R21 — Rash and other nonspecific skin eruption

R21

ICD-10 Chapter 18: Symptoms, Signs & Abnormal Findings — illustrative image — Chapter 18: Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00–R99) — illustrative image

What this code means

A rash is a change in the skin's appearance or texture; this code is for a nonspecific skin eruption while the cause is assessed.

Also called: rash, skin eruption.

When this code is used

Used for rash and other nonspecific skin eruption.

Where it sits in ICD-10-CM

Code R21 belongs to Chapter 18: Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified, which covers codes R00–R99 in the FY2027 ICD-10-CM tabular list. The official description above is copied verbatim from the CDC/NCHS FY2027 code file.

Related symptoms

Rash

Related anatomy

Skin

Frequently asked questions

What is ICD-10-CM code R21?

R21 is the ICD-10-CM diagnosis code for “Rash and other nonspecific skin eruption”. A rash is a change in the skin's appearance or texture; this code is for a nonspecific skin eruption while the cause is assessed.

When is code R21 used?

Used for rash and other nonspecific skin eruption. It belongs to Chapter 18 of ICD-10-CM (Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified).

This guide explains ICD-10-CM codes in plain language for patients, students and other readers. It is educational information only — not coding, billing or medical advice. The code recorded for any real encounter is assigned from the full clinical documentation by the treating team and qualified coders, and only they can decide which code fits a specific case.