To examine whether, through interactions with preexisting socioeconomic status vulnerabilities, the COVID-19 pandemic exacerbated exposure to firearm violence among communities with a legacy of redlining (i.e., grading the creditworthiness of neighborhoods based on their sociodemographic composition). We used an exogenous population threshold whereby the Home Owners Loan Corporation graded neighborhoods only in US cities with populations of more than 40 000 and used a difference-in-difference strategy to examine the evolution of fatal firearm incidents between 2017 and October 2022. After the COVID-19 pandemic began, fatal firearm violence increased significantly in low-graded neighborhoods that the Home Owners Loan Corporation had deemed risky for mortgage lending. The effect held consistently across various model specifications. Social and environmental constructs can interact in a complex manner to compound disadvantage and exacerbate the consequences of negative shocks for marginalized communities. Home Owners Loan Corporation policies contributed to widening racial disparities in firearm violence, highlighting the need for reinvestment in marginalized communities to keep future shocks from exacerbating vulnerability to adverse outcomes. (. 2025;115(2):161-169. https://doi.org/10.2105/AJPH.2024.307891).