With all the changes in ICD-10 guidelines and diganosis codes it can be confusing when attempting to assign the correct diagnosis codes. ICD-10 offers some direction in the form of coding conventions.
One of such conventions is the Exclude notes 1 & 2.
Exclude 1 Note= when two conditions (with two separate codes) cannot occur together (NOT CODED HERE!) The excluded code should never be used at the same time as the code above the Excludes 1 note.
Example-M20 Acquired deformities of fingers and toes is at the category level. It is not a complete, reportable code. But there are Excludes1 notes at this level, telling you not to report the following conditions and codes alongside any code beginning with M20:
Acquired absence of fingers and toes (Z89)
Congenital absence of fingers and toes (Q71.3, Q72.3)
Congenital deformities and malformations of fingers and toes (Q66, Q68-Q70, Q74).
Exclude 2 Note= appears when a code is not appropriate for a specific condition and you should look elsewhere to code the excluded condition. If the pt. has both conditions you may report both codes together.
Example-I10 Essential (primary) hypertension has a note that lets you know that if the essential hypertension involves brain vessels, you should use a code from I60-I69 instead because I10 does not represent that condition. But if the patient is diagnosed with both essential hypertension and essential hypertension involving vessels of the brain, it is acceptable to report both I10 and a code from I60-I69 on the same claim.