ICD-10-CM Use Additional Code Notes ICD-10-CM
A Use Additional Code note means a second code should be added, after this one, to fully describe the condition. The FY 2027 Tabular List has 1,491 Use Additional Code Notes; 1,174 of them name other codes, with 1,438 references to 389 distinct codes, categories and ranges. Pick a chapter below to see every note in it, by the code that carries the note or by the code it names.
Wherever an etiology/manifestation combination exists, a "use additional code" note appears at the etiology code, and the manifestation code is reported after it. "Use additional code" notes are also used as sequencing rules for certain codes that are not part of an etiology/manifestation combination, where more than one code is needed to fully describe a condition (Section I.B.7).
Use Additional Code Notes by Chapter 22 chapters
“References to its codes” counts notes anywhere in the Tabular List that name a code in the chapter; “references in its notes” counts the codes named by notes printed in the chapter. Each chapter page shows both lists.
Questions About Use Additional Code Notes
What does a Use Additional Code note mean?
A Use Additional Code note tells you to add a second code, reported after the code that carries the note, to describe the condition completely. In an etiology/manifestation pair it sits at the etiology code and points to the manifestation (Section I.A.13). The FY 2027 Tabular List has 1,491 of them; 1,174 name other codes, with 1,438 references to 389 distinct codes, categories and ranges.
Where does the additional code go?
After the code carrying the note. For etiology/manifestation pairs the Guidelines are explicit: the etiology is sequenced first, followed by the manifestation code.
Is the additional code always required?
Only when the condition it describes is present and documented. Many notes read “use additional code, if applicable,” and name a range to choose from; the note tells you where to look, not that every patient has the condition.
Official Sources & Methodology
Every note on these pages is loaded verbatim from the FY 2027 ICD-10-CM Tabular List. Code references inside the notes are matched against the FY 2027 code set, so every link opens a valid code; scope counts (“applies to N codes”) count the billable codes under the note’s chapter, block or category.
- CMS ICD-10-CM FilesThe Tabular List (XML) that every note, note type and code reference on ICD List comes from.
- ICD-10-CM Official Guidelines for Coding and Reporting FY 2027Section I.A, Conventions for the ICD-10-CM, defines each note type; the definitions on these pages follow its wording.
ICD List is not affiliated with CMS or NCHS. These pages are a coding reference; the Tabular List and the Official Guidelines remain the authority.
Related References
Source: FY 2027 ICD-10-CM Tabular List (CMS and NCHS) and the ICD-10-CM Official Guidelines for Coding and Reporting FY 2027, Section I.A. ICD List is not affiliated with CMS or NCHS.
