Most injured workers return to their jobs successfully. For a few, however, problems may arise that complicate their recovery and return to work. This guide, based on IWH research, is designed for such situations. It presents warning signs (or red flags) and helpful practices (or green lights) in four return-to-work contexts: work, health-care, vocational rehabilitation and claims. It also includes at-a-glance cards summarizing the red and green flags in each of the four contexts.