ICD code S02.620B – Subcondylar mandible fracture, open

Key takeaways

ICD-10 code S02.620B is a valid, billable FY2026 ICD-10-CM code covering open subcondylar process fractures of the mandible at an initial encounter only.

The 7th character B signals an open fracture at an initial encounter. Using A or D when the operative note says otherwise triggers audit flags.

Documentation must state the open fracture, the subcondylar location, the mechanism of injury, and the encounter type. Imaging reports alone do not satisfy payer medical necessity rules.

Claims management software like Pabau submits and tracks S02.620B claims through Claim.MD in the US. Your coders still choose every code.

ICD-10 code S02.620B: definition, validity, and hierarchy

ICD-10 code S02.620B describes a fracture of the subcondylar process of the mandible that is open and occurs at an initial encounter. It is valid for FY2026 billing under the CMS ICD-10-CM coding framework and carries no age or sex edits. The hierarchy runs S00-S09 (head injuries) to S02 (fracture of skull and facial bones), then S02.6 (fracture of mandible). From there it narrows to S02.62 (subcondylar process), S02.620 (unspecified side), and S02.620B (open, initial encounter).

The same 7th character logic applies across every fracture code in the S00-S09 block. Reading the parent category first keeps skull fracture exclusion notes from being applied to mandibular injuries.

Code descriptor and clinical meaning: subcondylar fractures explained

The subcondylar process is the narrow neck of the mandible that connects the condylar head to the ramus. It sits just below the condyle and is one of the most frequently fractured regions of the mandible in blunt facial trauma. High-velocity impacts, motor vehicle collisions, and falls onto the chin all transmit force through it.

Clinically, an open subcondylar fracture means the fracture communicates with the external environment, typically through a skin laceration or an intraoral wound. This is distinct from a closed fracture where the skin remains intact. The ICD-10-CM designation of “open” must reflect the treating clinician’s intraoperative or emergency department findings, not radiographic interpretation alone.

Patients typically present with trismus, deviation of the mandible toward the affected side, malocclusion, preauricular pain, and swelling. Imaging confirms the subcondylar location before coding is finalized, and CT with 3D reconstruction is now the standard study.

Breaking down S02.620B: character-by-character structure

Each character segment in S02.620B carries a specific meaning within the ICD-10-CM classification. The table below maps every segment to its clinical or administrative significance.

The 6th character 0 signals unspecified laterality. If imaging or the operative report identifies the right or left side, use S02.621x (right) or S02.622x (left) instead. Defaulting to the unspecified code when laterality is documented is a common audit finding.

S02.620B vs adjacent mandible fracture codes

Choosing the wrong adjacent code accounts for the majority of S02.62x claim edits. The most frequent error is selecting S02.620A (closed, initial) when the operative report documents wound debridement or an open repair. Coders reach for it because the fracture looked non-displaced on imaging. Open versus closed is decided by the clinician’s findings rather than by the radiology report.

The chart below maps each documented scenario to the 7th character it produces, before the table sets out the full descriptors.

Includes, excludes, and use additional code notes for S02.620B

S02.620B inherits its Includes and Excludes notes from the S00-T88 chapter and the S00-S09 block. Review both levels before submitting, because they govern what can appear on the same claim.

• Includes (block S00-S09): Injuries of the jaw, the temporomandibular joint area, the oral cavity, and the face are all classified here. S02 then narrows that to fractures of the skull and facial bones.
• No Excludes1 applies: Neither the S00-T88 chapter nor the S00-S09 block carries an Excludes1 note. No code is barred from sharing a claim with S02.620B on that basis.
• Excludes2 (chapter S00-T88): Birth trauma (P10-P15) and obstetric trauma (O70-O71). An Excludes2 note allows both codes on one claim when both conditions are documented.
• Excludes2 (block S00-S09): Burns and corrosions (T20-T32), effects of foreign body in ear (T16), and effects of foreign body in larynx (T17.3). Each may be coded additionally when the record documents it alongside the fracture.
• Category note (S02): A fracture not indicated as open or closed is coded to closed. That default is why an operative note stating “open” matters so much for S02.620B.
• Use additional code (when applicable): An external cause code from V00-Y99 identifying the mechanism of injury. Examples include a motor vehicle accident, an assault, or a fall. Payers routinely request these on trauma claims, and omitting them can trigger medical necessity reviews.
• Use additional code (when applicable): Retained foreign body status (Z18.-) if foreign material is documented in the fracture site.

Documentation requirements for S02.620B

Every element of the ICD-10 code must be traceable to the clinical record. “Open fracture, initial encounter” is a three-part designation: each part needs its own supporting entry. Coders relying solely on radiology reports to assign S02.620B risk under-documentation findings on audit. The following elements must appear explicitly in the physician or surgeon note.

• Open fracture confirmation: The attending or operating note must use the word “open” or describe wound communication. A phrase such as “intraoral laceration exposing fracture site” qualifies. An imaging report using “displaced” or “comminuted” does not establish open status.
• Anatomical location: The note must specify “subcondylar process” or “subcondylar region.” “Condylar fracture” alone defaults to S02.61x. If the radiologist uses “condylar” but the surgeon’s exposure confirms subcondylar anatomy, the surgeon’s operative note governs.
• Laterality (if known): Right, left, or bilateral must be documented to avoid the unspecified code. If the record is genuinely silent on side, S02.620B is correct; using it when laterality is documented is an avoidable error.
• Encounter type: “Initial encounter” means the patient is receiving active treatment for the fracture for the first time. Subsequent follow-up visits switch to D/G/K/S as appropriate. Multiple visits during active treatment can retain “B” if treatment is ongoing.
• Mechanism of injury: Required for the accompanying external cause code. Document the event, activity, and place of occurrence (e.g., “unrestrained driver in frontal collision on public road”).
• Treatment rendered: Conservative management, intermaxillary fixation, or open reduction with rigid fixation must be recorded to support medical necessity for the paired CPT code.

Pairing S02.620B with the right CPT codes for mandible fracture repair

The CPT code must reflect the treatment rendered, not the fracture’s severity. An open fracture does not automatically require an open CPT procedure code. Payers cross-reference the ICD-10 open or closed designation against the CPT treatment approach; a mismatch will not always trigger denial if documented.

US practices billing electronically submit through Claim.MD, which transmits and tracks the claim. Pabau’s claims management software assembles that claim and follows its status — it does not decide or validate which ICD-10 and CPT codes belong together.

Coverage turns on the operative documentation, per AAPC coding guidance. Verify the procedure note matches the selected CPT before submission. Multi-approach repairs move to 21470, which carries its own documentation requirements.

Payer coverage and prior authorization for subcondylar fracture repair

Coverage for subcondylar fracture treatment is generally available under medical benefits for trauma cases. Oral and maxillofacial injuries sit at a benefit-routing boundary, so verify which benefit category applies before you submit.

• Medical vs dental benefit routing: Subcondylar fractures resulting from trauma are typically covered under medical benefits rather than dental. Some commercial plans categorize any jaw-related treatment as dental, with different cost-sharing and prior authorization requirements. Confirm the benefit category with the payer before surgery.
• Prior authorization triggers: Open treatment (CPT 21454, 21461, 21462, 21470) commonly requires prior authorization from commercial insurers and Medicare Advantage plans. Closed treatment (CPT 21450, 21451, 21453) is less likely to need pre-approval, though this varies by plan. Obtain authorization for any planned operative case.
• Medicare coverage: Medicare Part B generally covers treatment of traumatic mandibular fractures under the Physician Fee Schedule. That holds when an oral and maxillofacial surgeon or a general surgeon performs the repair. Coverage rules change with annual Local Coverage Determination updates. Check the CDC/NCHS ICD-10-CM tool and your MAC’s LCD database for current guidance.
• Medical necessity documentation: Payers require imaging (CT preferred), clinical findings, and a documented treatment rationale. “Open fracture” alone is insufficient; document why the chosen treatment approach was selected over alternatives.

Common claim denial reasons and how to avoid them for S02.620B

Subcondylar fracture claims attract a predictable set of denial patterns. The most preventable ones relate to the 7th character and the open or closed designation. Those are documentation failures transcribed into coding errors, so the clean claim check belongs at documentation time.

The medical billing denial codes reference lists the CARC and RARC reason codes commonly paired with S02.x claims.

ICD-9-CM crosswalk for S02.620B

ICD-9-CM did separate subcondylar fractures from condylar ones, and it separated open from closed. What it could not carry was encounter type or laterality, so the GEMs crosswalk is approximate rather than exact.

That matters for legacy record review and audit lookbacks against current coding standards. Full GEMs documentation is available via the ResDAC ICD codes in Medicare files reference.

When reviewing pre-2015 claims, 802.32 is the code that corresponds to S02.620B. Do not treat the GEMs crosswalk as a coding authority for current claims. It is a legacy reference tool only.

How Pabau keeps S02.620B coding and claim submission on one record

A practice coding facial trauma often works across three systems. The operative note sits in the EHR, the coder works from a separate worksheet, and the claim is keyed into a clearinghouse portal. Every hand-off is a chance for the 7th character to drift away from what the surgeon documented.

Pabau, practice management software for medical and aesthetic practices, keeps the note, the coded diagnosis, and the claim on one patient record. Your coder assigns S02.620B against the operative note in the same system that holds it. Claim.MD then submits the claim in the US and returns its status.

The software does not pick your codes or check an ICD-CPT pairing for you. What it removes is the re-keying between systems, which is where a documented laterality or an initial-encounter character usually gets lost.

Keep S02.620B claims consistent from note to payer

Pabau holds the operative note, the assigned codes, and the claim on one patient record. It submits through Claim.MD in the US and tracks the response.

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Conclusion

The core challenge with S02.620B is rarely finding the code. The three-part designation of open, subcondylar, and initial encounter has to hold up in every field of the claim.

The ICD-10 code, the operative note, the imaging report, and the CPT selection must tell the same story. One inconsistency is enough for a denial or a compliance flag.

Fix the documentation first and the coding follows. Build the six-element check into your operative note template, and the 7th character stops being a judgment call at billing time. Book a demo to see how Pabau keeps fracture coding and claim submission on one record.

Continue your research

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Want fewer rejections at first pass? Clean claim submission explains what a payer needs on a first submission.

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