2026 ICD-10-CM Diagnosis Code L13.1Subcorneal pustular dermatitis

ICD-10-CM Codes›L00–L99›L10-L14›L13

ICD-10-CM L13.1
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

L13.1 is a billable ICD-10-CM diagnosis code for subcorneal pustular dermatitis. 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 monoclonal gammopathy of uncertain significance. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified inflammatory condition of skin.

Code Identity

ICD-10-CM Code
L13.1
Billable Status
Yes — Valid for Submission
Code Describes
Subcorneal pustular dermatitis
Short Description
Subcorneal pustular dermatitis
Same as the full description in the CMS dataset.
Parent Code
L13
Other bullous disorders

Code Classification

ChapterL00–L99Diseases of the skin and subcutaneous tissue
SectionL10-L14Bullous disorders
CategoryL13Other bullous disorders
This CodeL13.1Subcorneal pustular dermatitis

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Monoclonal gammopathy of uncertain significance
  • Subcorneal pustular dermatosis
  • Subcorneal pustular dermatosis with paraproteinemia

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Sneddon-Wilkinson disease

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)
      • pustular
        • subcorneal
    • Dermatosis
      • pustular, subcorneal
    • Disease, diseased
      • Sneddon-Wilkinson (subcorneal pustular dermatosis)
    • Disease, diseased
      • Wilkinson-Sneddon (subcorneal pustular dermatosis)
    • Sneddon-Wilkinson disease or syndrome(sub-corneal pustular dermatosis)
    • Syndrome
      • Sneddon-Wilkinson
    • Syndrome
      • Wilkinson-Sneddon
    • Wilkinson-Sneddon disease or syndrome

Clinical ClassificationClinical

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

CCSR SKN002
Other specified inflammatory condition of skin
Default principal diagnosis: inpatient Yes · outpatient Yes

Patient EducationClinical

Skin Conditions

Your skin is your body's largest organ. It covers the entire outside of your body. There are many ways that your skin protects your body and helps keep you healthy. For example, it:

The full article covers:

  • What does your skin do?
  • What problems and conditions can affect your skin?
  • How can I keep my skin healthy?

Read the full article at MedlinePlus

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

Convert L13.1 to ICD-9-CMHistory

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

ICD-9-CM
694.1 Subcorneal pust dermatos
Exact Match The mapping is direct, with no qualifiers.

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 L13.1Overview

Is L13.1 (Other bullous disorders) a billable code?

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

What MS-DRG does L13.1 group to?

When subcorneal pustular dermatitis 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 L13.1?

Under the General Equivalence Mappings, subcorneal pustular dermatitis converts to ICD-9-CM 694.1 (subcorneal pust dermatos). The mapping is a direct match.

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.