Background: The increased incidence of gastro-esophageal junction adenocarcinoma has been well-described, but how the proportion of early versus older onset cancer has changed over time remains incompletely understood. This study characterized the socioeconomic and pathologic characteristics of early-onset gastro-esophageal malignancies. Methods: All patients with gastric cancer (GC) and esophageal cancer (EC) from 2004-2015 in the National Cancer Database were included and categorized by age under or over 60 years. Differences in demographics, disease stage, treatment characteristics and socioeconomic factors between young and older patients were assessed by Chi-square test. The effect of age, race, insurance status, community median income and community educational attainment on overall survival (OS) were assessed using uni- and multivariable Cox models with Bonferonni correction when indicated. Results: The study population comprised 158,599 patients with GC and 139,210 patients with EC. For GC, 43,146 patients (27.2%) were under age 60. The proportion of patients diagnosed under 60 increased over time: 26.7% in 2004-2006, 26.9% in 2007-2009, 27.6% in 2010-2012 and 27.5% in 2013-2015. Compared to older patients, young patients were more likely to be Black (16.7% vs. 13.2%), Asian (7.6% vs. 6.1%) or Hispanic (15.5% vs. 7.7%), diagnosed with stage 4 disease (43.5% vs. 31.3%) and to have poorly differentiated grade (61% vs. 51.7%), p value < 0.0001 for all. For EC, 38,801 patients (27.8%) were under age 60. The proportion of patients diagnosed under 60, decreased over time: 29.6% in 2004-2006, 28.3% in 2007-2009, 27.6% in 2010-2012 and 26.2 % in 2013-2015. Compared to older patients, young patients were more likely to be Black (12.6% vs. 8.2%) or Hispanic (4.2% vs. 3.1%), diagnosed with stage 4 disease (34.3% vs. 26.1%), p value < 0.0001 for all. There was no difference in histologic grade between younger and older patients (41.1% vs. 40.3%, p = 0.85). Age < 60 years was associated with improved OS in both GC and EC. After adjusting for other demographic, socioeconomic, disease stage and treatment-related factors, Black patients had the worst median OS compared to other races in both malignancies as shown in the Table. Conclusions: Early-onset GC has increased over time while early-onset EC has decreased. Patients with early-onset gastric and esophageal cancer are more likely to be Black or Hispanic and to present with stage 4 cancer. Younger patients with GC are also more likely to have poorly differentiated histology. Most concerning, Black patients have the worst OS compared to other races for both GC and EC.