ICD-10 Code S62.172K: Displaced fracture of trapezium, left wrist, nonunion

Key takeaways

ICD-10 Code S62.172K covers a displaced trapezium fracture in the left wrist, coded at a follow-up visit after the bone failed to unite.

The 7th character K separates nonunion from routine healing (D), delayed healing (G), and malunion (P). Pick the wrong one and the claim gets denied.

S62.172K needs documented nonunion confirmed on imaging, explicit left-side laterality, displacement status, and the encounter type.

Pabau’s ICD-10-CM catalog sits inside the patient record, so coders assign S62.172K without opening a separate lookup tool.

ICD-10 Code S62.172K is the billable code for a displaced fracture of the trapezium in the left wrist. It applies at a subsequent encounter, once the fracture has failed to unite. The 7th character K is what records that failure.

Each of the four subsequent-encounter characters (D, G, K, and P) reports a different healing outcome. The choice therefore changes how the payer reads the claim.

This reference covers the clinical definition, every 7th character variant, the full S62.172 family, and the documentation a payer expects. It also walks the official guidelines for fracture aftercare.

ICD-10 Code S62.172K: Definition and clinical description

ICD-10 Code S62.172K is a billable, specific ICD-10-CM diagnosis code. Its full official description reads: Displaced fracture of trapezium [larger multangular], left wrist, subsequent encounter for fracture with nonunion. Every word in it carries billing weight.

• Displaced: the fracture fragments have shifted out of anatomical alignment
• Trapezium: the specific carpal bone at the base of the thumb
• Left wrist: the laterality a payer checks against the record
• Subsequent encounter: the visit falls after the acute treatment phase
• Nonunion: the bone has not healed as expected

The 2026 edition of ICD-10-CM S62.172K became effective on October 1, 2025, per the CMS ICD-10-CM annual update schedule. The code falls within the S60-S69 block, which covers injuries to the wrist and hand. Its category is S62, fractures of wrist and hand bones.

The parent code S62.172 is not billable on its own, because a 7th character must be appended. S62.172K is the billable form that reports follow-up care during confirmed nonunion. Orthopedic teams and physical therapy practices managing wrist fracture aftercare meet this code once imaging confirms the fracture has not bridged.

Code details at a glance

The table below summarizes the key attributes of S62.172K for a quick lookup during coding or documentation review.

For the official code definition and annual tabular updates, consult the CDC/NCHS ICD-10-CM web tool, which mirrors the authoritative CMS code files each fiscal year.

Anatomy: The trapezium bone and why fractures happen

The trapezium, also called the larger multangular, sits at the base of the thumb in the distal row of carpal bones. It articulates with the first metacarpal, the trapezoid, the scaphoid, and the second metacarpal. That first joint is the carpometacarpal joint of the thumb.

The carpometacarpal joint is a high-motion saddle joint. Forces travelling through the thumb during gripping, falling, or impact therefore concentrate directly on the trapezium.

Trapezium fractures most commonly follow axial loading along the thumb, direct blunt impact, or avulsion forces at ligament attachments. The classic mechanism is a fall on an outstretched hand with the thumb abducted. Displaced fractures, the group S62.172K sits in, occur when the fragments separate from their anatomical position.

• Location: Distal carpal row, radial side, articulating with the first metacarpal
• Also called: Larger multangular, which is why ICD-10-CM carries both names in brackets
• Common fracture mechanism: Axial load through the thumb, hyperextension, or direct impact
• Why displacement matters: Separated fragments disrupt joint congruity at the carpometacarpal joint, raising the risk of nonunion and post-traumatic arthritis
• Laterality rule: S62.172K specifies the left wrist, the right wrist uses S62.171K, and unspecified laterality uses S62.179K

Displaced vs. nondisplaced fracture: What the code tells you

Displacement status is a clinical determination made by the treating provider, not an assumption a coder can make from the claim alone. ICD-10-CM separates displaced and nondisplaced trapezium fractures into distinct code families, because the two carry different treatment pathways, healing timelines, and complication risks.

The medical record must explicitly state “displaced” to support S62.172K. Where documentation says only “fracture”, the ICD-10-CM guidelines default to displaced, but a coder should query the provider rather than assume. Using the nondisplaced family instead, S62.182K, misreports the clinical picture and can affect payment for the associated surgical or casting work.

Understanding the 7th character in S62.172 codes

The 7th character turns S62.172 from a non-billable stub into a fully specific, billable code. It encodes the encounter type and the fracture’s healing status at the time of the visit. Getting this character wrong is the most common coding error on fracture follow-up claims.

Each character is mutually exclusive for a given encounter, so a visit cannot be both routine healing (D) and nonunion (K). The provider’s assessment at that follow-up visit decides which character applies. That assessment has to be in the record before the claim is coded.

The AAPC’s ICD-10-CM code lookup cross-references 7th character extensions across the fracture families, which helps when you are checking a neighboring code.

Why K? Understanding fracture nonunion

Nonunion means the fracture has failed to achieve bony union within the expected healing window. For most carpal bones that window runs 6-12 weeks for nondisplaced fractures, and longer for displaced ones. Imaging taken after it that still shows a fracture gap, absent callus bridging, or sclerotic margins supports a diagnosis of nonunion.

Nonunion is not the same as delayed healing, which takes the 7th character G instead. With delayed healing the bone is still progressing toward union, only more slowly than typical. Nonunion means that progression has stopped, and it is that distinction auditors look for when they review S62.172K billing.

