ICD-10-CM 2027 diagnosis code

L21Seborrheic dermatitis

Not billable — use a more specific code

L21 is a header code, so it can't be reported by itself. Choose one of the 4 more specific codes beneath it.

Code unchanged since ICD-10-CM took effect on October 1, 2015. Source: official FY2027 ICD-10-CM release from CDC/NCHS and CMS. Page updated September 29, 2026. About our data

About L21

L21 is the ICD-10-CM diagnosis code for seborrheic dermatitis. It belongs to block L20-L30 (dermatitis and eczema) and chapter 12 (diseases of the skin and subcutaneous tissue). It is a header code, so it can't be reported by itself; one of its 4 subcodes must be used instead.

To report this condition, pick the subcode that matches the documentation: L21.0 (capitis), L21.1 (dermatitis), L21.8 (dermatitis) and L21.9 (unspecified).

The conditions in its Excludes2 note aren't part of L21, but may be coded alongside it if the patient has both: infective dermatitis (L30.3) and seborrheic keratosis (L82.-).

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Specific codes under L21

Coding notes

Excludes2Not included here — may be reported together if both conditions exist

infective dermatitis (L30.3)
seborrheic keratosis (L82.-)

Notes that apply from higher levels

Instructions written at a parent level also apply to L21.

Broader instructions also apply from L20-L30 Dermatitis and eczema and Chapter 12: Diseases of the skin and subcutaneous tissue.

Codes whose notes reference L21

L82Excludes2

Code history

2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027

FY2016 (effective 10/1/2015): Added (first year of ICD-10-CM)
No changes since FY2016.

Common questions about L21

Is L21 billable?: No. L21 is a header code. Report one of its more specific subcodes instead.