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

L72.12 is a billable ICD-10-CM diagnosis code for trichodermal cyst. 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 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

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to L72.12: its own notes plus those printed at block L60-L75 and Chapter 12. A note printed at a category, block or chapter applies to every code under it.

Applicable To

Conditions this code is used for: synonyms of the title or, for "other specified" codes, the conditions assigned to it. The list is not exhaustive.

  • Trichilemmal (proliferating) cyst

Excludes1

Not coded here: the excluded code is never reported together with this one, unless the two conditions are unrelated.

From Block L60-L75 Disorders of skin appendages applies to 85 codes
  • congenital malformations of integument (Q84.-)

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 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 L72.12, its category, or a range that includes it.

Excludes2 1

These codes carry an Excludes2 note naming L72.12: its condition is not part of those codes, and both may be reported when the patient has both.

  • L72.3 Sebaceous cyst
    trichilemmal (proliferating) cyst (L72.12)

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

Questions About L72.12Overview

What is the ICD-10 code for trichodermal cyst?

The ICD-10-CM code for trichodermal cyst is L72.12 (sometimes written as L7212). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

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, 2026 through September 30, 2027.

What MS-DRG does L72.12 group to?

When trichodermal cyst 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.

Can L72.12 be reported with a code from Q84?

Not as a rule. The Excludes1 note at block L60-L75, which applies to L72.12, lists "congenital malformations of integument (Q84.-)". An Excludes1 note means the excluded code is never reported together with this one; the only exception is when the two conditions are unrelated to each other (Official Guidelines, Section I.A.12.a).

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.