The incidence of ST-elevation myocardial infarction (STEMI) among younger adults is increasing due to an increased prevalence of cardiometabolic risk factors. Readmissions after STEMI in young patients could lead to substantial health care costs and a significant burden on health care resources. Although STEMI readmissions are well studied in elderly patients, limited data are available regarding readmissions after STEMI in young patients and the etiologies remain poorly understood. Because younger patients with STEMI have different sociodemographic profiles th;an older patients with STEMI, one would postulate that the risk factors for readmissions in young patients would differ from that reported in the older patients with STEMI. We performed a contemporary nationwide study using the 2016 and 2017 Nationwide Readmissions Database to identify patterns of readmissions after STEMI in the young adult population. Our analysis of the Nationwide Readmissions Database revealed a total of 243,747 hospitalizations for STEMI between 2016 and 2017. Readmission rates demonstrated a steady increase from discharge, increasing to 7.8% at 30 days and 10.3% at 60 days before relatively plateauing at 12.1% at 90 days. Cardiovascular etiologies were the most common cause of readmission (53.6%). After multivariable analysis, development of cardiogenic shock (adjusted odds ratio 1.48, 95% confidence interval 1.11 to 1.97; p = 0.008) and acute renal failure (adjusted odds ratio 1.46, 95% confidence interval 1.14 to 1.87; p = 0.003) during the index admission were associated with significantly higher rates of readmission. In conclusion, close monitoring in young patients who presented with STEMI and concomitant with cardiogenic shock or acute renal failure, and possibly, aggressive therapy during index admission may be needed. However, this population may be heterogeneous and further research is needed.