This study examines how flexible work policies (e.g., time off, flextime, working from home) can help to change the “overwork” culture prevailing in American workplaces and its impact on employees’ work and health outcomes. Using the original survey of 4,013 employees, based on a probability-based panel designed to be representative of the U.S. household population, we find that “ideal worker” norms – which promote a single-minded commitment to work – largely persist in organizations offering flexible work polices. However, we also find that when these policies are implemented with additional organizational support -- gender-neutral framing, transparency in policy granting, and easy accessibility, and managerial support -- employees are less likely to associate “successful employees” with the ideal worker norm of working long hours, unlimited availability, and prioritizing work over other matters. Moreover, employees under these conditions report higher self-assessed job fit and job satisfaction and better health outcomes, compared to employees in organizations where flexible work policies are implemented in less supportive, more gendered, and more discretionary ways. These findings suggest that the efficacy of flexible work policies depends more on how these policies are implemented, rather than just their availability.