409 Background: Incidence rates of Testicular cancer (TC) have been slowly increasing in the United States in recent decades. Prior research has identified racial disparities in mortality; however, these trends have not been extensively evaluated. Given that TC has a diverse presentation, this study was undertaken to establish racial, ethnic, geographical differences in longitudinal mortality trends. Methods: Age-adjusted cancer mortality rates for TC were obtained for men in the United States from the CDC Wide-ranging Online Data for Epidemiologic Research database. Testicular cancer-specific mortality (TCSM) rates from 1999-2019 were calculated using linear regression. Trends in mortality by race (White versus Black), ethnicity (Hispanic versus non-Hispanic), urbanization, and census region were analyzed using SAS 9.4. TCSM rates were compared by F-test. A two-sided hypothesis test was performed for p-values, where values < 0.05 were considered statistically significant. Results: From 1999-2019, overall age-adjusted TCSM has been slowly, but not significantly, increasing per year (Table). There was worsening TCSM rates for Hispanics (+)0.0019 per 100,000 compared to non-Hispanics (-)0.003; p=0.010. Black men had slightly improved TCSM rates/year (-0.0007) compared to white men (+0.0006); p=0.049. Significant geographical differences in mortality rates were observed, with a decreasing TCSM rate of (-)0.00092 the Northeast and an increasing rate of (+)0.00086 in the West (p = 0.032 for difference between slopes). Among urbanization categories, TCSM rates in Large Central Metros regions (central counties in metro areas with population > 1 million) and Small Metro regions (counties with population 50,000-249,999) were significantly different [(-)0.0004 and (+)0.0022 respectively; p =0.048]. All other comparisons were not significant. Conclusions: Using comprehensive, contemporary data on TCSM over 2 decades, we found significant differences in TCSM rates. Mortality rates from TC have been increasing, particularly among Hispanics. Understanding racial, ethnic, and geographical trends in TCSM rates is important in treating men with the disease and, ultimately, reducing deaths caused by TC.[Table: see text]