2026 ICD-10-CM Diagnosis Code L42Pityriasis rosea

ICD-10-CM Codes›L00–L99›L40-L45›L42

ICD-10-CM L42
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

L42 is a billable ICD-10-CM diagnosis code for pityriasis rosea. 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 Other specified inflammatory condition of skin.

Code Identity

ICD-10-CM Code
L42
Billable Status
Yes — Valid for Submission
Code Describes
Pityriasis rosea
Chapter
L40-L45
Papulosquamous disorders

Code Classification

ChapterL00–L99Diseases of the skin and subcutaneous tissue
SectionL40-L45Papulosquamous disorders
CategoryL42Pityriasis rosea
This CodeL42Pityriasis rosea

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Pityriasis rosea
  • Pityriasis rosea-like drug eruption

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.

    • Disease, diseased
      • Gibert's (pityriasis rosea)
    • Disease, diseased
      • Hebra's
        • pityriasis
          • maculata et circinata
    • Gibert's disease or pityriasis
    • Pityriasis(capitis)
      • circinata (et maculata)
    • Pityriasis(capitis)
      • rosea

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

Clinical InformationClinical

  • Pityriasis Rosea

    a mild exanthematous inflammation of unknown etiology. it is characterized by the presence of salmon-colored maculopapular lesions. the most striking feature is the arrangement of the lesions such that the long axis is parallel to the lines of cleavage. the eruptions are usually generalized, affecting chiefly the trunk, and the course is often self-limiting.

  • Pityriasis Rosea

    a mild, self-limited skin disorder that is most commonly seen in children and young adults. it is characterized by an initial large round spot on the chest, abdomen, or back, often referred to as a herald patch, that is usually followed within a week by a distinctive pattern of similar but smaller papules on the torso, arms, and legs. there may also be itching, especially when overheated.

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 L42 to ICD-9-CMHistory

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

ICD-9-CM
696.3 Pityriasis rosea
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 L42Overview

Is L42 (Pityriasis rosea) a billable code?

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

What MS-DRG does L42 group to?

When pityriasis rosea 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 L42?

Under the General Equivalence Mappings, pityriasis rosea converts to ICD-9-CM 696.3 (pityriasis rosea). 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.