ICD-10 Code S92.209K: Fracture of unspecified tarsal bone, nonunion

Key takeaways

S92.209K is a billable ICD-10-CM code for a tarsal bone fracture that has failed to unite. It took effect on October 1, 2025, in the FY2026 edition.

The 7th character K means the fracture has not healed. Use K instead of D when imaging or clinical evidence confirms nonunion.

Laterality is intentionally unspecified in this code. Use S92.201K for the right foot or S92.202K for the left when the note names the side.

Practice management software like Pabau submits the finished claim, checks eligibility in real time, and tracks its status until the remittance posts.

ICD-10 Code S92.209K: Full description and billable status

ICD-10 Code S92.209K is a billable diagnosis code for a fracture of unspecified tarsal bone(s) in an unspecified foot. It applies at a subsequent encounter, once imaging or clinical evaluation confirms the fracture has not united. Coders reach for it when the chart documents nonunion but never names the affected foot.

S92.209K is accepted for reimbursement and electronic claim submission. Once the visit is coded, claims management software can submit the claim, check eligibility in real time, and track its status to remittance. The FY2026 edition of ICD-10-CM took effect on October 1, 2025, per the CMS ICD-10 codes page. The code remains valid for the current fiscal year.

Understanding the 7th character K in fracture codes

The parent code S92.209 is not billable on its own. Every claim built on it needs a 7th character, and that character tells the payer which phase of healing the visit covers. Orthopedic billing teams and practices running a physical therapy EMR assign it on every subsequent encounter.

The 7th character K means the fracture has not healed. There is no bridging callus, no clinical union, and the treating clinician has documented that finding. That differs from a fracture still working through recovery. All seven valid 7th characters for the S92.209 family are below.

Nonunion vs. malunion vs. delayed healing: coding differences

Payers scrutinize these three options closely because each implies a different level of clinical intervention and cost. Misassigning G when K is clinically supported can result in denial of surgical authorization. Misassigning K when D would be correct raises audit risk.

• Nonunion (K): The fracture site shows no evidence of bone bridging after an expected healing window, typically confirmed by X-ray or CT. Clinically, the patient often has persistent pain and instability at the fracture site. This is the correct character when documentation states “nonunion” or “failed healing.”
• Delayed healing (G): The fracture is progressing toward union but more slowly than expected. There is some callus formation or biological activity at the site. The distinction from K is that healing is still occurring, just behind schedule.
• Malunion (P): The fracture has united, but the bones healed in an angulated, shortened, or otherwise abnormal position. The final position is what needs correcting, since union itself has occurred.

The CDC/NCHS ICD-10-CM web tool lets coders verify the full tabular description and inclusion notes before finalizing a claim. The same 7th character logic runs through the long-bone codes, so S82.291J is built exactly the same way.

Code hierarchy: where S92.209K sits in ICD-10-CM

Understanding the parent code chain helps coders navigate the S92 family when building crosswalks or a medical coding cheat sheet for their specialty. S92.209K descends through five levels of specificity from the injury chapter root.

Related and sibling ICD-10 codes

Coders frequently need to choose between sibling codes when laterality is documented or the encounter type changes. The table below shows the most common codes in the S92.209 family alongside the laterality-specific alternatives. When the note names the specific tarsal bone, a more precise code applies, such as S92.145K.

Associated CPT codes for tarsal bone fracture nonunion

Standard code lookup tools stop at the diagnosis. This section lists the procedure codes most commonly paired with S92.209K. For practices running sports medicine software, a verified CPT-to-ICD-10 pairing list cuts coder lookup time and supports medical necessity documentation.

The CPT codes below cover surgical and non-surgical management of tarsal bone fracture nonunion. Verify each pairing against current NCCI edits and payer policy before submission, because coverage and bundling rules vary. Rehabilitation visits billed against this diagnosis may also draw on coaching CPT codes for patient education and self-management training.

ICD-10-CM coding guidelines for fracture subsequent encounters

According to the ICD-10-CM Official Guidelines for Coding and Reporting (Section I.C.19), fracture aftercare does not follow the Z-code approach used for other conditions. When a patient returns for continued fracture treatment, coders use the fracture code with the correct 7th character. A Z-code for aftercare does not replace it, even for nonunion management.

This is one of the most frequently misapplied rules in orthopedic coding. Pediatric foot injuries sit in a separate physeal series, where S99.101D covers the follow-up visit.

