ICD-10 Code S62.349B: Nondisplaced metacarpal base open fracture

Key takeaways

ICD-10 Code S62.349B is a billable FY2026 code for a nondisplaced fracture of the base of an unspecified metacarpal bone.

The 7th character B marks an initial encounter for an open fracture. The operative or clinical record decides between A and B.

Unspecified metacarpal bone means the bone was never documented, not that every metacarpal is fractured.

A named bone in the chart moves the claim to S62.341B through S62.344B instead.

Practice management software like Pabau links diagnosis codes to the encounter record, so open-fracture wording carries through to the claim.

ICD-10 Code S62.349B is a billable diagnosis code for a nondisplaced fracture of the base of an unspecified metacarpal bone. It applies at the initial encounter for an open fracture. Five qualifiers have to line up in the record. Those are nondisplaced, base location, unspecified bone, open fracture, and initial encounter.

This reference page covers the full code description, the 7th character rules, and the code hierarchy. It also covers sibling codes, clinical context, and the documentation S62.349B needs in the FY2026 ICD-10-CM edition.

Effective October 1, 2025, this code is valid for claims submitted under the FY2026 ICD-10-CM edition. Coders at orthopedic practices, emergency departments, and sports medicine practices see metacarpal fractures regularly, and encounter-type assignment is where most denials start.

Claims management software that ties the code to the encounter record catches a missing open-fracture note before submission.

ICD-10 Code S62.349B: Definition, billable status, and effective date

ICD-10 Code S62.349B has one official description: Nondisplaced fracture of base of unspecified metacarpal bone, initial encounter for open fracture.

The CDC/NCHS ICD-10-CM web tool confirms it as a valid, billable diagnosis code for FY2026, effective October 1, 2025. Every term in the description carries a coding consequence.

Breaking down each term:

• Nondisplaced means the fractured bone fragments remain in anatomical alignment.
• Base refers to the proximal end of the metacarpal, nearest the wrist.
• Unspecified metacarpal bone applies when the clinical record does not identify which of metacarpal bones 2 through 5 is fractured.
• Initial encounter means the patient is receiving active treatment for the fracture.
• Open fracture means the skin was breached by the bone or by an external object at the fracture site.

The base code S62.349 is non-billable on its own. A 7th character is required to make it billable. S62.349B is one of seven valid 7th character extensions for this base.

Understanding the 7th character: B for open fracture initial encounter

In ICD-10-CM fracture coding, the 7th character carries the encounter type. According to the CMS ICD-10 coding guidelines, traumatic fracture codes in categories S00-T88 require a 7th character that classifies the episode of care.

For S62.349, character B means the patient is seen for active treatment of an open fracture for the first time.

All 7th character options for S62.349

A common coding error is assigning S62.349A (closed fracture) when the operative report clearly documents an open wound. The distinction between A and B is clinical, not administrative.

If the emergency department note or operative report describes skin disruption at the fracture site, 7th character B applies. Every follow-up visit to monitor healing or remove a cast uses 7th character D, not B. Only the first active-treatment visit uses A or B.

Code hierarchy and classification

ICD-10 Code S62.349B sits at the seventh level of the ICD-10-CM hierarchy. Understanding where it lives helps coders apply parent-code rules correctly and identify related codes quickly. The WHO ICD-10 browser provides the international framework that ICD-10-CM is derived from.

The S62 category covers all fractures at the wrist and hand level. S62.3 narrows to unspecified or other metacarpal bones. Practices managing hand injury follow-up in physical therapy settings work mostly in subsequent encounter codes. Those codes (D, G, K, P) follow the initial visit that assigned A or B.

Sibling and related metacarpal fracture ICD-10 codes

The sibling codes for S62.349B are the other 7th character extensions of S62.349, plus the specific-bone equivalents for the 2nd through 5th metacarpals. The AAPC ICD-10-CM code lookup provides a searchable reference for the full S62.3 family.

If the imaging report or operative note names the specific metacarpal, use the bone-specific code instead of S62.349B. Those codes run from S62.341B through S62.344B. The unspecified code is appropriate only when the documentation genuinely omits which bone is involved.

Practices using structured patient records are less likely to leave the bone unidentified, because digital fields prompt for anatomical detail during documentation.

Clinical overview: Metacarpal base fractures

Metacarpal base fractures account for a meaningful share of hand injuries seen in emergency and orthopedic settings.

The base of the metacarpal is the proximal end, the bony flare that connects the shaft to the carpal bones at the wrist. Fractures here typically result from axial load (a punch or fall onto a closed fist) or direct crush trauma.

A nondisplaced fracture at the base means the cortical surfaces have not shifted out of alignment on imaging. Open fractures at the metacarpal base are less common than closed injuries.

