Rash and other nonspecific skin eruption (R21) ICD-10-CM
The R21 code range covers rash and other nonspecific skin eruption with 1 ICD-10-CM diagnosis codes. 1 of them are billable and valid for claim submission in fiscal year 2026, and the category headers group them but cannot themselves be billed.
Includes
This note appears immediately under a three character code title to further define, or give examples of, the content of the category.
- rash NOS
Type 1 Excludes
A type 1 excludes note is a pure excludes note. It means "NOT CODED HERE!" An Excludes1 note indicates that the code excluded should never be used at the same time as the code above the Excludes1 note. An Excludes1 is used when two conditions cannot occur together, such as a congenital form versus an acquired form of the same condition.
- specified type of rash- code to condition
- vesicular eruption R23.8
Codes in the R21 Range 1 codes · 1 billable
- R21 Rash and other nonspecific skin eruption
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the R21 range.
Orthostatic Intolerance
Symptoms of cerebral hypoperfusion or autonomic overaction which develop while the subject is standing, but are relieved on recumbency. Types of this include NEUROCARDIOGENIC SYNCOPE; POSTURAL ORTHOSTATIC TACHYCARDIA SYNDROME; and neurogenic ORTHOSTATIC HYPOTENSION. (From Noseworthy, JH., Neurological Therapeutics Principles and Practice, 2007, p2575-2576)
Postural Orthostatic Tachycardia Syndrome
A syndrome of ORTHOSTATIC INTOLERANCE combined with excessive upright TACHYCARDIA, and usually without associated ORTHOSTATIC HYPOTENSION. All variants have in common an excessively reduced venous return to the heart (central HYPOVOLEMIA) while upright.
About the R21 Code Range
ICD-10 code R21 is used to identify cases of rash and other nonspecific skin eruptions that do not have a more precise diagnosis. This code covers a broad range of skin signs and symptoms, making it applicable when a rash’s exact cause or classification is unclear.
The code R21 covers various symptoms such as maculopapular eruptions, papular or bullous eruptions, and other types of skin rashes including those described as "acute pustular," "erythematous," or "blanching." It also applies to rashes linked with conditions like human immunodeficiency virus (HIV) infection—sometimes called a "papular pruritic eruption"—and other less specific skin presentations like “butterfly rash” or “vaccination site rash.” When coders encounter terms like “skin rash with AIDS,” “erythematous rash,” or “rash of genitalia,” the ICD-10 code R21 helps ensure these symptoms are accurately documented. This broad code supports coding skin eruptions from various causes when a definitive diagnosis is not established, serving as a practical option for documenting diverse, nonspecific skin eruptions in medical records.
Questions About This Page
How many billable codes are in the R21 range?
Of the 1 codes in this range, 1 are billable and valid for claim submission from October 1, 2025 through September 30, 2026. Category header codes group them but cannot be reported on claims.
What does the R21 range classify?
The range classifies rash and other nonspecific skin eruption. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2026 ICD-10-CM Tabular List and order file, effective October 1, 2025 through September 30, 2026.
