2026 ICD-10-CM Diagnosis Code S00.86XAInsect bite (nonvenomous) of other part of head, initial encounter
S00.86XA is a billable ICD-10-CM diagnosis code for insect bite (nonvenomous) of other part of head, 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 606 through 607, 963 through 965. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Superficial injury; contusion, initial encounter.
Code Identity
Code Classification
Approximate SynonymsGuidance
Alternate terms and clinical phrases that map to this code.
- Animal bite of cheek
- Animal bite of forehead
- Insect bite of cheek
- Insect bite of forehead
- Insect bite, nonvenomous, of face
- Nonvenomous insect bite of cheek
- Nonvenomous insect bite of cheek with infection
- Nonvenomous insect bite of cheek without infection
- Nonvenomous insect bite of chin
- Nonvenomous insect bite of chin with infection
- Nonvenomous insect bite of face with infection
- Nonvenomous insect bite of face without infection
- Nonvenomous insect bite of forehead
- Superficial injury of cheek with infection
- Superficial injury of cheek without infection
- Superficial injury of chin
- Superficial injury of face without infection
- Superficial injury of skin of forehead
- Wound of head due to nonvenomous insect bite
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.
Patient EducationClinical
Insect Bites and Stings
Most insect bites are harmless, though they sometimes cause discomfort. Bee, wasp, and hornet stings and fire ant bites usually hurt. Mosquito and flea bites usually itch. Insects can also spread diseases. In the United States, some mosquitoes spread West Nile virus.
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert S00.86XA to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S00.86XAOverview
Is S00.86XA (Insect bite (nonvenomous) of other part of head) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report insect bite (nonvenomous) of other part of head, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in S00.86XA mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for insect bite (nonvenomous) of other part of head, such as an emergency visit or first evaluation.
What MS-DRG does S00.86XA group to?
When insect bite (nonvenomous) of other part of head, initial encounter is the principal diagnosis on an inpatient stay, it groups to MS-DRG 606, 607, 963, 964, 965, with relative weights from 0.9064 to 2.7338 depending on complications. Higher weights mean higher Medicare reimbursement.
What is the ICD-9 equivalent of S00.86XA?
Under the General Equivalence Mappings, insect bite (nonvenomous) of other part of head, initial encounter converts to ICD-9-CM 910.4 (insect bite head). 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.
