2026 ICD-10-CM Diagnosis Code S01.459AOpen bite of unspecified cheek and temporomandibular area, initial encounter
S01.459A is a billable ICD-10-CM diagnosis code for open bite of unspecified cheek and temporomandibular area, initial encounter. The 7th character A marks it as an initial encounter code, used while the patient is receiving active treatment. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 604 through 605, 963 through 965. Coders also document this condition as animal bite of cheek. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Any dental condition including traumatic injury; and Open wounds of head and neck, initial encounter.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Animal bite of cheek
- Dog bite of cheek
- Dog bite of face
- Human bite of cheek
- Human bite of face
Coding GuidelinesGuidance
The appropriate 7th character is to be added to each code from block Open wound of head (S01). Use the following options for the applicable episode of care:
- A - initial encounter
- D - subsequent encounter
- S - sequela
Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.
Clinical ClassificationClinical
AHRQ’s CCSR groups this code into broader clinical categories.
Patient EducationClinical
Animal Bites
Wild animals usually avoid people. They might attack, however, if they feel threatened, are sick, or are protecting their young or territory. Attacks by pets are more common. Animal bites rarely are life-threatening, but if they become infected, you can develop serious medical problems.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert S01.459A to ICD-9-CMHistory
Code HistoryHistory
Questions About S01.459AOverview
Is S01.459A (Open bite of unspecified cheek and temporomandibular area) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report open bite of unspecified cheek and temporomandibular area, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in S01.459A mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for open bite of unspecified cheek and temporomandibular area, such as an emergency visit or first evaluation.
What MS-DRG does S01.459A group to?
When open bite of unspecified cheek and temporomandibular area, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 604, 605, 963, 964, 965, with relative weights from 0.9160 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of S01.459A?
Under the General Equivalence Mappings, open bite of unspecified cheek and temporomandibular area, initial encounter converts to ICD-9-CM 873.41 (open wound of cheek) and 873.44 (open wound of jaw). The mapping is approximate, so confirm the match fits the documentation.
Footnotes
[1] Not chronic - A diagnosis code that does not fit the criteria for chronic condition (duration, ongoing medical treatment, and limitations) is considered not chronic. Some codes designated as not chronic are acute conditions. Other diagnosis codes that indicate a possible chronic condition, but for which the duration of the illness is not specified in the code description (i.e., we do not know the condition has lasted 12 months or longer) also are considered not chronic.
