2026 ICD-10-CM Diagnosis Code L85.9Epidermal thickening, unspecified

ICD-10-CM Codes›L00–L99›L80-L99›L85

ICD-10-CM L85.9
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

L85.9 is a billable ICD-10-CM diagnosis code for epidermal thickening, unspecified. 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 arthrogryposis hyperkeratosis syndrome lethal form. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified skin disorders.

Code Identity

ICD-10-CM Code
L85.9
Billable Status
Yes — Valid for Submission
Code Describes
Epidermal thickening, unspecified
Short Description
Epidermal thickening, unspecified
Same as the full description in the CMS dataset.
Parent Code
L85
Other epidermal thickening

Code Classification

ChapterL00–L99Diseases of the skin and subcutaneous tissue
SectionL80-L99Other disorders of the skin and subcutaneous tissue
CategoryL85Other epidermal thickening
This CodeL85.9Epidermal thickening, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Arthrogryposis hyperkeratosis syndrome lethal form
  • Epithelial hyperplasia of skin
  • Focal epithelial hyperplasia of skin
  • Hyperkeratosis of female perineum
  • Hyperkeratosis of nipple
  • Perforation of tympanic membrane with proliferation of keratinized epithelium from middle to external ear

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.

    • Hyperkeratosis
    • Hyperplasia, hyperplastic
      • epithelial
    • Hyperplasia, hyperplastic
      • epithelial
        • skin
    • Pachyderma, pachydermia
    • Thickening
      • epidermal

Clinical ClassificationClinical

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

CCSR SKN007
Other specified and unspecified skin disorders
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 L85.9 to ICD-9-CMHistory

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

ICD-9-CM
701.9 Skin hypertro/atroph NOS
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 L85.9Overview

Is L85.9 (Other epidermal thickening) a billable code?

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

What MS-DRG does L85.9 group to?

When epidermal thickening, unspecified 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 L85.9?

Under the General Equivalence Mappings, epidermal thickening, unspecified converts to ICD-9-CM 701.9 (skin hypertro/atroph NOS). The mapping is approximate, so confirm the match fits the documentation.

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.