2027 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 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

L85.9 is a billable ICD-10-CM diagnosis code for epidermal thickening, unspecified. It is valid on HIPAA claims for fiscal year 2027 (October 1, 2026 through September 30, 2027) 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 due to lymphedema
  • Hyperkeratosis of female perineum
  • Hyperkeratosis of nipple
  • Perforation of tympanic membrane with proliferation of keratinized epithelium from middle to external ear

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to L85.9: its own notes plus those printed at L85 and Chapter 12. A note printed at a category, block or chapter applies to every code under it.

Excludes2

Not included here: the excluded condition is not part of this code, but a patient may have both, so both codes may be reported.

From L85 Other epidermal thickening applies to 6 codes
  • hypertrophic disorders of the skin (L91.-)
From Chapter 12 (L00-L99) Diseases of the skin and subcutaneous tissue applies to 1,001 codes
  • certain conditions originating in the perinatal period (P04-P96)
  • certain infectious and parasitic diseases (A00-B99)
  • complications of pregnancy, childbirth and the puerperium (O00-O9A)
  • congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
  • endocrine, nutritional and metabolic diseases (E00-E88)
  • lipomelanotic reticulosis (I89.8)
  • neoplasms (C00-D49)
  • symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)
  • systemic connective tissue disorders (M30-M36)
  • viral warts (B07.-)

Source: CMS ICD-10-CM Tabular List. How to read instructional notes.

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name L85.9, its category, or a range that includes it.

Excludes1 1

These codes carry an Excludes1 note naming L85.9: they are not reported together with it, unless the two conditions are unrelated.

  • R23.4 Changes in skin texture
    epidermal thickening NOS (L85.9)

Index to Diseases and InjuriesGuidance

Alphabetical index entries that point to this code.

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 2017–2026No changes
FY 2027CurrentCurrent code set, no changesEffective October 1, 2026 through September 30, 2027.

Questions About L85.9Overview

What is the ICD-10 code for epidermal thickening, unspecified?

The ICD-10-CM code for epidermal thickening, unspecified is L85.9 (sometimes written as L859). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

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 607, 606, with relative weights from 0.8772 to 1.5721 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.