R50.81 Fever presenting with conditions classified elsewhere

Coding notes

From the ICD-10-CM FY2027 (effective October 1, 2026) tabular list. Notes on a parent code or category apply here too.

Excludes1

Not coded together with this code. The exception is when the two conditions are unrelated to each other.

• 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)

Code first

Code the underlying condition first, then this code.

• underlying condition when associated fever is present, such as with:
• leukemia (C91-C95)
• neutropenia (D70.-)
• sickle-cell disease (D57.-)