Q42.2 vs Q43.6
Q42.2 and Q43.6 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 Q43.6
congenital fistula of anus with absence, atresia and stenosis (Q42.2)
Q42.2
Congenital absence, atresia and stenosis of anus with fistula
Billable
- Chapter 17
- Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
- Section
- Q38-Q45
Indexed under
- Absence › anus › with fistula (of) (organ or part) (complete or partial)
- Agenesis › anus, anal › with fistula
- Atresia, atretic › ani, anus, anal › with fistula
- Hypoplasia, hypoplastic › anus, anal › with fistula
- Imperforate › anus › with fistula (congenital)
Q43.6
Congenital fistula of rectum and anus
Billable
- Chapter 17
- Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
- Section
- Q38-Q45
Indexed under
- Fistula › anus, anal › congenital (cutaneous)
- Fistula › fecal › congenital (cutaneous)
- Fistula › rectum › congenital (cutaneous)
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