This article presents longitudinal follow-up of the Flexibility in Duty Hour Requirements for Surgical Trainees (FIRST) Trial, which examined the effects of flexible duty-hour policies on resident outcomes. After four years, there was no evidence of increased duty-hour violations, decreased satisfaction or decreased well-being among residents randomized to flexible duty-hour policies. The researchers also observed that the beneficial impacts of flexible duty-hours persisted over the four-year period, whereas most of the negative effects diminished over time.