2026 ICD-10-CM Diagnosis Code L27.9Dermatitis due to unspecified substance taken internally

ICD-10-CM Codes›L00–L99›L20-L30›L27

ICD-10-CM L27.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

L27.9 is a billable ICD-10-CM diagnosis code for dermatitis due to unspecified substance taken internally. 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 baboon syndrome. 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
L27.9
Billable Status
Yes — Valid for Submission
Code Describes
Dermatitis due to unspecified substance taken internally
Short Description
Dermatitis due to unspecified substance taken internally
Same as the full description in the CMS dataset.
Parent Code
L27
Dermatitis due to substances taken internally

Code Classification

ChapterL00–L99Diseases of the skin and subcutaneous tissue
SectionL20-L30Dermatitis and eczema
CategoryL27Dermatitis due to substances taken internally
This CodeL27.9Dermatitis due to unspecified substance taken internally

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Baboon syndrome
  • Dermatitis caused by substance taken via oral route
  • Intertrigo
  • Localized dermatitis caused by substance taken via oral route

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)
      • due to
        • ingestion, ingested substance
    • Dermatitis(eczematous)
      • due to
        • internal agent

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

  • Intertrigo

    a superficial dermatitis occurring on skin surfaces in contact with each other, such as the axillae, neck creases, intergluteal fold, between the toes, etc. obesity is a predisposing factor. the condition is caused by moisture and friction and is characterized by erythema, maceration, burning, and exudation.

Patient EducationClinical

Rashes

A rash is an area of irritated or swollen skin. Many rashes are itchy, red, painful, and irritated. Some rashes can also lead to blisters or patches of raw skin. Rashes are a symptom of many different medical problems. Other causes include irritating substances and allergies. Certain genes can make people more likely to get rashes.

Read the full article at MedlinePlus

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

Convert L27.9 to ICD-9-CMHistory

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

ICD-9-CM
693.9 Dermat d/t int agent 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 L27.9Overview

Is L27.9 (Dermatitis due to substances taken internally) a billable code?

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

What MS-DRG does L27.9 group to?

When dermatitis due to unspecified substance taken internally 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 L27.9?

Under the General Equivalence Mappings, dermatitis due to unspecified substance taken internally converts to ICD-9-CM 693.9 (dermat d/t int agent NOS). The mapping is a direct match.

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.