ICD-10-CM > I00-I99 > I30-I5A > I33 I33 Acute and subacute endocarditis Non-Billable/Non-Specific Type 1 Excludes acute rheumatic endocarditis (I01.1)endocarditis NOS (I38) Codes I33.0Acute and subacute infective endocarditisI33.9Acute and subacute endocarditis, unspecified