ICD-10 code S42.256P: Nondisplaced greater tuberosity fracture with malunion

Key takeaways

ICD-10 code S42.256P covers a nondisplaced fracture of the greater tuberosity of the unspecified humerus at a subsequent encounter with malunion.

The code sits in the humerus branch of S42, so the chain runs S42 to S42.2 to S42.25 to S42.256.

S42.034P is not the humerus version of this code. It sits in the clavicle branch, so check the digits before you submit.

Only A, B, D, G, K, P, and S are valid 7th characters for S42 codes, which means Q and R never belong here.

Imaging that describes the malunited position has to be in the record before the P character goes on a claim.

Practice management software like Pabau keeps the imaging report, the coded diagnosis, and the claim status on one patient record.

ICD-10 code S42.256P: definition and billable status

Most nondisplaced greater tuberosity fractures heal quietly in a sling. When one heals in the wrong position, the shoulder keeps catching and the billing gets harder. ICD-10 code S42.256P covers that visit. The full descriptor is nondisplaced fracture of greater tuberosity of unspecified humerus, subsequent encounter for fracture with malunion.

This code is easy to miss by a single digit, and the digit that slips is usually the third one. S42.0 codes cover the clavicle, so S42.034P describes a nondisplaced fracture of the lateral end of the right clavicle with malunion. Humerus fractures live under S42.2, which is why greater tuberosity malunion is coded to S42.256P.

S42.256P is a valid, billable seven-character code in the FY2026 ICD-10-CM code set, per the Centers for Medicare and Medicaid Services (CMS) ICD-10 code files. It has been reportable since claims moved to ICD-10-CM on October 1, 2015, and it is exempt from present on admission (POA) reporting. Coders in physical therapy and rehabilitation practices meet it most often during fracture aftercare, once imaging confirms the malunion.

Code details at a glance

The table below holds the reference facts you need when ICD-10 code S42.256P goes on a claim.

Coders in sports medicine practices should treat the unspecified laterality as a flag, not a default. If the note or the radiology report names a side, code that side instead. An unspecified code on a shoulder injury invites a request for records, because the side is nearly always documented.

Where S42.256P sits in the ICD-10-CM hierarchy

Every character in this code narrows the diagnosis, so reading the chain from the top is the fastest way to check your work.

• S42: fracture of shoulder and upper arm, inside Chapter 19 (S00-T88).
• S42.2: fracture of upper end of humerus.
• S42.25: fracture of greater tuberosity of humerus.
• S42.256: nondisplaced fracture of greater tuberosity of unspecified humerus.
• S42.256P: the same fracture at a subsequent encounter, healed with malunion.

The fourth character is where the two most confusable branches split. S42.0 is the clavicle, S42.1 is the scapula, and S42.2 is the upper end of the humerus. A code such as S42.034P therefore reports a clavicle injury. Our guide to clavicle fracture malunion coding covers that branch in detail. Submitting a clavicle code for a humerus fracture creates a mismatch between the diagnosis and the imaging in the chart.

You can confirm the full descriptor and the sibling codes in the CDC ICD-10-CM browser tool before submission. The AAPC index for category S42 is useful for the same check.

How the 7th character works for S42 codes

The 7th character carries the encounter logic for the whole visit, and it is one of the most audited details in fracture coding. Category S42 uses seven of them, listed below. Nothing else is valid on a shoulder or upper arm fracture code.

Characters Q and R are a common false friend here. They belong to the Gustilo open fracture extensions. Those appear only on long bone shaft codes, such as the femur (S72), the tibia and fibula (S82), and the forearm shaft (S52). No S42 code takes them. If your encoder offers Q or R on a greater tuberosity fracture, you are looking at the wrong code family.

Malunion, nonunion, and delayed healing

Malunion means the fragments joined in an anatomically wrong position. Nonunion, character K, means they never joined. Delayed healing, character G, means union is late but still happening. For the greater tuberosity, malunion usually means the fragment has healed superiorly or posteriorly relative to the humeral head. That position can impinge the rotator cuff and cap shoulder abduction.

Apply the P character only when imaging, usually an X-ray or MRI, describes that malunited position. Clinical suspicion is not enough. A note that says “fracture healing” without describing the alignment will not hold up on audit, and payers may deny or downcode the visit.

What a nondisplaced greater tuberosity fracture is

The greater tuberosity is the bony prominence on the outer surface of the proximal humerus, just below the humeral head. Three rotator cuff muscles attach there: the supraspinatus, the infraspinatus, and the teres minor. That anatomy is why these fractures so often come with cuff involvement, as the American Academy of Orthopaedic Surgeons (AAOS) describes. Patients usually arrive after a fall onto an outstretched hand, a direct blow to the shoulder, or an anterior shoulder dislocation.

• Nondisplaced fractures: the fragment stays in position or shifts only slightly. Most orthopedic literature treats roughly 5 mm as the point where displacement becomes surgically interesting. Sling immobilization is often enough.
• Displaced fractures: the fragment has migrated further, usually superiorly, and repair is considered more often. Code these to S42.253 for an unspecified humerus, not to S42.256.
• Lesser tuberosity fractures: a different subcategory entirely, S42.26, even though the mechanism can look similar in the note.

Practices at chiropractic and musculoskeletal practices that co-manage shoulder aftercare with an orthopedic surgeon carry a specific risk. The encounter character has to be re-checked at every visit, not set once at the first appointment and left alone.

Sibling and related codes for S42.256P

The codes below are the ones you switch between as a greater tuberosity fracture moves through treatment. The last row is the clavicle code that gets picked by mistake.

