ICD-10-CM > R00-R99 > R50-R69 > R50 > R50.8 > R50.81 R50.81 Fever presenting with conditions classified elsewhere Billable/Specific Copy Code Copy Description Code First underlying condition when associated fever is present, such as with:leukemia (C91-C95)neutropenia (D70.-)sickle-cell disease (D57.-)