ABSTRACT
While public administration research has made important strides in understanding social capital, less is known about how its effects vary across populations and contexts. This study investigates how racial segregation and citizen ideology shape the relationship between community social capital and flu vaccination rates among White and Black Medicare beneficiaries. Findings reveal that although social capital is associated with higher vaccination rates, its benefits are unequally realized, favoring Whites over Blacks. Racial segregation weakens the positive effect of social capital for Blacks and exacerbates health disparities. Liberal ideology amplifies the influence of social capital on vaccination rates for Whites, but this amplifying role is not statistically significant for Blacks or the racial gap. The results highlight the need for scholars to incorporate social equity more explicitly into social capital research, to measure group-specific social capital, and to account for the structural and cultural contexts that condition its effects.