2027 ICD-10-CM Diagnosis Code L21.9Seborrheic dermatitis, unspecified

ICD-10-CM Codes›L00–L99›L20-L30›L21

ICD-10-CM L21.9
CMSSource: CMS FY 2027 ICD-10-CM dataset · Effective Oct 1, 2026 – Sep 30, 2027

L21.9 is a billable ICD-10-CM diagnosis code for seborrheic dermatitis, 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. In AHRQ's Clinical Classifications Software (CCSR), this diagnosis falls under Other specified inflammatory condition of skin.

Code Identity

ICD-10-CM Code
L21.9
Billable Status
Yes — Valid for Submission
Code Describes
Seborrheic dermatitis, unspecified
Short Description
Seborrheic dermatitis, unspecified
Same as the full description in the CMS dataset.
Parent Code
L21
Seborrheic dermatitis

Code Classification

ChapterL00–L99Diseases of the skin and subcutaneous tissue
SectionL20-L30Dermatitis and eczema
CategoryL21Seborrheic dermatitis
This CodeL21.9Seborrheic dermatitis, unspecified

Approximate SynonymsGuidance

Alternate terms and clinical phrases that map to this code.

  • Acute seborrheic dermatitis
  • Chronic seborrheic dermatitis
  • Disorder of skin due to human immunodeficiency virus infection
  • Generalized seborrheic dermatitis
  • Genitocrural seborrheic dermatitis
  • Perianal dermatitis
  • Perianal seborrheic dermatitis
  • Seborrhea faciei
  • Seborrheic blepharitis
  • Seborrheic dermatitis
  • Seborrheic dermatitis due to human immunodeficiency virus infection
  • Seborrheic eczema-like eruption
  • Truncal seborrheic dermatitis

Instructional NotesGuidance

Instructions from the official ICD-10-CM Tabular List that apply to L21.9: its own notes plus those printed at L21, block L20-L30, 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.

  • Seborrhea NOS

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 L21 Seborrheic dermatitis applies to 4 codes
  • infective dermatitis (L30.3)
  • seborrheic keratosis (L82.-)
From Block L20-L30 Dermatitis and eczema applies to 74 codes
  • chronic (childhood) granulomatous disease (D71-)
  • dermatitis gangrenosa (L08.0)
  • dermatitis herpetiformis (L13.0)
  • dry skin dermatitis (L85.3)
  • factitial dermatitis (L98.1)
  • perioral dermatitis (L71.0)
  • radiation-related disorders of the skin and subcutaneous tissue (L55-L59)
  • stasis dermatitis (I87.2)
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.-)

Notes

General instructions on how these codes are used.

From Block L20-L30 Dermatitis and eczema applies to 74 codes
  • In this block the terms dermatitis and eczema are used synonymously and interchangeably.

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

Referenced in Other NotesGuidance

Instructional notes printed at other codes that name L21.9, its category, or a range that includes it.

Excludes2 1

These codes carry an Excludes2 note naming L21.9: its condition is not part of those codes, and both may be reported when the patient has both.

  • L82 Seborrheic keratosis
    seborrheic dermatitis (L21.-) names L21.-, which includes this code

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 SKN002
Other specified inflammatory condition of skin
Default principal diagnosis: inpatient Yes · outpatient Yes

Clinical InformationClinical

  • Dermatitis, Seborrheic

    a chronic inflammatory disease of the skin with unknown etiology. it is characterized by moderate erythema, dry, moist, or greasy (sebaceous gland) scaling and yellow crusted patches on various areas, especially the scalp, that exfoliate as dandruff. seborrheic dermatitis is common in children and adolescents with hiv infections.

Patient EducationClinical

Dandruff, Cradle Cap, and Other Scalp Conditions

Your scalp is the skin on the top of your head. Unless you have hair loss, hair grows on your scalp. Different skin problems can affect your scalp.

Read the full article at MedlinePlus

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

Convert L21.9 to ICD-9-CMHistory

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

ICD-9-CM
690.10 Sebrrheic dermatitis NOS
Approximate The match is approximate rather than exact.
ICD-9-CM
706.3 Seborrhea
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 L21.9Overview

What is the ICD-10 code for seborrheic dermatitis, unspecified?

The ICD-10-CM code for seborrheic dermatitis, unspecified is L21.9 (sometimes written as L219). It is billable on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

Is L21.9 (Seborrheic dermatitis) a billable code?

Yes. This is a billable ICD-10-CM code, specific enough to report seborrheic dermatitis, unspecified on HIPAA-covered claims from October 1, 2026 through September 30, 2027.

What MS-DRG does L21.9 group to?

When seborrheic dermatitis, 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 L21.9?

Under the General Equivalence Mappings, seborrheic dermatitis, unspecified converts to ICD-9-CM 690.10 (sebrrheic dermatitis NOS) and 706.3 (seborrhea). The mapping is approximate, so confirm the match fits the documentation.