R21

ICD-10Billable

Rash and other nonspecific skin eruption

Official ICD-10-CM descriptor (FY2026)

Rash and other nonspecific skin eruption

R21 is valid for submission on a claim — CMS flags it as a billable, specific code.

Includes

rash NOS

Excludes1

Not coded here. An Excludes1 code should never be reported at the same time as the code above it.

specified type of rash- code to condition
vesicular eruption (R23.8)

Where this code sits

Chapter: 18. Symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R99)
Block: Symptoms and signs involving the skin and subcutaneous tissue (R20-R23)

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Source

ICD-10-CM FY2026. Centers for Medicare & Medicaid Services (CMS) / National Center for Health Statistics (NCHS), “2026 ICD-10-CM Code Descriptions in Tabular Order” (icd10cm_order_2026.txt). Download the original file from cms.gov. Public domain (US Government work). Descriptors, billable flags and instructional notes on this page are reproduced from that file without modification. Krasyn adds no clinical guidance.