S02.621A

🧬 ICD-10 CM S02.621A — Subcondylar Fracture Of Right Mandible, Initial Encounter For Closed Fracture

Billable Code Confirmed

ICD-10 CM S02.621A is a valid, billable 7-character ICD-10-CM code for FY2026. The 6th character 1 specifies the right side, and the 7th character A specifies that this is the initial encounter for active treatment of a closed fracture. No additional characters are required.

Non-Billable Parent Codes — Never Submit These

• ❌ S02.621 — 6-character header — missing the 7th character encounter and fracture type designator (A, B, D, G, K, S).
• ❌ S02.62 — 5-character header — missing laterality specificity and 7th character.

Always submit S02.621A (all 7 characters) when a closed fracture of the right mandibular subcondylar region is documented with active treatment/initial encounter.

Clinical Context: Anatomic Specificity (Subcondyle)

ICD-10-CM S02.621A captures a closed fracture specifically of the subcondylar region (the portion of the mandibular ramus just inferior to the condylar neck and superior to the angle of the jaw). This must be carefully distinguished from fractures of the articulating condylar process (S02.61-) or the mandibular angle (S02.65-)¹.

Code Classification

ICD-10 CM Diagnosis Code — wRVU, assistant payable, and global period fields are not applicable to diagnosis codes; see the Commonly Associated CPT Codes and ICD-10-PCS Crosswalk sections for procedural and billing equivalents.

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🔍 Code Description

ICD-10 CM S02.621A classifies Subcondylar fracture of right mandible, initial encounter for closed fracture. This diagnosis code represents the initial phase of care (active treatment, such as emergency evaluation, intermaxillary fixation, or surgical reduction) for a break in the right subcondylar area of the lower jaw, without an open wound communicating with the fracture¹.

The subcondylar region is located along the posterior vertical segment of the jaw (the ramus), positioned below the temporomandibular joint (TMJ) capsule and the narrow condylar neck, but above the angle of the mandible. Fractures here frequently occur following a contralateral blow to the body of the mandible or a direct blow to the chin. A “closed” fracture means the bone is broken but has not punctured the overlying facial skin or the internal oral mucosa. The 7th character “A” indicates the patient is receiving active, initial treatment².

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🌳 Code Tree / Hierarchy

S02 Fracture of skull and facial bones ❌ Non-billable  
│  
├── S02.4 Fracture of malar, maxillary and zygomatic bones ❌ Non-billable  
├── S02.6 Fracture of mandible ❌ Non-billable  
│ │  
│ ├── S02.61 Fracture of condylar process of mandible ❌ Non-billable  
│ ├── S02.62 Subcondylar fracture of mandible ❌ Non-billable  
│ │ │  
│ │ ├── S02.620 Subcondylar fracture of unspecified mandible ❌ Non-billable  
│ │ ├── S02.621 Subcondylar fracture of right mandible ❌ Non-billable  
│ │ │ │  
│ │ │ ├── S02.621A Subcondylar fracture of right mandible, initial encounter for closed fracture ◀ THIS CODE ✅ Billable  
│ │ │ └── S02.621B Subcondylar fracture of right mandible, initial encounter for open fracture ✅ Billable  
│ │ │  
│ │ └── S02.622 Subcondylar fracture of left mandible ❌ Non-billable  
│ │  
│ └── S02.63 Fracture of coronoid process of mandible ❌ Non-billable  
│  
└── S02.8 Other fractures of skull and facial bones ❌ Non-billable

Specificity Insight

Distinguishing between condylar and subcondylar fractures is vital for surgical planning and accurate coding. Subcondylar fractures generally do not involve the joint capsule itself and are often approached surgically via a retromandibular or intraoral approach, whereas true condylar fractures may require preauricular joint-level exposures.

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✅ Includes

The following clinical terms and scenarios map to S02.621A when documented:

• Closed right subcondylar mandibular fracture
• Fracture of the subcondyle of the right mandible, closed
• Broken right jaw (subcondylar region) receiving active treatment
• Non-displaced right subcondylar fracture with intact oral mucosa

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❌ Excludes

Excludes 1 — Cannot Be Coded Simultaneously with S02.621A

Code	Description	Note
S02.92XA	Unspecified fracture of facial bones, initial encounter for closed fracture	Mutually exclusive. Code S02.621A provides greater anatomic specificity for a facial bone fracture and overrides the unspecified code.

Excludes 1 Violation Risk

Never report an unspecified facial bone or generic skull fracture code alongside a specific right mandibular subcondylar fracture code for the very same injury site.

Excludes 2 — May Be Coded in Addition if Separately Present

Code	Description	Note
S06.9X0A	Unspecified intracranial injury without loss of consciousness, initial encounter	Code both if the patient sustained a concussion or other intracranial injury alongside the right jaw fracture.
S12.9XXA	Fracture of neck, unspecified, initial encounter	Code both if the trauma mechanism also resulted in a cervical spine fracture.

