ICD-10 Code S21.439D: Puncture wound thorax, subsequent encounter
ICD-10 Code S21.439D is a billable code for a puncture wound of the back wall of...
Last Updated: August 12, 2026
Key takeaways
ICD-10 code S62.606K describes a fracture of an unspecified phalanx of the right little finger, coded at a subsequent encounter where nonunion has developed.
S62.606K is a billable, specific ICD-10-CM code valid for all HIPAA-covered transactions. It became effective October 1, 2025 under the 2026 edition.
The 7th character K is the critical coding element. It separates a subsequent encounter for fracture with nonunion from initial encounters and other complication types.
Pabau’s claims management software and digital forms help orthopedic and hand practices document laterality, phalanx type, and encounter type accurately.
S62.606K is a valid, billable ICD-10-CM diagnosis code for the 2026 edition. It became effective October 1, 2025, per the CMS ICD-10 codes page. The complete official description is: Fracture of unspecified phalanx of right little finger, subsequent encounter for fracture with nonunion.
The code is specific enough to submit directly on a claim. Parent codes such as S62.606 and S62 are not billable on their own. Only the fully extended 7th-character code qualifies for reimbursement.
Understanding the 7th character K in ICD-10 fracture codes
The 7th character is what separates ICD-10 code S62.606K from every other code in the S62.606 family. Character K specifically means “subsequent encounter for fracture with nonunion.” Reading the full extension table prevents miscoding, particularly when a follow-up shifts from routine healing to confirmed nonunion.
G and K are not interchangeable. Delayed healing means bone formation is progressing more slowly than expected but is still occurring. Nonunion means the fracture site shows no evidence of progressive healing, usually confirmed radiographically after three to six months.
Use K only when nonunion is clinically and radiographically confirmed. The same 7th-character logic drives S62.211D, which covers a thumb base fracture seen at a follow-up visit.
What is a subsequent encounter for fracture with nonunion?
Nonunion is a fracture complication rather than a slow but normal healing curve. Clinically, it is declared when serial imaging shows no progressive bridging callus across the fracture. That point usually arrives three to six months after injury, though the threshold varies by bone and patient. The fracture site may remain mobile and painful.
A subsequent encounter covers any visit after the active, definitive treatment phase has ended. The patient returns for evaluation, management of complications, or follow-up imaging. Once nonunion is confirmed at a subsequent visit, K becomes the correct 7th character.
- Initial encounter (A/B): The visit at which active treatment is delivered, including casting, splinting, or surgical fixation.
- Subsequent encounter (D/G/K/P): Follow-up visits during the healing phase or for complication management.
- Sequela (S): Late effects that persist after the fracture has resolved, such as post-fracture stiffness. Wrist codes such as S62.032S use the same character.
For ICD-10 code S62.606K to apply, the record must document a return visit at which nonunion is confirmed in the right little finger’s phalanx. Initial encounters never carry 7th character K, regardless of how severe the fracture appeared at presentation.
Pro Tip
Document the specific radiographic or clinical evidence that confirms nonunion in every note where K is coded. Payers auditing subsequent-encounter fracture claims with nonunion coding often request imaging reports. A note that simply states nonunion without supporting evidence is a denial risk.
S62.606K code hierarchy and parent codes
ICD-10 code S62.606K sits at the bottom of a four-level hierarchy within the S62 block. Each parent level is not billable on its own, so only the fully extended code qualifies for claim submission. Neighboring hand codes such as S62.360G are built the same way, from block down to 7th character.
Related codes in the S62.606 family
The S62.606 family covers all encounter types for a fracture of the unspecified phalanx of the right little finger. Confusing D (routine healing) with K (nonunion) is one of the most frequent errors on orthopedic follow-up claims. ICD10Data’s S62.606 listing is a quick way to check a sibling code at the point of coding.
When documentation is ambiguous about whether healing is delayed (G) or has definitively failed (K), query the treating provider before coding. Using G when K is clinically supported results in undercoding. Using K prematurely is a compliance risk.
Clinical documentation requirements for S62.606K
Correct use of ICD-10 code S62.606K depends on four documentation elements all being present in the clinical record. Missing any one creates a coding inaccuracy and a potential audit finding. Digital intake forms that capture these elements at each follow-up keep the record complete without extra admin work.
- Laterality: The record must specify right. The same injury on the left little finger codes to S62.607K, and unspecified laterality codes to S62.609K. A note reading “little finger fracture” is not enough.
- Phalanx type: S62.606K uses “unspecified phalanx.” That fits only when documentation does not differentiate between the proximal, middle, and distal phalanx. If the chart names the phalanx, a more specific code exists and should be used.
- Encounter type: The chart must reflect a follow-up visit, not the initial treatment encounter. Operative and emergency department notes for initial fracture management carry 7th character A or B.
- Nonunion confirmation: Clinical or radiographic evidence of nonunion must be documented explicitly. A note saying the fracture is healing as expected does not support K. Imaging reports and provider assessments both meet the requirement.
The unspecified phalanx element is worth a closer look. It is a genuine clinical finding, covering ambiguity on imaging or involvement of more than one phalanx. When the clinician documents a proximal phalanx fracture of the right little finger, move to the more specific code instead.
