Background Data are limited about young adults' characteristics and outcomes undergoing coronary artery bypass grafting (CABG). Methods and Results We used the National Inpatient Sample database to identify adults aged 18 to 45 years who underwent CABG between 2004 and 2018. The data were weighted to generate national estimates of the entire US hospitalized population. We identified 110 463 CABG cases, equivalent to 62.2 per 1 000 000 person‐years; 27.1% were women, and 70.2% were White adults. Overall, annual CABG volume per 1 000 000 significantly decreased from 87.3 in 2004 to 45.7 in 2018. The prevalence of obesity, diabetes mellitus, hypertension, drug abuse, and chronic medical conditions increased over time. Overall, inpatient mortality was 1.76%; ST‐segment–elevation myocardial infarction, non–ST‐segment–elevation myocardial infarction, heart failure, peripheral vascular disease, renal failure, and valvular surgery were associated with higher inpatient mortality. Women had higher inpatient mortality than men (2.29% versus 1.57%), and Black patients had higher deaths than White patients (2.86% versus 1.58%). Inpatient mortality remained stable overall, according to sex, race, or clinical indication of CABG. However, the mean length of stay (8.4 days in 2004 to 9.5 days in 2018) and inflation‐adjusted cost of care ($40 522.8 in 2004 to $52 434.2 in 2018) significantly increased during the study period. Conclusions Despite the increased burden of cardiometabolic risk factors, the inpatient mortality in young adults undergoing CABG remained stable during the last 15 years. However, CABG volumes have decreased, but length of stay and inflation‐adjusted costs have increased over time.