A22.1Pulmonary anthrax

A22.1 is the ICD-10-CM diagnosis code for pulmonary anthrax. It belongs to category A22 (anthrax), block A20-A28 (certain zoonotic bacterial diseases) and chapter 1 (certain infectious and parasitic diseases). It is billable, so it can be reported on its own for dates of service from October 1, 2026 through September 30, 2027.

Within A22 (anthrax), A22.1 is specifically for pulmonary anthrax. Related codes cover cutaneous anthrax (A22.0), gastrointestinal anthrax (A22.2), sepsis (A22.7), other forms of anthrax (A22.8) and unspecified (A22.9).

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) and DRG 179 (Respiratory Infections and Inflammations without CC/MCC, relative weight 0.7345), in MDC 04 (Diseases and Disorders of the Respiratory System), as a principal or secondary diagnosis. The DRG a claim lands in depends on the principal diagnosis, procedures and any CC/MCC secondary diagnoses.

It has been part of ICD-10-CM since the code set took effect on October 1, 2015 and hasn't changed since.

Before ICD-10, this condition was coded in ICD-9-CM as 022.1 (pulmonary anthrax), 022.1 (pulmonary anthrax) and 484.5 (pneumonia in anthrax).