Orthopedic and pediatric practices billing S59.032G hit the same problem at follow-up visits. The note often holds the right information, but laterality and healing-progress language sit deep in the exam narrative. The billing team has to dig for them before every claim.

Practice management software like Pabau connects the clinical note to the billing queue. Its claims management software lets coders see the treating physician’s notes, imaging references and encounter history in one place before a claim goes out.

For US practices, Pabau sends electronic claims to thousands of US payers through the Claim.MD clearinghouse and checks patient eligibility in real time. Electronic remittance advice (ERA) comes back into Pabau against each claim. When an S59.032G claim is denied, you can see whether laterality, the seventh character or missing documentation caused it.

Fewer claims come back, and the ones that do take less time to correct. Book a demo to see how Pabau handles fracture documentation and claim submission from start to finish.

Submit cleaner fracture claims the first time

Pabau keeps laterality, encounter type and healing notes beside the claim, so coders can confirm S59.032G before it reaches the payer.

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Conclusion

S59.032G is easy to get right when the chart is built for it, and costly to get wrong when it isn’t. At every follow-up, the deciding question is what the physician wrote about healing.

Treat D as the default for follow-up visits, and move to G only when the note says healing is slower than expected. If the note is ambiguous, a physician query takes minutes, while a denied claim can take weeks to resolve.

The trade-off is a little more discipline at the point of care, in exchange for claims that clear the first time. Book a demo to see how Pabau puts the healing notes and the claim side by side for your coders.

Continue your research

Need to trace denials back to the documentation behind them? Denial management in healthcare walks through how to analyze EOB patterns and fix recurring coding errors at the source.

Submitting ICD-10 claims through a clearinghouse? Electronic remittance advice explained covers how ERA files map payer decisions back to specific claim lines.

Looking for the billing compliance framework behind fracture coding? Medical billing compliance guidance covers the documentation standards that apply across ICD-10-CM injury codes.

Want the whole path from encounter to payment? What is revenue cycle management explains each stage a fracture claim passes through before it is paid.

New to the billing side of the practice? What is medical billing covers how clinical documentation turns into a claim a payer will accept.

Frequently asked questions about ICD-10 Code S59.032G