Legal status shapes the resources, environment, and opportunities that immigrants can mobilize for the benefit of themselves and their families. Barriers to legal status attainment affect not only immigrants themselves, but also their children, many of whom are host country citizens. This dissertation analyzes data from the California Health Interview Survey (CHIS) and Trajectories and Origins Survey (TeO) to uncover how citizenship denial and vulnerable legal status affect immigrants' and their children's outcomes. Chapter 2 uses TeO (2008-2009) to examine how experiences of status citizenship denial (naturalization denial) and cultural citizenship denial (e.g., bureaucratic mistreatment and perceptions of foreignness) affect the enactment of citizenship among immigrants in France. I find that while status and cultural citizenship denial are associated with diminished identification with France, cultural citizenship denial corresponds with heightened identification with one’s country of origin and increased rates of French and transnational civic participation. Chapter 3 analyzes data from CHIS (2014-2016) to consider how immigrants' access to preventive care in the United States is stratified by their legal status. Results show that undocumented immigrants and temporary status holders report lower unadjusted rates of having annual checkups, flu vaccinations, and mammograms relative to permanent residents and naturalized citizens. We find that legal status disparities in checkups and vaccinations, but not mammograms, lose statistical significance after controlling for sociodemographic, health status, and health access factors. Chapter 4 uses the CHIS child sample (2014-2019) to consider how parents' undocumented status shapes their US-citizen children's health. We find that parents' undocumented status has a negative but indirect effect on their children's health through increasing household risk of poverty and food insecurity. This dissertation informs understandings of how precarious legal status and barriers to legal status attainment affect the wellbeing of immigrants and their families.