2026 ICD-10-CM Diagnosis Code S00.502AUnspecified superficial injury of oral cavity, initial encounter

ICD-10-CM Codes›S00–T88›S00-S09›S00

ICD-10-CM S00.502A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S00.502A is a billable ICD-10-CM diagnosis code for unspecified superficial injury of oral cavity, 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Superficial injury; contusion, initial encounter.

Code Identity

ICD-10-CM Code
S00.502A
Billable Status
Yes — Valid for Submission
Code Describes
Unspecified superficial injury of oral cavity, initial encounter
Short Description
Unspecified superficial injury of oral cavity, init encntr
Parent Code
S00.502
Unspecified superficial injury of oral cavity

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS00-S09Injuries to the head
CategoryS00Superficial injury of head
This CodeS00.502AUnspecified superficial injury of oral cavity, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Arrest of growth of root of tooth due to and following dental trauma
  • Continued root development of immature permanent tooth following dental trauma
  • Dental sequestrum
  • Dilaceration of crown of permanent tooth due to and following dental trauma
  • Dilaceration of tooth
  • Disorder of eruption of permanent tooth due to and following dental trauma
  • Duplication of root of permanent tooth due to and following dental trauma
  • Friction injury of tooth extending into dentine
  • Friction injury of tooth extending into pulp
  • Friction injury of tooth limited to enamel
  • Gingival disease due to traumatic injury
  • Infraocclusion of tooth due to and following dental trauma
  • Injury of periodontal tissue
  • Injury of teeth
  • Internal resorption of tooth
  • Internal resorption of tooth following dental trauma
  • Intrinsic staining of tooth due to and following dental trauma
  • Metaplasia of pulp of tooth following dental trauma
  • Occlusal trauma
  • Oral cavity, dental and salivary gland disorder
  • Oral cavity, dental and salivary gland injury
  • Partial arrest of growth of root of tooth due to and following dental trauma
  • Resorption of alveolar process due to dental trauma
  • Sequestrum of permanent tooth bud due to and following dental trauma
  • Submerging tooth
  • Superficial injury of gum
  • Superficial injury of gum with infection
  • Superficial injury of mouth
  • Superficial injury of palate
  • Superficial injury of tongue
  • Supernumerary root of tooth
  • Transient internal resorption of tooth due to and following dental trauma

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Superficial injury of head (S00). 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.

CCSR INJ017
Superficial injury; contusion, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Mouth Disorders

Your mouth is one of the most important parts of your body. It has many different functions. It allows you to:

Read the full article at MedlinePlus

Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.

Convert S00.502A to ICD-9-CMHistory

The closest ICD-9-CM equivalents under the General Equivalence Mappings.

ICD-9-CM
910.8 Superfic inj head NEC
Approximate The match is approximate rather than exact.

Code HistoryHistory

FY 2016AddedAdded to the ICD-10-CM code setEffective October 1, 2015, the first year of ICD-10-CM.
FY 2017–2025No changes
FY 2026CurrentCurrent code set, no changesEffective October 1, 2025 through September 30, 2026.

Questions About S00.502AOverview

Is S00.502A (Unspecified superficial injury of oral cavity) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report unspecified superficial injury of oral cavity, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in S00.502A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for unspecified superficial injury of oral cavity, such as an emergency visit or first evaluation.

What MS-DRG does S00.502A group to?

When unspecified superficial injury of oral cavity, 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 S00.502A?

Under the General Equivalence Mappings, unspecified superficial injury of oral cavity, initial encounter converts to ICD-9-CM 910.8 (superfic inj head NEC). 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.