ICD-10 code S49.029P: Salter-Harris II malunion, unspecified arm

Key takeaways

ICD-10 code S49.029P describes a Salter-Harris Type II physeal fracture of the upper end of the humerus, unspecified arm, subsequent encounter for fracture with malunion.

The sixth character 9 means the record did not state a side. Use S49.021P for a documented right arm and S49.022P for a documented left arm.

S49.029P is a billable, specific ICD-10-CM code valid in the 2026 edition (effective October 1, 2025).

The 7th character P signals a subsequent encounter where the fracture healed in an abnormal position. Distinguish it carefully from K, which indicates failed healing.

Practice management software like Pabau can require laterality, encounter type, and fracture classification on every follow-up note.

ICD-10 code S49.029P reports a Salter-Harris Type II physeal fracture of the upper end of the humerus at a subsequent encounter. The fracture has healed in a malunited position. The sixth character carries laterality, and the 9 here stands for an arm the documentation never named.

That makes S49.029P the unspecified-arm option in its subcategory. It applies only when no side appears anywhere in the record. When the note documents the left arm, S49.022P is the code the claim needs. When it documents the right arm, S49.021P is correct.

S49.029P is billable in the 2026 ICD-10-CM edition, effective October 1, 2025. The P is what makes it a subsequent-encounter code, so it never fits the visit where treatment begins. Everything below reflects that edition, from the 7th character table to the documentation an auditor expects.

ICD-10 code S49.029P: Overview and full description

Full description: Salter-Harris Type II physeal fracture of upper end of humerus, unspecified arm, subsequent encounter for fracture with malunion.

S49.029P is confirmed billable in the CDC/NCHS ICD-10-CM official tool for FY2026. It can stand alone on a claim form for a subsequent-encounter visit.

The visit must involve a previously diagnosed Salter-Harris Type II proximal humerus fracture that has healed in a malunited position, with no side recorded. For physical therapy practices managing long-term fracture aftercare, the encounter type coded at each visit determines whether the claim reflects the patient’s current clinical status.

What does S49.029P mean? Breaking down each code segment

Every character in S49.029P carries a specific meaning. Misreading any single segment leads to the wrong code selection.

Laterality note: The sixth character in the S49.02x subcategory has three values. A 1 means the right arm, a 2 means the left arm, and a 9 means the arm was not specified. S49.029P therefore covers a Type II malunion where the chart names no side at all.

Reach for S49.029P only after you have read the record and found no laterality in it. If the provider documented left or right, the specific sibling code applies, and a provider query beats defaulting to unspecified. Cross-reference the tabular list in the CMS ICD-10-CM code files to confirm current subcategory definitions.

Clinical description: Salter-Harris Type II physeal fracture of the upper humerus

The physis, or growth plate, is the cartilaginous zone at the end of long bones where longitudinal growth occurs in skeletally immature patients. Because the physis is structurally weaker than the surrounding cortical bone in children, it fractures under forces that would cause ligamentous injuries in adults.

The Salter-Harris classification system grades physeal fractures by the fracture line’s relationship to the growth plate:

Type II at the proximal humerus is among the most common physeal fractures in children. It typically follows a fall on an outstretched arm or direct shoulder trauma. The fracture line passes through the physis and exits through the metaphysis. That leaves a triangular bony fragment on the metaphyseal side, known as the Thurston Holland sign on imaging.

Under the WHO ICD-10 classification framework, physeal fractures sit among growth plate injuries and need precise sub-typing. The same typing drives the code at every physeal site, from the proximal humerus to S59.219A at the upper radius.

For sports medicine practices treating adolescent athletes, proximal humerus physeal fractures are a recurring presentation. Most Type II injuries heal with conservative management. Subsequent-encounter codes like S49.029P therefore appear across several follow-up visits during the healing phase.

The 7th character P: Subsequent encounter for fracture with malunion

The 7th character is the most consequential coding decision for S49.029P. It encodes both the encounter type (initial, subsequent, or sequela) and the healing status at the time of the visit. Using the wrong character is one of the most common reasons fracture aftercare claims are denied or audited.

