This study aims to gain insight into what is needed to ensure that the first career phase of nurses and police officers is as positive as possible, as well as into the (contextual) factors that contribute to positive transition experiences, from the perspectives of both newly qualified and fully competent professionals. Based on the results of the study, conclusions can be drawn about how positive transition experiences may reduce the likelihood that newly graduated professionals become mentally overburdened and that they leave the organization (or even the profession) during the early career phase. The central research question is: Which components during the first career phase, according to nurses and police officers, contribute to supporting the transition from a newly qualified nurse or police officer to an independent, confident, and fully competent professional?