ICDcodes.org
FY2027

Q40.1 vs Q79.0

Q40.1 and Q79.0 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 Q40.1
congenital diaphragmatic hernia (Q79.0)
Q40.1

Congenital hiatus hernia

Billable
Chapter 17
Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
Section
Q38-Q45
Use when the record says
  • Congenital displacement of cardia through esophageal hiatus
Indexed under
  • Displacement, displaced › cardia through esophageal hiatus
  • Hernia, hernial › hiatal › congenital (acquired) (recurrent)
  • Hernia, hernial › paraesophageal › congenital (acquired) (recurrent)
Q79.0

Congenital diaphragmatic hernia

Billable
Chapter 17
Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
Section
Q65-Q79
Indexed under
  • Hernia, hernial › diaphragm, diaphragmatic › congenital (acquired) (recurrent)
  • Defect, defective › diaphragm › congenital › with hernia
  • Defect, defective › diaphragm › congenital › gross

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