Background: Although global incidence of gastric cancer has been decreasing over the past decades, an upward trend has been reported in younger patients and certain ethnic groups over the past few years. The reason for this epidemiological trend is not fully understood, but differences in presentation and prognosis suggest that gastric cancer in the young might represent a different clinical entity. Here, we seek to identify differences in demographic characteristics and outcomes between young adults and older patients admitted for gastric cancer. Methods: Using the National Inpatient Sample (NIS) database, we identified all adult patients admitted primarily for gastric cancer from 2016 to 2019. We analyzed demographic characteristics of young adults (defined as those aged between 20 and 49-years-old) and older patients (aged 50 and above) as well as differences in in-hospital mortality, total hospital charges, and length of stay. Multivariate logistic regression analysis was conducted to adjust for confounders. Results: During the period studied, 77,720 patients were admitted with gastric cancer, of which 9,650 (12.4%) were young adults and 68,115 (87.6%) were old individuals. Young adults were more likely to be female (42.4 vs. 35.6%, p < 0.01). Hispanics comprised 30.9% of admissions for gastric cancer of young adults (vs. 15% in older adults p-value <0.01). Young adults were also over 3 times more likely to be uninsured than older individuals (9.6 vs. 2.6%, p-value <0.01) and more likely to be cared for in urban (98.2 vs. 96.2%, p < 0.01) and teaching (85.4 vs. 80.8%, p < 0.01) hospitals. Young adults had longer lengths of stay and lower hospital charges (see table). No difference was found in mortality, despite a lower comorbidity burden in young adults based on the Charlson Comorbidity Index, possibly due to young adults being candidates for more aggressive therapy and having more aggressive disease. Conclusions: The higher incidence of gastric cancer in Hispanic and uninsured young adults poses a complex public health issue, especially in the context of recent research suggesting more aggressive disease in this population. The reported findings likely reflect both a shift in the U.S. population over the years as well as a rising incidence among Hispanic young adults. It is important to increase awareness of these epidemiological disparities. Further research is needed to determine whether establishing screening programs for gastric cancer in certain populations might be beneficial in the U.S.