In this retrospective cohort study, neighborhood-level data were linked with health records of patients with the aim to report racial/ethnic disparities in uncontrolled hypertension and to examine if and to what extent the disparities are mediated by neighborhood socioeconomic status (nSES).

• From 2 healthcare delivery systems in San Francisco, a sample of patients with hypertension (n = 47,031) was included over 2 years in this mediation analysis.

• During the study period, uncontrolled hypertension was recorded in over half of the cohort (62%).

• Substantial differences in prevalence of uncontrolled hypertension and distribution of nSES quintiles were observed in racial/ethnic groups.

• There were higher adjusted odds of uncontrolled hypertension among Black, and Hispanic/Latino patients compared with White patients.

• nSES accounted for a small proportion of racial/ethnic disparities in uncontrolled hypertension.

• Per findings, population health management strategies that focus on additional structural and interpersonal pathways, such as racism and discrimination in healthcare settings, may be most effective.