Q24.5 vs Q28
Q24.5 and Q28 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 Q28
congenital coronary aneurysm (Q24.5)
Q24.5
Malformation of coronary vessels
Billable
- Chapter 17
- Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
- Section
- Q20-Q28
Use when the record says
- Congenital coronary (artery) aneurysm
Indexed under
- Bridge, myocardial
- Abnormal, abnormality, abnormalities › coronary artery
- Accessory › coronary artery (congenital)
- Anomaly, anomalous › coronary artery or vein (congenital) (unspecified type)
- Anomaly, anomalous › distribution, coronary artery (congenital) (unspecified type)
Q28
Other congenital malformations of circulatory system
Not billable
- Chapter 17
- Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
- Section
- Q20-Q28
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