I38 vs Q24.8
I38 and Q24.8 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 I38
congenital insufficiency of cardiac valve NOS (Q24.8)
I38
Endocarditis, valve unspecified
BillableUnspecified
- Chapter 9
- Diseases of the circulatory system
- Section
- I30-I5A
Use when the record says
- endocarditis (chronic) NOS
- valvular incompetence NOS
- valvular insufficiency NOS
- valvular regurgitation NOS
- valvular stenosis NOS
- valvulitis (chronic) NOS
Indexed under
- Endocarditis (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)
- Disease, diseased › valve, valvular
- Endocarditis › arteriosclerotic (chronic) (marantic) (nonbacterial) (thrombotic) (valvular)
- Insufficiency, insufficient › valve, valvular
- Stenosis, stenotic › heart valve (cicatricial)
Q24.8
Other specified congenital malformations of heart
BillableUnspecified
- Chapter 17
- Congenital malformations, deformations, chromosomal abnormalities, and genetic disorders
- Section
- Q20-Q28
Use when the record says
- Congenital diverticulum of left ventricle
- Congenital malformation of myocardium
- Congenital malformation of pericardium
- Malposition of heart
- Uhl's disease
Indexed under
- Cordis ectopia
- Ectocardia
- Hemicardia
- Uhl's anomaly or disease
- Absence › pericardium (of) (organ or part) (complete or partial)
These two codes sit in different chapters of the Tabular List, which is usually the clearest signal that they describe different underlying processes rather than different degrees of the same one.
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