Infectious agents as the cause of diseases classified to other chapters
Certain infections are classified in chapters other than Chapter 1 and no organism is identified as part of the infection code. In these instances, it is necessary to use an additional code from Chapter 1 to identify the organism.
A code from category B95, Streptococcus, Staphylococcus, and Enterococcus as the cause of diseases classified to other chapters, B96, Other bacterial agents as the cause of diseases classified to other chapters, or B97, Viral agents as the cause of diseases classified to other chapters, is to be used as an additional code to identify the organism.
An instructional note will be found at the infection code advising that an additional organism code is required.
ICD-10-CM Official Guidelines for Coding and Reporting, FY 2026 (effective October 1, 2025). Published by CMS and NCHS. Reproduced for reference — always verify against the official CMS release.