• Risk factors for trapezium nonunion: Fragment displacement, inadequate immobilization, avascular necrosis, smoking, poor vascularity at the fracture site, infection, or premature return to activity
• Imaging confirmation needed: X-ray at minimum, with CT for a definitive read on the fracture gap and callus status
• Clinical signs: Persistent pain over the trapezium, tenderness with carpometacarpal joint loading, crepitus, or failed cast treatment
• Treatment implication: Confirmed nonunion usually points to surgery, such as bone grafting or internal fixation, which generates its own CPT codes alongside S62.172K

Where the character and the note disagree, the claim comes back with one of the common denial codes for a diagnosis the payer cannot reconcile. Practices working high volumes of fracture follow-ups therefore track how the 7th character moves across encounters.

Related codes across the S62.17 and S62.18 families

Two decisions produce the code. Displacement and laterality choose the base code, then the 7th character records the encounter and the healing status.

The table below lists every billable variant in the S62.172 family, alongside its immediate siblings in the S62.17 and S62.18 groups.

S62.179K, the unspecified-laterality option, belongs only in the rare case where the record genuinely does not say left or right. Laterality is almost always determinable from a radiology report, a cast record, or an operative note. Defaulting to unspecified when it is determinable invites payer scrutiny on medical necessity review.

When to use S62.172K: Clinical scenarios and documentation requirements

S62.172K applies when three conditions are all true at the encounter. The patient had a displaced trapezium fracture of the left wrist. The visit is a follow-up rather than the acute presentation. The provider has determined, from clinical assessment and imaging, that the fracture has not healed.

The table below maps each clinical finding to the character it supports. Auditors work the same way when they review fracture aftercare claims, starting from what the note says about healing rather than from the code.

Four documentation elements support ICD-10 Code S62.172K. The provider states that the fracture is not healing. Imaging results, read by the radiologist or the provider, confirm nonunion. The record documents left-wrist laterality. The note confirms this is a subsequent encounter rather than the original visit.

Missing any one of those elements creates an audit vulnerability and risks a denial. A clean claim submission starts in the note, not on the claim form. Structuring fracture follow-ups around encounter type, healing status, and laterality is the cheapest control available.

ICD-10-CM coding guidelines for fracture aftercare

The ICD-10-CM Official Guidelines for Coding and Reporting, Section I.C.19, set the rules for fracture coding at initial and subsequent encounters. For a traumatic fracture such as a displaced trapezium fracture, the guidelines require the traumatic fracture code for every encounter, including aftercare. Pathologic fractures work differently, and may take an aftercare code from the M84 series.

• Aftercare Z codes do not apply to traumatic fracture follow-up, so use the S62.172 family with the appropriate 7th character across the whole care episode
• Initial encounter (A) covers any visit during active treatment, including surgery or casting. More than one provider can bill A on the same fracture
• Subsequent encounter characters (D, G, K, P) apply once active treatment is complete and the patient is in the healing phase, however many visits follow
• Sequela (S) applies to late complications of a fully healed fracture, such as post-traumatic arthritis or chronic pain from the original injury
• Laterality must match the record, because the guidelines require the specific laterality character whenever it is documented

The ResDAC guide to ICD codes in Medicare files explains how ICD-10-CM codes flow through Medicare claims data. That matters for orthopedic practices carrying significant Medicare volume.

How Pabau supports accurate fracture coding

Submitting ICD-10 Code S62.172K cleanly needs three things to line up. The clinician documents the healing status, the coder assigns the matching 7th character, and the claim reaches the payer without technical errors. A breakdown at any stage costs more to appeal than it would have cost to prevent.

Practice management software like Pabau keeps those three steps on one record. Its ICD-10-CM catalog is built into the platform, so a coder searches and assigns S62.172K inside the patient chart. There is no switch to an external lookup tool and no retyping of the code.

Pabau’s claims tools for coders route claims electronically through Claim.MD, our US clearinghouse partner, to thousands of payers. Its clean-claim checks look for missing required fields before the claim leaves the practice, such as membership numbers and authorization codes.

When a S62.172K claim is denied, the electronic remittance advice returns through the same integration with CARC denial codes. Billing staff can see whether the problem was missing documentation, the wrong 7th character, or payer-specific nonunion criteria, then resubmit from the same screen. Orthopedic and musculoskeletal practices can book a demo to watch a nonunion claim move from note to payment.

See how Pabau supports ICD-10-CM coding workflows

Pabau helps orthopedic and musculoskeletal practices assign codes like S62.172K inside the patient record, submit claims through Claim.MD, and work denials from the same screen. Book a demo to see the billing workflow end to end.

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Conclusion

Fracture nonunion billing sits where clinical precision meets coding accuracy. The K in S62.172K tells the payer that the bone stopped healing, that care has moved past routine aftercare, and that imaging confirms it.

Coding D when K applies, or billing K without documented imaging, turns a legitimate claim into a preventable denial. The fix sits upstream of the claim form. Query the note before the encounter is coded.

Build the healing-status question into every fracture follow-up and the 7th character takes care of itself. Book a demo to see how Pabau keeps the note, the code, and the claim on one record.

Continue your research

Coding the neighboring carpal bone? ICD-10 code S62.185K covers a nondisplaced trapezoid fracture of the left wrist with nonunion.

Same wrist, different bone? ICD-10 code S62.032S shows how a displaced scaphoid fracture is reported once the case reaches sequela.

Need the malunion equivalent? ICD-10 code S62.163P walks the P character, for a fracture that healed in the wrong position.

Nonunion in a finger rather than the wrist? ICD-10 code S62.606K applies the same K character to a right little finger fracture.

Working denied fracture claims? Denial management in healthcare sets out how to triage, appeal, and track denials before they age out.

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