Explanation
An Excludes 2 note in ICD-10-CM indicates that the condition excluded is not part of the condition represented by the code, but a patient may have both conditions at the same time. When an Excludes 2 note appears under a code, it is acceptable to use both the code and the excluded code together to completely describe the condition. For example, under code R05 Cough, there is an Excludes 2 note for whooping cough (A37.-). This means that a patient can have both a cough and whooping cough at the same time, and both codes can be used together to capture the full clinical picture.
References:
CDIP Exam Content Outline (https://www.ahima.org/media/1z0x0x1a/cdip-exam-content-outline.pdf) ICD-10-CM Features | Diagnosis Coding: Using the ICD-10-CM1