2026 ICD-10-CM Diagnosis Code L13.9Bullous disorder, unspecified

ICD-10-CM Codes›L00–L99›L10-L14›L13

ICD-10-CM L13.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

L13.9 is a billable ICD-10-CM diagnosis code for bullous disorder, unspecified. It is valid on HIPAA claims for fiscal year 2026 (October 1, 2025 through September 30, 2026) and groups to MS-DRG 595 through 596. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified inflammatory condition of skin.

Code Identity

ICD-10-CM Code
L13.9
Billable Status
Yes — Valid for Submission
Code Describes
Bullous disorder, unspecified
Short Description
Bullous disorder, unspecified
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 CodeL13.9Bullous disorder, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Bullous dermatosis
  • Bullous eruption
  • Bullous eruption of hand
  • Bullous eruption of pharynx
  • Bullous insect bite reaction
  • Bullous wheal
  • Insect bite reaction
  • Intraepidermal bullous dermatosis
  • Nail dystrophy associated with bullous dermatoses
  • Neonatal bullous dermatosis caused by maternal antibodies
  • Neonatal sucking blisters
  • Wheal

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)
      • bullous, bullosa
    • Dermatosis
      • bullous
    • Disease, diseased
      • bullous

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 L13.9 to ICD-9-CMHistory

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

ICD-9-CM
694.9 Bullous dermatoses NOS
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 L13.9Overview

Is L13.9 (Other bullous disorders) a billable code?

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

What MS-DRG does L13.9 group to?

When bullous disorder, unspecified is the principal diagnosis on an inpatient stay, it groups to MS-DRG 595, 596, with relative weights from 1.0825 to 2.1207 depending on complications. Higher weights mean higher Medicare reimbursement.

What is the ICD-9 equivalent of L13.9?

Under the General Equivalence Mappings, bullous disorder, unspecified converts to ICD-9-CM 694.9 (bullous dermatoses NOS). 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.