2026 ICD-10-CM Diagnosis Code S00.92XABlister (nonthermal) of unspecified part of head, initial encounter
S00.92XA is a billable ICD-10-CM diagnosis code for blister (nonthermal) of unspecified 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. Coders also document this condition as friction blisters of the skin. 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.
- Friction blisters of the skin
- Superficial injury of head and neck
- Superficial traumatic blister of head and neck
- Traumatic blister of head
- Traumatic blister of head, infected
- Traumatic blister of neck
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
Blisters
Blisters are fluid-filled sacs on the outer layer of your skin. They form because of rubbing, heat, or diseases of the skin. They are most common on your hands and feet.
The full article covers:
- What are blisters?
- What causes blisters?
- What are the treatments for blisters?
- Can blisters be prevented?
Read the full article at MedlinePlus
Courtesy of MedlinePlus, a service of the U.S. National Library of Medicine.
Convert S00.92XA to ICD-9-CMHistory
The closest ICD-9-CM equivalents under the General Equivalence Mappings.
Code HistoryHistory
Questions About S00.92XAOverview
Is S00.92XA (Blister (nonthermal) of unspecified part of head) a billable code?
Yes. This is a billable ICD-10-CM code, specific enough to report blister (nonthermal) of unspecified part of head, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.
What does the 7th character A in S00.92XA mean?
The final character A marks the initial encounter: use it while the patient is receiving active treatment for blister (nonthermal) of unspecified part of head, such as an emergency visit or first evaluation.
What MS-DRG does S00.92XA group to?
When blister (nonthermal) of unspecified 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 S00.92XA?
Under the General Equivalence Mappings, blister (nonthermal) of unspecified part of head, initial encounter converts to ICD-9-CM 910.2 (blister 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.
