This paper focuses on the contextual determinants of bilingualism among Latino adults who were born in the US or are members of the ‘1.5 generation’ of Latinos who immigrated to the US when they were 10 or younger. We model the broader contexts reflecting contemporary developments that influence change in both the real and the perceived value of bilingualism. Using US census data for metropolitan areas in 1990 and 2000, we find that the replenishment of an immigrant population is a strong predictor of higher bilingualism among US-born Latinos. We draw on ethnographic data on later-generation Mexican Americans as well as field-work in dual-language immersion schools to explain our findings. The variables measuring the size and growth of the foreign-born Latino population in the MSA/PMSAs in our models capture the factors that encourage bilingualism that we identify in our ethnographic research: institutional contact with Spanish, labour-market rewards, cosmopolitanism.