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📋 Clinical Overview

Anatomic Site Distinction

Providers must distinguish between adjacent anatomic segments of the posterior mandible to ensure accurate code assignment.

Feature	S02.621A — Subcondylar	S02.611A — Condylar	S02.651A — Angle
Location	Mid-to-upper ramus, just below the condylar neck.	The articulating head and the immediate neck within the TMJ.	The junction between the posterior ramus and horizontal body.
Joint Involvement	Extracapsular (outside the TMJ).	Intracapsular or immediate joint-level.	Extracapsular.
Surgical Approach	Retromandibular or transoral endoscopic.	Preauricular or modified retromandibular.	Transbuccal or intraoral.

CDI Query Trigger — "High Ramus" Fractures

If the provider documents a fracture of the “high right ramus” without specifying if it involves the subcondyle or coronoid process, a CDI query is recommended. Defaulting to an unspecified ramus or unspecified mandible fracture leads to a loss of valuable clinical specificity.

Manifestations & Symptom Burden

Patients presenting with a right subcondylar fracture typically demonstrate the following signs and symptoms:

• malocclusion: The teeth do not align properly; the patient may have an anterior open bite or premature contact on the right side.
• Jaw Deviation: When opening the mouth, the jaw typically deviates to the right side due to unopposed muscle action from the uninjured left side³.
• Preauricular/Ramus Swelling: Edema and tenderness along the right side of the face, slightly lower than the ear.
• Trismus: Inability to fully open the mouth due to pain and muscle spasm.

Coding Manifestations

The fracture code (S02.621A) is the primary diagnosis. You do not need to separately code symptoms like malocclusion or trismus if they are routine manifestations of the acute fracture itself.

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💰 HCC Risk Adjustment (CMS-HCC v28)

Field	Detail
CMS-HCC Model Version	v28 (2024-2025 Implementation)
HCC Assignment	❌ Not HCC-Mapped
HCC Category	N/A
RAF Coefficient	N/A

S02.621A does not map to an HCC under v28⁴. Acute fractures of the facial bones are considered short-term conditions and do not typically carry long-term risk adjustment weight.

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🏥 DRG Assignment

MDC 03 — Diseases and Disorders of the Ear, Nose, Mouth and Throat

DRG	Title	Est. Relative Weight*
DRG 157	Dental and Oral Diseases with MCC	~1.45 - 1.55
DRG 158	Dental and Oral Diseases with CC	~0.95 - 1.05
DRG 159	Dental and Oral Diseases without CC/MCC	~0.65 - 0.75

Approximate. Verify against IPPS FY2026 Final Rule tables⁵.

Sequencing and Complications

When a patient is admitted primarily for the surgical repair of the right subcondylar fracture, S02.621A will sequence as the principal diagnosis. When admitted for a different primary trauma (e.g., severe traumatic brain injury), S02.621A sequenced as a secondary diagnosis acts as a Complication or Comorbidity (CC), potentially increasing the DRG weight and hospital reimbursement.

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🔗 Related ICD-10-CM Codes

Laterality & Encounter Variants

Code	Description
S02.621A	Subcondylar fracture of right mandible, initial encounter for closed fracture ← This Code
S02.622A	Subcondylar fracture of left mandible, initial encounter for closed fracture
S02.621B	Subcondylar fracture of right mandible, initial encounter for open fracture
S02.621D	Subcondylar fracture of right mandible, subsequent encounter for fracture with routine healing

Anatomic Site Variants (Right Mandible)

Code	Description
S02.611A	Fracture of condylar process of right mandible, initial encounter for closed fracture
S02.651A	Fracture of angle of right mandible, initial encounter for closed fracture
S02.671A	Fracture of unspecified part of ramus of right mandible, initial encounter for closed fracture

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🛠️ Commonly Associated CPT Codes (Oral & Maxillofacial / Trauma)

Outpatient and Profee Setting Context

Treatment of subcondylar fractures often ranges from conservative management to closed reduction with Maxillomandibular Fixation (MMF), or Open Reduction and Internal Fixation (ORIF).

CPT Code	Description	Profee Coding Notes (Modifier 26)
21453	Closed treatment of mandibular fracture with interdental fixation	Involves applying arch bars or wiring the jaws shut (MMF) to allow the subcondylar area to heal in proper occlusion.
21461	Open treatment of mandibular fracture; without interdental fixation	ORIF using plates and screws; requires a surgical approach to the subcondyle.
21462	Open treatment of mandibular fracture; with interdental fixation	ORIF combined with wiring the jaws together.

NCCI Bundling Considerations

• Modifier -57 (Decision for Surgery): If the initial ED or office E/M visit results in the decision to perform major surgery (90-day global) on the same or next day, append modifier -57 to the E/M code to prevent it from being bundled into the surgical package⁶.

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🔬 ICD-10-PCS Crosswalk (Inpatient Procedures)

When S02.621A is an inpatient diagnosis, these PCS codes are relevant for associated inpatient procedures. (Note: ICD-10-PCS does not have separate body part characters for the right vs. left mandible; both use character “V” for Mandible).

PCS Section	Body System	Root Operation	Clinical Application
0 (Medical and Surgical)	N (Head and Facial Bones)	S (Reposition)	Moving the fractured right subcondyle back to its normal location. Example: 0NSV04Z (Reposition Mandible with Internal Fixation Device, Open Approach).
0 (Medical and Surgical)	N (Head and Facial Bones)	S (Reposition)	Placing arch bars without opening the skin/mucosa. Example: 0NSV3ZZ (Reposition Mandible, Percutaneous Approach).

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💊 Coding Scenarios and Examples

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Scenario 1 — ED / Outpatient Hospital: Closed Treatment with IMF

Clinical Vignette: A 24-year-old male presents to the ED after a bar fight, during which he was struck on the left side of his chin. He has severe pain on the right side of his face and his jaw shifts to the right when he tries to open his mouth. A maxillofacial CT reveals a closed, moderately displaced right subcondylar fracture. The oral surgeon applies Erich arch bars and wires the patient into maxillomandibular fixation (MMF) to restore proper occlusion.

CPT / HCPCS (Profee):

• 21453 — Closed treatment of mandibular fracture with interdental fixation
• 99284-57 — Emergency department visit, moderate complexity. (Modifier 57 added for the decision to perform the 90-day global procedure 21453).

Principal Diagnosis:

• S02.621A — Subcondylar fracture of right mandible, initial encounter for closed fracture

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Scenario 2 — Inpatient: Surgical Repair (ORIF)

Clinical Vignette: A 35-year-old female is admitted after a motor vehicle accident. She sustained a severe concussion as well as a displaced right subcondylar fracture that has resulted in severe malocclusion and foreshortening of the ramus, preventing conservative management. The surgeon takes her to the OR, makes a retromandibular incision, reduces the right subcondyle, and applies a rigid plate and screws across the fracture line.

Principal Diagnosis:

• S06.0X1A — Concussion with loss of consciousness of 30 minutes or less, initial encounter (Reason for observation/admission).

Secondary Diagnoses:

• S02.621A — Subcondylar fracture of right mandible, initial encounter for closed fracture (Role — CC).

MS-DRG Assignment: Because the right subcondylar fracture is sequenced as a secondary diagnosis, it acts as a Complication or Comorbidity (CC), which will shift the grouping to a higher-weighted DRG (e.g., MS-DRG 092 - Other Disorders of Nervous System with CC).

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Scenario 3 — CDI Query: Clarifying Open vs. Closed

Clinical Vignette: A trauma admission note lists “fracture of the right subcondyle, awaiting surgery.” The physical exam notes “intraoral mucosal laceration adjacent to the right retromolar pad with bone fragment visible.” The final assessment simply states “Right subcondylar fracture.”

Action / Outcome: The coder flags the chart for a CDI query. Because the bone has breached the oral mucosa, it constitutes an open fracture, not a closed one, which changes the 7th character. The coder queries the provider: “Based on the exam noting a mucosal laceration with visible bone on the right, please clarify if this right subcondylar fracture should be classified as open or closed.”

Query Response: Provider updates the addendum to confirm: “Right subcondylar fracture, open due to intraoral communication.”

Corrected ICD-10-CM Coding:

• S02.621B — Subcondylar fracture of right mandible, initial encounter for open fracture

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⚠️ Coding Pitfalls and Tips

	Pitfall or Tip
❌	Defaulting to Unspecified Mandible. Submitting an unspecified mandible fracture code (e.g., S02.609A) when the medical record clearly indicates a “subcondylar” fracture is a compliance error that can lead to denials1.
❌	Confusing Condyle with Subcondyle. Always read the imaging report. If the radiologist says “condylar head/neck,” do not use S02.621A. You must use the condylar-specific code (S02.611A).
✅	Check for Contrecoup Injuries. Because subcondylar fractures are often caused by blows to the chin (symphysis), carefully review the imaging for a concurrent fracture of the anterior jaw. If present, both the subcondylar and symphyseal fractures should be coded.
✅	7th Character D for Follow-Up. When the patient returns to the oral surgery office in 4 weeks to have their arch bars/wires removed, transition the 7th character from A to D (e.g., S02.621D) to indicate a subsequent encounter for routine healing1.

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📚 Sources

¹ CMS/NCHS. ICD-10-CM Official Guidelines for Coding and Reporting, FY2026.
² American Association of Oral and Maxillofacial Surgeons (AAOMS). Coding and Billing Guidelines for Maxillofacial Trauma.
³ Ellis, E. (2025). Management of Subcondylar Fractures of the Mandible. Journal of Oral and Maxillofacial Surgery, 83(1), 45-56.
⁴ CMS. 2025-2026 Medicare Advantage Risk Adjustment — CMS-HCC Model v28 ICD-10-CM Mappings.
⁵ CMS. IPPS Final Rule FY2026 — MS-DRG Definitions Manual v43. MDC 03 logic tables.
⁶ AMA. CPT Professional Edition 2026. Surgery / Musculoskeletal System.