Administrative claim-based databases are being increasingly used in clinical research to assess trends, patters of care, cost, and to perform comparative effectiveness analyses. In cardiovascular medicine, the number of published analyses the utilized administrative databases increased from 2 in 1996 to 268 in 2018 (P < .001). However, a major limitation of administrative database related research is the lack of certainty about the validity of the billing codes used to identify procedures and clinical events. The adoption of the 10th edition of the International Classification of Diseases-Ninth Revision-Clinical Modification (ICD-10-CM) is hoped to increase coding accuracy, and hence the reliability of related research. However, studies validity ICD-10-CM codes of key clinical events in cardiovascular medicine are scarce. Hence, we sought to assess the validity of ICD-10-CM codes in identifying patients admitted with acute myocardial infarction (AMI) using our institutional database.