Abstract: The firm is almost entirely absent from models of immigration, and yet firms play a central role for high-skilled immigration. The H-1B visa program, for example, is a firm-sponsored entry where firms are responsible for every stage: from identifying the immigrant, to employing them, to filing for permanent residency on behalf of the immigrant. This central role of firms for high-skilled immigration suggests the traditional lens for evaluating the impact of immigration on natives through local area labor markets or national age-education approaches may miss important dynamics. We analyze the employment and wage trajectories of high-skilled workers born in America when a high-skilled immigrant arrives at their work site. We use linked employer-employee data during the 1995-2008 period from the Census Bureau for this exercise, which identifies the immigration status and country-of-birth of workers. We follow the subsequent career path of workers after high-skilled immigration occurs to the employee's work site both within firms (e.g., changes in employee salary, relocation to other sites) and across firms (e.g., movements to new jobs or out of workforce, long-term salary adjustments). The richness and depth of the Census Bureau data allow for multiple comparison points: selection on observables (e.g., age, tenure, salary levels and recent growth), varying immigration treatments across different work sites for the same firm for otherwise comparable employees, and (for a subset of cases and short time period at the end of our sample) randomization in H-1B admission lotteries.