2026 ICD-10-CM Diagnosis Code S30.821ABlister (nonthermal) of abdominal wall, initial encounter

ICD-10-CM Codes›S00–T88›S30-S39›S30

ICD-10-CM S30.821A
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

S30.821A is a billable ICD-10-CM diagnosis code for blister (nonthermal) of abdominal wall, 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

ICD-10-CM Code
S30.821A
Billable Status
Yes — Valid for Submission
Code Describes
Blister (nonthermal) of abdominal wall, initial encounter
Short Description
Blister (nonthermal) of abdominal wall, initial encounter
Same as the full description in the CMS dataset.
Parent Code
S30.821
Blister (nonthermal) of abdominal wall

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionS30-S39Injuries to the abdomen, lower back, lumbar spine, pelvis and external genitals
CategoryS30Superficial injury of abdomen, lower back, pelvis and external genitals
This CodeS30.821ABlister (nonthermal) of abdominal wall, initial encounter

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Blister of abdominal wall with infection
  • Blister of abdominal wall without infection
  • Blister of flank with infection
  • Blister of flank without infection
  • Blister of groin with infection
  • Blister of groin without infection
  • Superficial injury of flank with infection
  • Superficial injury of groin with infection
  • Traumatic blister of abdominal wall
  • Traumatic blister of abdominal wall, infected
  • Traumatic blister of flank
  • Traumatic blister of flank, infected
  • Traumatic blister of groin
  • Traumatic blister of groin, infected

Coding GuidelinesGuidance

The appropriate 7th character is to be added to each code from block Superficial injury of abdomen, lower back, pelvis and external genitals (S30). 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

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 S30.821A to ICD-9-CMHistory

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

ICD-9-CM
911.2 Blister trunk
Approximate The match is approximate rather than exact.

Code History & ChangesHistory

Replaced This code was replaced in the FY 2026 code set by:

  • S30.82AA - Blister (nonthermal) of flank, initial encounter
  • S30.82AA - Blister (nonthermal) of flank, initial encounter
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 S30.821AOverview

Is S30.821A (Blister (nonthermal) of abdominal wall) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report blister (nonthermal) of abdominal wall, initial encounter on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What does the 7th character A in S30.821A mean?

The final character A marks the initial encounter: use it while the patient is receiving active treatment for blister (nonthermal) of abdominal wall, such as an emergency visit or first evaluation.

What MS-DRG does S30.821A group to?

When blister (nonthermal) of abdominal wall, 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 S30.821A?

Under the General Equivalence Mappings, blister (nonthermal) of abdominal wall, initial encounter converts to ICD-9-CM 911.2 (blister trunk). 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.