2026 ICD-10-CM Diagnosis Code T32.91Corrosions involving 90% or more of body surface with 10-19% third degree corrosion

ICD-10-CM Codes›S00–T88›T30-T32›T32

ICD-10-CM T32.91
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

T32.91 is a billable ICD-10-CM diagnosis code for corrosions involving 90% or more of body surface with 10-19% third degree corrosion. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026). In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Burn and corrosion, initial encounter.

Code Identity

ICD-10-CM Code
T32.91
Billable Status
Yes — Valid for Submission
Code Describes
Corrosions involving 90% or more of body surface with 10-19% third degree corrosion
Short Description
Corros 90%/more of body surface w 10-19% third degree corros
Parent Code
T32.9
Corrosions involving 90% or more of body surface

Code Classification

ChapterS00–T88Injury, poisoning and certain other consequences of external causes
SectionT30-T32Burns and corrosions of multiple and unspecified body regions
CategoryT32Corrosions classified according to extent of body surface involved
This CodeT32.91Corrosions involving 90% or more of body surface with 10-19% third degree corrosion

Coding GuidelinesGuidance

The ICD-10-CM makes a distinction between burns and corrosions. The burn codes are for thermal burns, except sunburns, that come from a heat source, such as a fire or hot appliance. The burn codes are also for burns resulting from electricity and radiation. Corrosions are burns due to chemicals. The guidelines are the same for burns and corrosions.

Sequence first the code that reflects the highest degree of burn when more than one burn is present.

  • When the reason for the admission or encounter is for treatment of external multiple burns, sequence first the code that reflects the burn of the highest degree.
  • When a patient has both internal and external burns, the circumstances of admission govern the selection of the principal diagnosis or first-listed diagnosis.
  • When a patient is admitted for burn injuries and other related conditions such as smoke inhalation and/or respiratory failure, the circumstances of admission govern the selection of the principal or first-listed diagnosis.

Assign codes from category T31, Burns classified according to extent of body surface involved, or T32, Corrosions classified according to extent of body surface involved, when the site of the burn is not specified or when there is a need for additional data. It is advisable to use category T31 as additional coding when needed to provide data for evaluating burn mortality, such as that needed by burn units. It is also advisable to use category T31 as an additional code for reporting purposes when there is mention of a third-degree burn involving 20 percent or more of the body surface.

Categories T31 and T32 are based on the classic "rule of nines" in estimating body surface involved: head and neck are assigned nine percent, each arm nine percent, each leg 18 percent, the anterior trunk 18 percent, posterior trunk 18 percent, and genitalia one percent. Providers may change these percentage assignments where necessary to accommodate infants and children who have proportionately larger heads than adults, and patients who have large buttocks, thighs, or abdomen that involve burns.

Source: ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026, published by CMS and the National Center for Health Statistics.

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

External Cause of Injuries IndexGuidance

References for this code in the External Cause of Injuries Index.

    • Corrosion(injury) (acid) (caustic) (chemical) (lime) (external) (internal)
      • extent (percentage of body surface)
        • 90 percent or more (0-9 percent third degree)
          • with
            • 10-19 percent third degree
    • Corrosion(injury) (acid) (caustic) (chemical) (lime) (external) (internal)
      • unspecified site with extent of body surface involved specified
        • 90 percent or more (0-9 percent third degree)
          • with
            • 10-19 percent third degree

Clinical ClassificationClinical

AHRQ’s CCSR groups this code into broader clinical categories.

CCSR INJ019
Burn and corrosion, initial encounter
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Burns

A burn is damage to your body's tissues caused by heat, chemicals, electricity, sunlight, or radiation. Scalds from hot liquids and steam, building fires and flammable liquids and gases are the most common causes of burns. Another kind is an inhalation injury, caused by breathing smoke.

Read the full article at MedlinePlus

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

Convert T32.91 to ICD-9-CMHistory

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

ICD-9-CM
948.91 90% + bdy brn/10-19% 3rd
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 T32.91Overview

Is T32.91 (Corrosions involving 90% or more of body surface) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report corrosions involving 90% or more of body surface with 10-19% third degree corrosion on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What is the ICD-9 equivalent of T32.91?

Under the General Equivalence Mappings, corrosions involving 90% or more of body surface with 10-19% third degree corrosion converts to ICD-9-CM 948.91 (90% + bdy brn/10-19% 3rd). 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.