Precarious work in the United States is defined by economic and temporal dimensions. A large literature documents the extent of low wages and limited fringe benefits, but research has only recently examined the prevalence and consequences of unstable and unpredictable work schedules. Yet practices such as on-call shifts, last minute cancellations, and insufficient work hours are common in the retail and food-service sectors. Little research has examined racial/ethnic inequality in this temporal dimension of job quality, yet precarious scheduling practices may be a significant, if mostly hidden, site for racial/ethnic inequality, because scheduling practices differ significantly between firms and because front-line managers have substantial discretion in scheduling. We draw on innovative matched employer-employee data from The Shift Project to estimate racial/ethnic gaps in these temporal dimensions of job quality and to examine the contribution of firm-level sorting and intra-organizational dynamics to these gaps. We find significant racial/ethnic gaps in exposure to precarious scheduling that disadvantage non-white workers. We provide novel evidence that both firm segregation and racial discordance between workers and managers play significant roles in explaining racial/ethnic gaps in job quality. Notably, we find that racial/ethnic gaps are larger for women than for men.