ICD-10-CM · Chapter 18 · R00-R99
R50 Fever of other and unknown origin
Excludes 1 (cannot be coded together)
- chills without fever (R68.83)
- febrile convulsions (R56.0-)
- fever of unknown origin during labor (O75.2)
- fever of unknown origin in newborn (P81.9)
- hypothermia due to illness (R68.0)
- malignant hyperthermia due to anesthesia (T88.3)
- puerperal pyrexia NOS (O86.4)
Subcodes
Subcodes are listed below for reference. Detail pages are not available for chapters 11–22.
| Code | Description | Billable |
|---|---|---|
| R50..2 | Drug induced fever | Yes |
| R50..8 | Other specified fever | No |
| R50..81 | Fever presenting with conditions classified elsewhere | Yes |
| R50..82 | Postprocedural fever | Yes |
| R50..83 | Postvaccination fever | Yes |
| R50..84 | Febrile nonhemolytic transfusion reaction | Yes |
| R50..9 | Fever, unspecified | Yes |
Plain-language term for this code
The following entry in the US Medical Glossary corresponds to ICD-10-CM category R50:
- Fever — Fiebre
Last reviewed: September 2026