They carry a higher infection risk, because the wound communicates with the fracture site. Fractures of metacarpal bones 2 through 5 are relevant here; the 1st metacarpal (thumb) uses a separate code family (S62.2-).

• Common mechanism: direct impact or axial load to the dorsal hand
• Imaging: plain radiographs in two or three views confirm nondisplacement and base location
• Open vs. closed: the wound must communicate with the fracture site to qualify as open. A laceration elsewhere on the hand does not make the fracture open
• Initial treatment: wound irrigation, debridement, and stabilization; specific protocols vary by institution and fracture pattern

Practices that handle post-fracture rehabilitation, including hand therapy and physical therapy, move to subsequent encounter codes once active treatment ends. A later visit for a nonunion follows the same logic as S52.262K in the forearm. The 7th character B applies only at the initial treatment visit.

ICD-10 coding guidelines for metacarpal fractures

The ICD-10-CM Official Guidelines for Coding and Reporting, maintained by CMS and NCHS, govern how fracture codes are assigned. The rules below apply specifically to traumatic fractures in the S62 category.

Documentation requirements for accurate code assignment

Five documentation elements must appear in the clinical record to support ICD-10 Code S62.349B without a payer query:

1. Fracture type (open): the provider note or operative report must document an open fracture or describe a wound communicating with the fracture site. “Open fracture” in the assessment or diagnosis section is the clearest language.
2. Displacement status (nondisplaced): the radiology or operative report must state that fragments remain in alignment. “Nondisplaced” in the imaging impression is sufficient.
3. Location (base of metacarpal): the note must specify the fracture is at the base (proximal end), not the shaft or head. “Proximal metacarpal” or “metacarpal base” both support this qualifier.
4. Bone identity or absence of specificity: if the specific bone (2nd through 5th) is not named, S62.349B is appropriate. If a bone is named, use the bone-specific code.
5. Encounter type (initial): this is the first visit for active treatment. A follow-up for wound check without new active management is a subsequent encounter (7th character D).

Practices managing hand injuries benefit from digital intake forms that capture anatomical detail at the first visit. That detail keeps an unspecified code out of a record where the specific bone was known. Tight documentation workflows at the point of care are the first defense against undercoding and payer queries.

One additional rule from the official guidelines: fractures not specified as open or closed are defaulted to closed (7th character A) by convention. This means the provider must explicitly document “open” for S62.349B to be justified. An absent note does not support character B.

When to use S62.349B vs similar codes

Choosing the right code in the S62.34x family requires a quick checklist. The decision table below covers the four most common selection errors coders encounter at ICD-10 Code S62.349B and adjacent codes.

The single most costly error in this code family is assigning S62.349A when the record clearly documents an open fracture.

Many payers apply clinical edits that flag a closed-fracture code submitted alongside a debridement CPT code, triggering an audit. Keeping the diagnosis code aligned with the documented fracture type prevents that conflict.

How Pabau keeps open-fracture detail on the claim

In most practices the coder opens the chart after the visit is over. The operative note sits in one system and the claim is built in another. Anything the provider left vague, including whether the fracture was open, becomes a query days later.

Practice management software like Pabau holds the clinical note and the diagnosis code in the same encounter record. The coder reads the wound description and assigns S62.349B without leaving the chart. The code then travels into the claim with the note that justifies it.

That matters most for the A-versus-B decision. When the open-fracture wording sits beside the code field, a closed-fracture code is much harder to submit by accident. Practices weighing a clearinghouse against an integrated system can compare Pabau and Waystar on claims handling.

Reduce coding errors with integrated documentation

Pabau links diagnosis codes directly to the patient encounter record. Coders see the clinical note, the treatment, and the code in one place, so open-fracture designations never get dropped at submission.

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Conclusion

Open fracture documentation is where metacarpal coding claims go wrong. When the clinical record supports ICD-10 Code S62.349B, every qualifier matters: nondisplaced, base location, unspecified bone, open fracture, initial encounter. A single missing or incorrect qualifier lands the claim on the wrong code and starts a denial cycle.

Coders who read the wound description before choosing the 7th character rarely land on the wrong code. The fix is a documentation habit, not a billing rule. Book a demo to see how Pabau carries clinical documentation from the first encounter through to final submission.

Continue your research

Need a compliant documentation workflow for hand injuries? HIPAA compliance for medical offices covers the data-handling standards behind every patient encounter record.

Wondering how sequela codes differ from initial encounters? V86.54XS walks through the 7th character S and late-effect reporting.

Documenting an injury with an external cause? W49.09XD explains encounter-type selection in the external cause chapter.

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