IMPORTANCE: Achieving equitable access to medicines requires understanding of how pharmaceutical use and spending vary by race and ethnicity across the US. OBJECTIVE: To quantify variation in prescription drug utilization and spending per capita and per prevalent case by race, ethnicity, health condition, payer, and US state. DESIGN, SETTING, AND PARTICIPANTS: In this cross-sectional study, the US Disease Expenditure project was extended to incorporate disaggregation by race and ethnicity for state-level retail prescription drug utilization and spending-in addition to 143 health conditions, 38 age and sex groups, and 4 payers (Medicare, Medicaid, private insurance, and out of pocket)-across the 2019 population in all 50 states and Washington, DC. Data were analyzed from October 2023 to April 2025. EXPOSURE: Four mutually exclusive racial and ethnic groups (Asian or Pacific Islander, Black, Hispanic, and White). MAIN OUTCOME AND MEASURES: Outcomes include prescriptions dispensed and spending for retail pharmaceuticals. Estimates were standardized by population size, population age, and-where data permitted-by disease burden (52 conditions). Das Gupta decomposition was used to estimate the relative contribution of 3 factors (disease prevalence, prescriptions per prevalent case, and spending per prescription) on observed disparities in age-standardized per capita pharmaceutical spending. RESULTS: In 2019, age-standardized pharmaceutical utilization and spending per person with a given disease was substantially lower than the all-population mean for Black populations, close to the mean for Hispanic populations, and often higher than the mean for Asian or Pacific Islander and White populations. These trends-particularly those for the Black population-were generally consistent across 52 health conditions but varied widely across payers and US states. The decomposition analysis for these 52 conditions showed that differences in per capita pharmaceutical spending across race and ethnicity groups were primarily explained by disease prevalence for Black populations (associated with increased per capita spending) and by utilization rates per prevalent case for Hispanic populations (also associated with increased spending). In contrast, differences in drug price or product type (spending per prescription) contributed less to observed spending disparities. CONCLUSIONS AND RELEVANCE: In this cross-sectional study, racial and ethnic disparities in medication use persisted, most notably the underutilization of medicines relative to disease burden among Black populations. These patterns varied by state, highlighting the need for local- and condition-specific approaches to advancing pharmacoequity in the US.