I23.1 vs I51.0
I23.1 (Atrial septal defect as current complication following acute myocardial infarction) compared with I51.0 (Cardiac septal defect, acquired), from the official CMS tabular data. Do not report these codes together: the official tabular list marks them Excludes1.
Can these codes be reported together?
No — do not report together. I23.1 carries an Excludes1 note covering I51.0: “acquired atrial septal defect not specified as current complication following acute myocardial infarction (I51.0)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
No — do not report together. I51.0 carries an Excludes1 note covering I23.1: “cardiac septal defect as current complication following acute myocardial infarction (I23.1, I23.2)”
Sole exception: when the two conditions are documented as unrelated to each other (ICD-10-CM Official Guidelines, Section I.A.12.a).
Side by side
| I23.1Atrial septal defect as current complication following acute myocardial infarction | I51.0Cardiac septal defect, acquired | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | I00-I99 — Diseases of the Circulatory System (I00-I99) | I00-I99 — Diseases of the Circulatory System (I00-I99) |
| Definition | Atrial septal defect as current complication following acute myocardial infarction is a billable ICD-10-CM diagnosis code (I23.1). | Cardiac septal defect, acquired is a billable ICD-10-CM diagnosis code (I51.0). |
| Includes | — | Acquired septal atrial defect (old) Acquired septal auricular defect (old) Acquired septal ventricular defect (old) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources