I77.0 vs Q27.3
I77.0 and Q27.3 can never be reported together. ICD-10-CM declares them mutually exclusive with an Excludes1 note, meaning the two conditions cannot occur in the same patient — so exactly one of them is correct for any given encounter.
The official note, declared on Q27.3
acquired arteriovenous aneurysm (I77.0)
I77.0
Arteriovenous fistula, acquired
Billable
- Chapter 9
- Diseases of the circulatory system
- Section
- I70-I79
Use when the record says
- Aneurysmal varix
- Arteriovenous aneurysm, acquired
Indexed under
- Fistula › arteriovenous (cutaneous)
- Varicose › aneurysm
- Varix › aneurysmal (lower limb)
- Aneurysm › arteriovenous › acquired (anastomotic) (artery) (cirsoid) (diffuse) (false) (fusiform) (multiple) (saccular)
- Aneurysm › arteriovenous › specified site NEC › acquired (anastomotic) (artery) (cirsoid) (diffuse) (false) (fusiform) (multiple) (saccular)
Q27.3
Arteriovenous malformation (peripheral)
Not billable
- Chapter 17
- Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
- Section
- Q20-Q28
Use when the record says
- Arteriovenous aneurysm
These two codes sit in different chapters of the Tabular List, which is usually the clearest signal that they describe different underlying processes rather than different degrees of the same one.
Excludes1 is not always absolute: where two conditions covered by the note are genuinely unrelated, CMS guidance permits reporting both. Document the reasoning rather than assuming it. More on Excludes1 vs Excludes2 · FY2027