Fever of other and unknown origin (R50) ICD-10-CM
The R50 code range covers fever of other and unknown origin with 8 ICD-10-CM diagnosis codes. 6 of them are billable and valid for claim submission in fiscal year 2027, and the category headers group them but cannot themselves be billed.
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.
Codes in the R50 Range 8 codes · 6 billable
- R50 Fever of other and unknown originNon-billable
- R50.2 Drug induced fever
- R50.8 Other specified feverNon-billable
- R50.81 Fever presenting with conditions classified elsewhere
- R50.82 Postprocedural fever
- R50.83 Postvaccination fever
- R50.84 Febrile nonhemolytic transfusion reaction
- R50.9 Fever, unspecified
Clinical Terms in This Code Range
Definitions from the National Library of Medicine for conditions coded in the R50 range.
Drug Fever
Drug-induced fever.
Fever
An abnormal elevation of body temperature, usually as a result of a pathologic process.
About the R50 Code Range
Fever may have an unknown origin or appear with another condition, after a procedure, or after vaccination.
R50 separates fevers by their stated context. R50.2 describes drug-induced fever, and R50.81 describes fever presenting with a condition classified elsewhere. R50.82 identifies postprocedural fever, R50.83 postvaccination fever, and R50.84 a febrile nonhemolytic transfusion reaction. R50.8 describes other specified fever; R50.9 describes unspecified fever.
Questions About This Page
How many billable codes are in the R50 range?
Of the 8 codes in this range, 6 are billable and valid for claim submission from October 1, 2026 through September 30, 2027. Category header codes group them but cannot be reported on claims.
What does the R50 range classify?
The range classifies fever of other and unknown origin. Each code links to its own reference page with billing status, MS-DRG grouping, coding notes, and clinical information.
Related References
Source: CMS FY 2027 ICD-10-CM Tabular List and order file, effective October 1, 2026 through September 30, 2027.