Approximate synonyms and alternate descriptions
Coders and clinicians may encounter these clinical phrases in documentation that correspond to ICD-10 code S62.606K. Recognizing the alternate language keeps the right code in play even when the record avoids the official wording.
- Nonunion of finger phalanx fracture, right little finger, follow-up
- Fracture of right fifth digit phalanx with nonunion, subsequent visit
- Failed fracture healing, unspecified phalanx, right small finger
- Right little finger fracture nonunion, subsequent encounter
- Fracture right fifth finger, unspecified phalanx, nonunion
None of these phrases should be coded from the synonym alone. Cross-reference it against the full tabular description to confirm every coding criterion is met before assigning S62.606K. The AAPC Codify lookup searches by keyword, which helps when a dictated note uses non-standard phrasing.
How Pabau supports accurate ICD-10 coding for fracture diagnoses
Orthopedic and hand surgery practices see fracture follow-up patients across multiple encounters. Each visit can shift the 7th character, moving from D to G to K as healing status changes. Without a structured documentation workflow, coders work from notes that never record the change.
Practice management software like Pabau ties the clinical note to the claim. Its claims management software carries encounter type, laterality, and diagnosis updates straight into billing. Coders stop chasing the front desk for detail that was recorded weeks ago.
Practices running physical therapy EMR or sports medicine software workflows can build their own follow-up templates. Those templates prompt the clinician for nonunion confirmation language at every relevant visit.
Patient records store imaging notes and provider assessments in one place, so coders have the evidence they need to assign S62.606K. The CDC ICD-10-CM web tool remains the authoritative reference for confirming code validity before submission.
Pro Tip
Set up a follow-up fracture note template with a mandatory field for radiographic findings. Add a dropdown for healing status covering routine, delayed, nonunion, and malunion. Coders should never have to assume 7th character selection from a narrative note alone.
Accurate fracture coding starts with accurate documentation
Pabau captures the laterality, phalanx detail, and encounter type your coders need. Every follow-up visit is recorded the same way as the first one.
Conclusion
Getting S62.606K right is a documentation problem before it is a coding problem. Three elements have to be on the page. The right little finger, an unspecified phalanx, and nonunion confirmed at a follow-up visit.
Build the follow-up template so the clinician supplies all three, and the 7th character stops being a judgment call. The trade-off worth remembering sits between the G and K characters. Coding G when nonunion is documented undercuts the claim. Coding K before imaging supports it invites an audit. Query the provider whenever the note lands between the two.
Pabau’s documentation and billing tools help hand and orthopedic practices capture the exact language coders need at every follow-up visit. Book a demo to see how structured notes and integrated claims cut fracture coding errors.
Continue your research
Coding another fracture in the same hand? S62.011A walks through laterality and 7th-character choice for a displaced scaphoid fracture.
Working on forearm trauma claims? S52.356C shows how the open-fracture 7th characters change the code you submit.
Fighting denials on injury claims? S33.8XXS covers sequencing and the documentation payers ask to see.
Need a consistent follow-up note? Clinical progress notes gives you a template that records healing status at every visit.
Coding finger injuries beyond fractures? S61.311S explains sequela coding for a laceration with nail damage.
Frequently asked questions
What does ICD-10 code S62.606K mean?
ICD-10 code S62.606K is a billable diagnosis code for a fracture of an unspecified phalanx of the right little finger. It applies at a subsequent encounter where nonunion has been confirmed. The 7th character K marks a follow-up visit at which the fracture failed to heal. That separates it from routine healing (D), delayed healing (G), and malunion (P).
Is S62.606K a billable ICD-10 code?
Yes. S62.606K is a billable, specific ICD-10-CM code valid for use in all HIPAA-covered transactions. It became effective October 1, 2025, under the 2026 edition. Its parent codes (S62, S62.6, S62.60, S62.606) are not billable on their own.
What is the difference between 7th character K and 7th character G in S62.606?
7th character G means subsequent encounter for fracture with delayed healing, so bone formation is progressing but slower than expected. Character K means subsequent encounter for fracture with nonunion, so the fracture site shows no progressive healing. Use K only when nonunion is explicitly documented, not when healing is merely slow.
What are the related codes in the S62.606 family?
The S62.606 family covers seven codes. They are S62.606A (initial, closed), S62.606B (initial, open), S62.606D (subsequent, routine healing), and S62.606G (subsequent, delayed healing). The rest are S62.606K (subsequent, nonunion), S62.606P (subsequent, malunion), and S62.606S (sequela). All describe the unspecified phalanx of the right little finger.
How do I document a nonunion fracture of the finger for ICD-10?
Documentation must confirm four elements. Those are the laterality, the digit, the phalanx involved or that it is unspecified, and evidence of nonunion at a subsequent encounter. An imaging report showing absent callus formation supports 7th character K, and so does a provider statement of nonunion. A note that mentions only slow healing does not.
Which phalanx does S62.606K refer to?
S62.606K refers to an unspecified phalanx. The documentation does not say whether the fracture involves the proximal, middle, or distal phalanx of the right little finger. If the record identifies the phalanx, use the more precise code in the S62 family instead.
What is the code for a left little finger fracture with nonunion?
A fracture of an unspecified phalanx of the left little finger with nonunion codes to S62.607K at a subsequent encounter. When the record does not state which hand is involved, use S62.609K. Both carry the same 7th character rules as S62.606K.
