2026 ICD-10-CM Diagnosis Code L20.84Intrinsic (allergic) eczema

ICD-10-CM Codes›L00–L99›L20-L30›L20

ICD-10-CM L20.84
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

L20.84 is a billable ICD-10-CM diagnosis code for intrinsic (allergic) eczema. 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Allergic reactions and Other specified inflammatory condition of skin.

Code Identity

ICD-10-CM Code
L20.84
Billable Status
Yes — Valid for Submission
Code Describes
Intrinsic (allergic) eczema
Short Description
Intrinsic (allergic) eczema
Same as the full description in the CMS dataset.
Parent Code
L20.8
Other atopic dermatitis

Code Classification

ChapterL00–L99Diseases of the skin and subcutaneous tissue
SectionL20-L30Dermatitis and eczema
CategoryL20Atopic dermatitis
This CodeL20.84Intrinsic (allergic) eczema

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.

    • Eczema(acute) (chronic) (erythematous) (fissum) (rubrum) (squamous)
      • intrinsic (allergic)

Clinical ClassificationClinical

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

CCSR INJ031
Allergic reactions
Default principal diagnosis: inpatient No · outpatient No
CCSR SKN002
Other specified inflammatory condition of skin
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Atopic Dermatitis

    a common form of eczema that is characterized by chronic skin inflammation, dryness, pruritus, and irritation. it often presents in patients with allergies and may more commonly be noted on the folds of the skin or the scalp.

  • FAF2 wt Allele|ETEA|Expressed In T Cells and Eosinophils In Atopic Dermatitis 2 Gene|Expressed In T-Cells and Eosinophils In Atopic Dermatitis Gene|FAF Family, Member 2 Gene|Fas Associated Factor Family Member 2 wt Allele|Fas-Associated Factor Family, Member 2 Gene|KIAA0887|UBXD8|UBXN3B

    human faf2 wild-type allele is located in the vicinity of 5q35.2 and is approximately 62 kb in length. this allele, which encodes fas-associated factor 2 protein, plays a role in endoplasmic reticulum-associated degradation of misfolded proteins and the regulation of apoptosis. aberrant overexpression of the gene is associated with atopic dermatitis.

  • Immunodeficiency 11B with Atopic Dermatitis|Atopic Dermatitis, Elevated IgE, and Eosinophilia|CARD11/CID|IMD11B

    an autosomal dominant condition caused by mutation(s) in the card11 gene, encoding caspase recruitment domain-containing protein 11. it is characterized by the onset of moderate to severe atopic dermatitis in early childhood, defects in t-cell activation, increased ige, and eosinophilia.

Patient EducationClinical

Eczema

Eczema is a term for several different types of skin swelling. Eczema is also called dermatitis. Most types cause dry, itchy skin and rashes on the face, inside the elbows and behind the knees, and on the hands and feet. Scratching the skin can cause it to turn red, and to swell and itch even more.

Read the full article at MedlinePlus

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

Convert L20.84 to ICD-9-CMHistory

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

ICD-9-CM
691.8 Other atopic dermatitis
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 L20.84Overview

Is L20.84 (Other atopic dermatitis) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report intrinsic (allergic) eczema on HIPAA-covered claims from October 1, 2025 through September 30, 2026.

What MS-DRG does L20.84 group to?

When intrinsic (allergic) eczema 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 L20.84?

Under the General Equivalence Mappings, intrinsic (allergic) eczema converts to ICD-9-CM 691.8 (other atopic dermatitis). The mapping is approximate, so confirm the match fits the documentation.

Footnotes

[1] Chronic - a chronic condition code indicates a condition lasting 12 months or longer and its effect on the patient based on one or both of the following criteria:

  • The condition results in the need for ongoing intervention with medical products,treatment, services, and special equipment
  • The condition places limitations on self-care, independent living, and social interactions.