• Active treatment vs. aftercare: Use the fracture code (with A, B, or appropriate 7th character) while the patient is receiving active treatment. Subsequent encounter codes (D, G, K, P, S) apply after the provider’s primary care phase is complete.
• Nonunion requires active documentation: The nonunion designation is not assumed. Clinical notes must reflect imaging findings, physical examination evidence, or a direct clinical statement of nonunion.
• Laterality should always be specified when known: S92.209K uses “unspecified foot,” which is acceptable when chart documentation genuinely does not specify the side. Using this code when laterality is clearly documented is considered a coding deficiency by payers and auditors.
• Z codes are not appropriate here: Z47.89 covers encounter for other orthopedic aftercare. It does not replace a fracture code with the correct 7th character. Use S92.209K for an established nonunion visit.

The AAPC Codify ICD-10-CM lookup carries the tabular guidance and coding notes that support 7th character selection.

Documentation requirements for a nonunion claim

A nonunion coding designation without supporting documentation is the fastest route to a claim denial or a post-payment audit. Practices using integrated patient record management can build structured note templates that prompt clinicians to capture all required elements at the point of care. The elements below are what payers and auditors look for when reviewing a claim coded S92.209K.

• Imaging confirmation: X-ray or CT documenting absence of bone bridging or callus formation at the fracture site. The report or reading should use language consistent with nonunion (e.g., “no evidence of union,” “persistent lucency at fracture site”).
• Encounter type documentation: The note must clearly indicate this is a subsequent visit, not the initial fracture treatment. Date of original injury and prior treatment summary support this.
• Laterality notation: If the treating clinician can confirm right or left foot, document it. Use S92.201K or S92.202K accordingly. Defaulting to S92.209K when laterality is known creates audit exposure.
• Clinical findings consistent with nonunion: Persistent pain, instability, or functional limitation that correlates with the imaging finding strengthens the documentation record.
• Payer-specific requirements: Some payers require prior authorization for surgical treatment of fracture nonunion and may need the imaging report attached to the authorization request. Confirm requirements before scheduling procedures billed alongside S92.209K.

For orthopedic and podiatric practices, the Ottawa Ankle Rules calculator supports foot and ankle injury assessment at the initial visit. Clinicians coordinating the rehabilitation that follows can work from a return-to-running protocol to line treatment milestones up with billing.

Synonyms and inclusion terms

ICD-10-CM includes a set of approximate synonyms and inclusion terms used in clinical documentation that map to this code. When a clinician’s note uses any of the following phrases, the coder’s index should lead to S92.209K or its laterality-specific sibling.

• Fracture of tarsal bone, foot, nonunion
• Fracture of cuboid bone, subsequent encounter for nonunion (when specific tarsal bone is not specified in full detail)
• Fracture of cuneiform bone of foot, subsequent encounter for nonunion
• Fracture of navicular bone, subsequent encounter for nonunion
• Tarsal bone fracture not healing
• Failed healing tarsal fracture, subsequent encounter

“Unspecified tarsal bone(s)” in the code title means the documentation never names which tarsal bone broke. Laterality is a separate dimension of specificity, carried by the sixth character.

If the note names a specific tarsal bone, a different code from the S92 family applies. That includes the calcaneus, talus, navicular, cuboid, and the cuneiform bones. Midfoot pain that mimics a cuboid fracture can also come from cuboid subluxation, which the cuboid syndrome test helps identify.

How claims management software handles a nonunion claim

Plenty of practices code the nonunion visit in one system, then re-key the claim into a clearinghouse portal. Eligibility gets checked by phone, and nobody knows the claim’s status until a remittance arrives weeks later.

Practice management software like Pabau keeps that work in one place. Once the visit is coded and invoiced, Pabau submits the claim electronically through Claim.MD in the US. Real-time eligibility checks run before the appointment, so you know what the plan covers.

From there, claim status updates and electronic remittance advice post back against the invoice. Your team can see which nonunion claims are still open without logging into a payer portal. Denials surface in days rather than at month end.

Submit and track fracture claims in one place

Pabau submits your coded claims electronically, runs real-time eligibility checks, and posts remittance advice back against the invoice. Your team tracks every nonunion claim without a separate payer portal.

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Conclusion

Nonunion coding comes down to one decision. Confirm that imaging and clinical documentation support K rather than D or G before you code the visit. ICD-10 Code S92.209K is the correct code when that confirmation exists and the foot laterality is not documented. When laterality is known, use S92.201K or S92.202K to avoid audit exposure.

For practices managing complex fracture aftercare, Pabau submits the coded claim, checks eligibility, and tracks status through to remittance. That leaves coders more time for documentation accuracy. Book a demo to see how Pabau supports fracture billing workflows.

Continue your research

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Supplying a walker during nonunion treatment? E0159 explains how brake attachments are billed and what payers expect to see.

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