7th character extensions for S49.029: Complete reference table

The AAPC ICD-10-CM reference and the ICD-10-CM Official Guidelines for Coding and Reporting agree on one rule here. The 7th character must reflect the patient’s healing status at the time of the encounter, not the status at fracture diagnosis.

A fracture recorded as routine on earlier visits may move to G, K, or P later. The change is coded once imaging confirms delayed healing, nonunion, or malunion.

Malunion vs. nonunion: coding the correct 7th character

Coders frequently confuse K and P. The difference comes down to whether the bone healed at all:

• Malunion (P): The fracture has healed, but in a suboptimal or angulated position. Bone continuity is re-established, and the problem is the alignment. Imaging shows bony bridging with angular or rotational deformity.
• Nonunion (K): The fracture has failed to heal. No bony bridging is present. The fracture gap persists despite adequate time and immobilization.
• Delayed healing (G): Healing is in progress but slower than expected for the patient’s age and injury type. The fracture line is still visible, but early callus formation is evident.

Use P when the orthopedic or treating provider documents ‘malunion,’ ‘healed in poor alignment,’ ‘angular deformity at fracture site,’ or equivalent language.

Without that explicit documentation, K or G may be more defensible, depending on the imaging findings. Nearby fracture codes follow the same logic, so a documented nonunion at the medial epicondyle takes S42.442K.

Practices using structured clinical records can configure note templates to prompt for healing status at each fracture follow-up. That makes the 7th character selection reproducible across encounters.

Related codes in the S49.0 physeal fracture family

S49.029P sits within a tightly organized code family. Knowing the sibling codes prevents laterality miscoding and helps coders navigate adjacent Salter-Harris types at the same anatomical site.

The parent block S49.0 covers all physeal fractures of the upper end of the humerus. S42 covers traumatic fractures of the shoulder and upper arm, where malunion codes such as S42.211P and S42.242P take the same 7th character. Reaching into S42 for a physeal injury is one of the more common miscodes at this site.

Documentation requirements for S49.029P

Every element of S49.029P must be explicitly supported in the medical record. Coders cannot infer healing status or fracture classification from ambiguous notes. The following checklist reflects what payers and auditors expect to find when this code appears on a claim.

• Fracture type documented: The chart note must state ‘Salter-Harris Type II’ or describe a physeal fracture with metaphyseal extension. A generic ‘proximal humerus fracture’ is insufficient.
• Anatomical site confirmed: ‘Upper end of humerus’ or ‘proximal humerus’ must appear. ‘Shoulder fracture’ alone does not meet specificity.
• No laterality in the record: S49.029P is supportable only when the note names no side. If the chart documents left or right, code S49.022P or S49.021P instead.
• Provider query recorded: Auditors expect evidence that you asked about the side before coding unspecified. Keep the query and the response in the chart.
• Encounter type confirmed: The visit must be a follow-up or aftercare encounter, not the initial fracture presentation. An initial-encounter note behind a subsequent-encounter code creates an audit vulnerability.
• Malunion documented: The treating provider must have documented ‘malunion,’ ‘healed in angulated position,’ ‘persistent deformity,’ or imaging findings described as malunion. Radiology reports confirming angular healing satisfy this requirement when linked to the clinical note.
• Imaging correlation: X-ray or MRI findings should align with the malunion description. The date of imaging relative to the date of service matters for audit purposes.

Practices that use structured digital intake and clinical forms can embed required fields for fracture classification, laterality, and healing status. Those fields sit in the follow-up visit workflow, so the coder is not mining free text for them.

Unspecified laterality draws the same scrutiny elsewhere in the chapter, including at codes like S42.436B. Auditors read an unspecified digit as a documentation problem, so the query trail in the chart matters.

Common coding errors and how to avoid them

Six mistakes come up again and again in physeal fracture coding. Each one is visible in the chart before the claim goes out.

