ICD-10 code for epidemic disease

The ICD-10-CM code for epidemic disease is B99.9 (Unspecified infectious disease). The official index lists 1 more specific code, so check the documentation for details such as type, cause, site or severity before settling on B99.9.

Within B99, choose B99.9 (Unspecified infectious disease) only when documentation doesn't support a more specific option: other infectious disease (B99.8).

It is not a CC or MCC, so as a secondary diagnosis it doesn't change the MS-DRG severity level.

In MS-DRG v44.0, it is part of the grouping logic for DRG 867 (Other Infectious and Parasitic Diseases Diagnoses with MCC, relative weight 2.1859), DRG 868 (Other Infectious and Parasitic Diseases Diagnoses with CC, relative weight 1.0235) and DRG 869 (Other Infectious and Parasitic Diseases Diagnoses without CC/MCC, relative weight 0.6787), in 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.