Excludes1 pair
Q24.5 vs Q28-
Q24.5 and Q28 are not coded together. ICD-10-CM declares them mutually exclusive with an Excludes1 note — the two conditions are not expected to occur together, so exactly one of them is normally correct for a given encounter. The Official Guidelines carve out one exception: if the two conditions are clearly unrelated to each other, both may be reported.
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
- Anomaly, anomalous › coronary artery or vein
- Anomaly, anomalous › distribution, coronary artery
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