Guidelines › Etiology and manifestation: code first and use additional code

Etiology and manifestation: code first and use additional code

Official text from the FY2027 ICD-10-CM Official Guidelines for Coding and Reporting. The wording is quoted exactly.

Guidelines I.A.13

“Wherever such a combination exists, there is a "use additional code" note at the etiology code, and a "code first" note at the manifestation code.”

“"In diseases classified elsewhere" codes are never permitted to be used as first listed or principal diagnosis codes.”

Where this applies

This is a general rule. It applies to code assignment everywhere, not to one code or group of codes.

Source: FY 2027 ICD-10-CM Official Guidelines for Coding and Reporting, effective October 1, 2026. Full Guidelines (PDF, CMS)