ICD-10 code for varicella infection

The ICD-10-CM code for varicella infection is B01.9 (Varicella without complication).

Within B01, choose B01.9 (without complication) only when documentation doesn't support a more specific option: meningitis (B01.0), encephalitis, myelitis and encephalomyelitis (B01.1), pneumonia (B01.2) and with other complications (B01.8).

As a secondary diagnosis it is a CC (complication or comorbidity), which can move an inpatient stay into the "with CC" MS-DRG of its family, unless the principal diagnosis excludes it.

In MS-DRG v44.0, it is part of the grouping logic for DRG 791 (Prematurity with Major Problems, relative weight 4.1075), DRG 793 (Full Term Neonate with Major Problems, relative weight 4.2195), DRG 865 (Viral Illness with MCC, relative weight 1.3485) and DRG 866 (Viral Illness without MCC, relative weight 0.8692), in MDC 15 (Newborns and Other Neonates with Conditions Originating in the Perinatal Period) and MDC 18 (Infectious and Parasitic Diseases, Systemic or Unspecified Sites), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.