ICD-10 code for atypical mycobacterium

The ICD-10-CM code for atypical mycobacterium is A31.9 (Mycobacterial infection, unspecified). The official index lists 3 more specific codes, so check the documentation for details such as type, cause, site or severity before settling on A31.9.

Within A31, choose A31.9 (Mycobacterial infection, unspecified) only when documentation doesn't support a more specific option: pulmonary mycobacterial infection (A31.0), cutaneous mycobacterial infection (A31.1), disseminated mycobacterium avium-intracellulare complex (DMAC) (A31.2) and other mycobacterial infections (A31.8).

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 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), DRG 869 (Other Infectious and Parasitic Diseases Diagnoses without CC/MCC, relative weight 0.6787), DRG 974 (HIV with Major Related Condition with MCC, relative weight 3.0506), DRG 975 (HIV with Major Related Condition with CC, relative weight 1.3252) and DRG 976 (HIV with Major Related Condition without CC/MCC, relative weight 0.8124), in MDC 18 (Infectious and Parasitic Diseases, Systemic or Unspecified Sites) and MDC 25 (Human Immunodeficiency Virus Infections), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.