• Reading the 9 as a left-arm digit. The 9 means unspecified, so a documented left-arm fracture belongs on S49.022P.
• Defaulting to unspecified to save time. Payers may deny an unspecified code when the imaging report names a side. Query the provider first.
• Carrying the initial-encounter character forward. Aftercare visits take D, G, K, or P, never A.
• Coding malunion from symptoms alone. Persistent pain does not support P. The note or radiology report must describe abnormal healing.
• Reusing the previous visit’s 7th character. Healing status is re-assessed at every encounter, so the character can change mid-episode.
• Choosing S42 over S49.0. S42 covers traumatic shoulder and upper arm fractures, while physeal fractures of the upper humerus sit in S49.0.

Pediatric considerations and billing context

Physeal fractures, by definition, occur at growth plates that are still open. That makes S49.029P a predominantly pediatric diagnosis. The proximal humerus physeal plate typically closes between ages 16 and 20, according to orthopedic clinical literature. Once skeletal maturity is reached, the physis ossifies and physeal fractures are no longer possible at that site.

This has two practical coding implications:

• Age plausibility: If S49.029P appears on a claim for a patient over age 25, expect payer scrutiny. Documentation should confirm open growth plates or explain the unusual circumstance.
• Pediatric billing nuances: For patients covered under pediatric Medicaid or CHIP, fracture aftercare coding may follow state-specific sequencing rules. Review the applicable payer guidelines before submission.

S49.029P can stand alone on a claim, or it can sit alongside procedure codes for aftercare, therapy, and surgical correction. A hardware adjustment during that correction, for example, is billed with 20697.

Practices using integrated claims management software can attach the right CPT or HCPCS codes for each visit type. Always verify payer-specific medical necessity requirements, since coverage for malunion treatment may require prior authorization.

For practices managing pediatric fracture aftercare, consistent encounter-type coding across the care episode builds a defensible claim history. An encounter sequence that runs from S49.029A to S49.029D and then to S49.029P tells a clinically coherent story. Payers and auditors can follow that progression from initial visit to routine healing to confirmed malunion.

How Pabau keeps laterality and encounter type in the record

In many orthopedic and physical therapy practices, the side and the healing status live in free-text notes. A coder reading that entry weeks later cannot tell whether laterality was assessed and omitted, or never assessed at all. Unspecified codes then get used as a fallback rather than a finding.

Practice management software like Pabau puts those details in fixed fields instead. Structured clinical forms can require the side, the Salter-Harris type, and the healing status before a follow-up note is signed. Every encounter then carries the data the 7th character depends on.

Pabau’s claims management tools carry that structured data through to the claim itself. Coders can see at a glance whether a side was documented, so S49.021P, S49.022P, and S49.029P stop being interchangeable. Fewer unsupported codes reach the payer, so fewer follow-up visits turn into appeals.

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Pabau's structured clinical forms and claims management tools help practices document fracture classification, laterality, and healing status at every follow-up visit. The right 7th character stays supportable on every claim.

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Conclusion

Getting ICD-10 code S49.029P right comes down to three checks. The note must classify the fracture, the record must show that no side was documented, and the provider must state malunion. When a side does appear in the chart, S49.022P or S49.021P is the code the claim needs.

For practices handling orthopedic fracture aftercare, the choice between D, G, K, and P often decides whether a claim passes on first submission. Structured documentation workflows that capture Salter-Harris type, side, and healing status at every visit remove the ambiguity behind those denials.

Pabau’s compliance management tools and structured note templates support exactly that workflow. To see how it works in practice, book a demo with the Pabau team.

Continue your research

Need the procedure side of a malunion repair? 01744 covers the anesthesia code for a nonunion or malunion repair at the elbow.

Coding a buckle fracture that healed crooked? S42.489P applies the same malunion character to a torus fracture of the lower humerus.

Tracking progress across a long aftercare episode? Global Rating of Change gives you a scored way to document how much the patient feels has changed.

Examining a pediatric patient at the follow-up visit? Pediatric physical examination covers what to check and how to document it.

Frequently asked questions

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