Coders who already work with other Chapter 19 injury codes will recognize the pattern. The encounter characters behave consistently across fracture categories, so the learning curve is mostly about knowing which characters each category allows.

Documentation requirements for S42.256P

The ICD-10-CM Official Guidelines for Coding and Reporting, Section I.C.19, are direct about this. The 7th character reflects the healing status at the current visit, not the status recorded at the first one. A fracture coded D for routine healing in week four becomes P once imaging shows malunion in week ten.

• Radiology report: an X-ray or MRI report that describes the malunited position of the tuberosity fragment. This is the primary support for the claim.
• Provider note: an assessment that references the imaging findings and the functional effect, such as impingement or restricted abduction.
• Laterality: the side, wherever the record supports it, so you can code S42.254P or S42.255P instead of the unspecified version.
• Diagnosis wording: the word malunion, or a plain description of healing in an abnormal position. Vague phrasing will not support the P character.
• Plan update: what changes now, whether that is therapy, a surgical referral, or watchful waiting. This explains why the code changed.

Workers’ compensation claims need one more layer. The documentation has to tie the malunion back to the original occupational injury, and state requirements vary, so check the payer’s rules before you submit. Practice management software like Pabau helps here. Its digital intake and clinical forms capture the injury mechanism, imaging findings, and range of motion at every visit. That builds the audit trail as you go, instead of after the denial.

CPT codes commonly paired with S42.256P

Diagnosis and procedure codes have to be clinically plausible together, because payers cross-check the pairing in their claim edits. The codes below are the ones that show up around a greater tuberosity fracture, in the US CPT system. Always confirm payer coverage for a pairing before you submit it.

Codes 23620 through 23630 describe treatment of the acute fracture. They normally sit alongside the initial encounter character, not the malunion one. By the time S42.256P applies, the bone has already united. Procedures at that stage are more likely to be therapy, monitoring imaging, or revision surgery.

If a surgeon does operate to correct the malunion, code the procedure from the operative report rather than from a crosswalk. Malunion correction varies widely, from cuff repair to bone work, and the report is the only reliable source. UK practices bill the equivalent procedures under OPCS codes, while the diagnosis code stays the same.

Reimbursement and payer considerations

Coverage at the malunion stage is where these claims get interesting, because the diagnosis alone does not settle whether an intervention is payable.

• Medicare and Medicaid: coverage follows the local coverage determinations issued by your Medicare Administrative Contractor, so check the LCD for your jurisdiction rather than assuming.
• Pre-authorization: surgical correction of a malunion commonly needs authorization first, and S42.256P is often a required field on that request.
• Commercial payers: thresholds differ on when a malunion is significant enough to fund more than therapy. Document functional loss objectively with range-of-motion measurements.
• Workers’ compensation: expect scrutiny of the link between the malunion and the original incident. Blanket coverage assumptions are a frequent audit failure.

The HIPAA compliance requirements for medical offices apply to all of this documentation and to the electronic transmission of the claim. Some states add their own rehabilitation rules on top of that. Our guide to physical therapy practice requirements in Arizona shows how the layering works.

Common coding errors to avoid

• Reaching for S42.034P: that code reports a clavicle fracture. For the greater tuberosity of the humerus, the base code is S42.256.
• Using P without imaging: the P character needs a radiology report that describes the malalignment, not a clinical impression.
• Leaving the code at D: once malunion is confirmed, later visits move to P. Repeating the routine healing character understates the diagnosis.
• Choosing unspecified laterality: if the note says right or left, code S42.254P or S42.255P instead of S42.256P.
• Trying Q or R: those Gustilo characters belong to long bone shaft codes, so they are never valid on S42.

How Pabau keeps fracture follow-up claims clean

Fracture aftercare is one of the more demanding billing patterns in orthopedic and physical therapy work. The same patient returns five or six times, and the diagnosis character changes partway through. The evidence for that change sits in a radiology report someone has to dig out. Most denials here are administrative, not clinical.

Practice management software like Pabau keeps that evidence and the claim in the same place. Imaging results, treatment notes, and consent forms attach to the patient record. The note supporting a malunion code is one click from the visit it belongs to. Your coder is not hunting through email for the X-ray report.

On the billing side, Pabau’s claims management shows the status of every claim, from pending and submitted through to processing, paid, or error. For practices billing private insurers, it validates insurer-specific fields such as membership and authorization numbers through its Healthcode integration. Choosing the 7th character stays a coder’s judgment call, but nothing sits in limbo while you wait to find out a claim failed.

Keep fracture aftercare claims moving

Pabau keeps imaging reports, treatment notes, and claim status on one patient record. Multi-visit fracture billing stops depending on who remembers which follow-up needs a new code.

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Conclusion

S42.256P is a narrow code, and that is the point of it. It says the greater tuberosity fracture united in the wrong position, at a follow-up visit, on a shoulder the record did not name. Get the branch right first, since S42.2 is the humerus and S42.0 is the clavicle. Then let the imaging decide the 7th character.

The practical win is smaller than it sounds and worth more than it looks. One coding checkpoint at the six-week visit, plus laterality in the note, removes most of the denial risk on this code. Book a demo to see how Pabau keeps fracture documentation and claim status together for orthopedic and physical therapy practices.

Continue your research

Coding a clavicle malunion instead? ICD-10 code S42.012P for clavicle fracture with malunion walks through the S42.0 branch that S42.256P is most often confused with.

Need guidance on physical therapy compliance? Mandatory compliance requirements for physiotherapy clinics covers the documentation standards behind multi-visit episodes of care.

Looking for orthopedic practice management software? Pabau’s physical therapy EMR handles charting, scheduling, and claims for practices running fracture aftercare.

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