There has been little research on the relationship between education and healthcare utilization, especially for racial/ethnic minorities. This study aimed to examine the association between education and hospitalizations, investigate the mechanisms, and disaggregate the relationship by gender, race/ethnicity, and age groups. A retrospective cohort analysis was conducted using data from the 1992–2016 US Health and Retirement Study. The analytic sample consists of 35,451 respondents with 215,724 person-year observations. We employed a linear probability model with standard errors clustered at the respondent level and accounted for attrition bias using an inverse probability weighting approach. On average, compared to having an education less than high school, having a college degree or above was significantly associated with an 8.37 pp (95% CI, −9.79 pp to −7.95 pp) lower probability of being hospitalized, and having education of high school or some college was related to 3.35 pp (95% CI, −4.57 pp to −2.14 pp) lower probability. The association slightly attenuated after controlling for income but dramatically reduced once holding health conditions constant. Specifically, given the same health status and childhood environment conditions, compared to those with less than high school degree, college graduates saw a 1.79 pp (95% CI, −3.16 pp to −0.42 pp) lower chance of being hospitalized, but the association for high school graduates became indistinguishable from zero. Additionally, the association was larger for females, whites, and those younger than 78. The association was statistically significantly smaller for black college graduates than their white counterparts, even when health status is held constant. Educational attainment is a strong predictor of hospitalizations for middle-aged and older US adults. Health mediates most of the education-hospitalization gradients. The heterogeneous results across age, gender, race, and ethnicity groups should inform further research on health disparities.