ICD-10 code for Legionellosis

The ICD-10-CM code for Legionellosis is A48.1 (Legionnaires' 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 A48.1.

Within A48 (other bacterial diseases, not elsewhere classified), A48.1 is specifically for Legionnaires' disease. Related codes cover gas gangrene (A48.0), Nonpneumonic Legionnaires' disease [Pontiac fever] (A48.2), toxic shock syndrome (A48.3), Brazilian purpuric fever (A48.4), other specified botulism (A48.5) and other specified bacterial diseases (A48.8).

As a secondary diagnosis it is an MCC (major complication or comorbidity), which can move an inpatient stay into the highest-paying "with MCC" 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 177 (Respiratory Infections and Inflammations with MCC, relative weight 1.6092), DRG 178 (Respiratory Infections and Inflammations with CC, relative weight 0.9744), DRG 179 (Respiratory Infections and Inflammations without CC/MCC, relative weight 0.7345), DRG 791 (Prematurity with Major Problems, relative weight 4.1075), DRG 793 (Full Term Neonate with Major Problems, relative weight 4.2195), DRG 974 (HIV with Major Related Condition with MCC, relative weight 3.0506) and 2 more, in MDC 04 (Diseases and Disorders of the Respiratory System), MDC 15 (Newborns and Other Neonates with Conditions Originating in the Perinatal Period) 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.