2026 ICD-10-CM Diagnosis Code L72.12Trichodermal cyst

ICD-10-CM Codes›L00–L99›L60-L75›L72

ICD-10-CM L72.12
CMSSource: CMS FY 2026 ICD-10-CM dataset · Effective Oct 1, 2025 – Sep 30, 2026

L72.12 is a billable ICD-10-CM diagnosis code for trichodermal cyst. 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 congenital leukonychia. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified and unspecified skin disorders.

Code Identity

ICD-10-CM Code
L72.12
Billable Status
Yes — Valid for Submission
Code Describes
Trichodermal cyst
Short Description
Trichodermal cyst
Same as the full description in the CMS dataset.
Parent Code
L72.1
Pilar and trichodermal cyst

Code Classification

ChapterL00–L99Diseases of the skin and subcutaneous tissue
SectionL60-L75Disorders of skin appendages
CategoryL72Follicular cysts of skin and subcutaneous tissue
This CodeL72.12Trichodermal cyst

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Congenital leukonychia
  • FLOTCH syndrome
  • Leukonychia totalis
  • Neoplasm of uncertain behavior of skin of scalp
  • Proliferating pilar cyst
  • Proliferating trichilemmal cyst of scalp
  • Trichilemmal cyst

Tabular List NotesGuidance

Coding notes and annotation back-references applicable to this code.

Inclusion Terms

  • Trichilemmal (proliferating) cyst

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.

    • Cyst(colloid) (mucous) (simple) (retention)
      • trichilemmal (proliferating)
    • Cyst(colloid) (mucous) (simple) (retention)
      • trichodermal

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 L72.12 to ICD-9-CMHistory

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

ICD-9-CM
704.42 Trichilemmal cyst
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 L72.12Overview

Is L72.12 (Pilar and trichodermal cyst) a billable code?

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

What MS-DRG does L72.12 group to?

When trichodermal cyst 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 L72.12?

Under the General Equivalence Mappings, trichodermal cyst converts to ICD-9-CM 704.42 (trichilemmal cyst). 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.