2026 ICD-10-CM Diagnosis Code L59.0Erythema ab igne [dermatitis ab igne]

ICD-10-CM Codes›L00–L99›L55-L59›L59

ICD-10-CM L59.0
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

L59.0 is a billable ICD-10-CM diagnosis code for erythema ab igne [dermatitis ab igne]. 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. Coders also document this condition as erythema ab igne. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Contact dermatitis.

Code Identity

ICD-10-CM Code
L59.0
Billable Status
Yes — Valid for Submission
Code Describes
Erythema ab igne [dermatitis ab igne]
Short Description
Erythema ab igne [dermatitis ab igne]
Same as the full description in the CMS dataset.
Parent Code
L59
Other disorders of skin and subcutaneous tissue related to radiation

Code Classification

ChapterL00–L99Diseases of the skin and subcutaneous tissue
SectionL55-L59Radiation-related disorders of the skin and subcutaneous tissue
CategoryL59Other disorders of skin and subcutaneous tissue related to radiation
This CodeL59.0Erythema ab igne [dermatitis ab igne]

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Erythema ab igne
  • Heat-induced dermatosis

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.

    • Dermatitis(eczematous)
      • ab igne
    • Dermatitis(eczematous)
      • calorica
    • Dermatitis(eczematous)
      • combustionis
    • Dermatitis(eczematous)
      • due to
        • hot
          • weather or places
    • Dermatitis(eczematous)
      • heat
    • Erythema, erythematous(infectional) (inflammation)
      • ab igne
    • Heat(effects)
      • dermatitis or eczema

Clinical ClassificationClinical

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

CCSR SKN005
Contact dermatitis
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Erythema Ab Igne

    a cutaneous finding caused by prolonged heat exposure (e.g., space heater) and local heat injury (e.g., caused by laser therapy). it is characterized by epidermal atrophy, reticular hyperpigmentation, and telangiectatic dermatosis.

  • Laser Therapy

    the use of photothermal effects of lasers to coagulate, incise, vaporize, resect, dissect, or resurface tissue.

Patient EducationClinical

Radiation Exposure

Radiation is energy. It travels in the form of energy waves or high-speed particles. Radiation can occur naturally or be man-made. There are two types:

The full article covers:

  • What is radiation?
  • What are the sources of radiation exposure?
  • What are the health effects of radiation exposure?
  • What are the treatments for acute radiation sickness?
  • How can radiation exposure be prevented?

Read the full article at MedlinePlus

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

Convert L59.0 to ICD-9-CMHistory

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

ICD-9-CM
692.82 Dermatitis oth radiation
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 L59.0Overview

Is L59.0 a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report erythema ab igne [dermatitis ab igne] on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does L59.0 group to?

When erythema ab igne [dermatitis ab igne] is the principal diagnosis on an inpatient stay, it groups to MS-DRG 606, 607, with relative weights from 0.9064 to 1.5132 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of L59.0?

Under the General Equivalence Mappings, erythema ab igne [dermatitis ab igne] converts to ICD-9-CM 692.82 (dermatitis oth radiation). 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.