Immigrants have been entering the U.S. since its inception; however, predominant immigration flows have changed over time. Following the 1965 Hart-Celler Act, which repealed national quotas for immigration, two pan-ethnic communities that grew significantly include the Middle Eastern North African (MENA) and South Asian immigrant communities (Bhandari, 2022; Harjanto & Batalova, 2022). MENA and South Asian Americans have established themselves as prominent pan-ethnic communities in the U.S. with a large immigrant network throughout the country (Basu, 2016; Cainkar, 2018; Hashad, 2003; Sekhon, 2003). However, following 9/11 they have also experienced record levels of hate crimes, violence, and discrimination, which have been shown to adversely affected their health and health access (Budiman, 2020; Martin, 2015; Reitmanova & Gustafson, 2008; Samuels et al., 2021; Samari et al., 2020). Other groups of immigrants have also suffered from government policies and practices that were enacted in response to 9/11; debates related to illegal immigration and visa overstays intensified over the following few decades and greatly impacted immigrants from Mexico, Central America, South America, the Caribbean, and all over Asia (Passel & Cohn, 2014). These events have had a “chilling effect” on the psyche of immigrants from MENA and South Asian backgrounds, as well as Latin and Asian immigrants Quesada et al., 2011). In the studies of this dissertation, I examined how factors pertaining to the migration process have shaped health access and sexual and reproductive healthcare (SRH) of immigrant groups in a post-9/11 world—an era in which immigrants of various race/ethnicities have been vilified in a prevailing anti-immigrant sociopolitical climate. In the first two studies of this dissertation, I explored the neighborhood context that MENA and South Asian immigrants resettle into (Aim 1; Chapter 6) and how these environments shape their health access (Aim 2; Chapter 7). In the third study, I focus on the role of citizenship status on contraception use among reproductive-aged (18-44 years) immigrant women (Aim 3; Chapter 8). This dissertation used secondary data from large demographic surveys including the 2020 American Community Survey (ACS) 5-Year Estimates (Aims 1 and 2) and pooled data from 2017 to 2020 waves of the California Health Interview Survey (CHIS). Data from the first study indicated that MENA and South Asian Americans in California are spread across different metropolitan areas of Northern and Southern California and that they have formed four different types of ethnic neighborhoods that follow a few different social and economic pattern, in terms of the density of these specific immigrant groups, their overall foreign-born concentration, and socioeconomic status. The second study indicated that diversity within these groups, including in terms of their health insurance status, can be observed through the distinct type of neighborhoods in which they resettle. For example, among MENA Americans, socioeconomic advantage in a neighborhood was associated with health insurance status. For South Asians, health insurance status was associated with co-ethnic density and foreign-born density. Finally, in the third study of this dissertation I found that nativity and citizenship status were not significantly associated with contraception use, however, there were notable bivariate differences in type of contraception method used by citizenship status. The findings of this dissertation are important for understanding how different aspects of migration shape health of underrepresented immigrant groups, including MENA and South Asian Americans and non-citizen immigrant groups including legal permanent residents (LPRs) and those without a green card. Researchers and policy makers should use the findings of this dissertation to work toward reducing barriers to health access and SRH in immigrant populations.