In the Netherlands, students who want to become a medical specialist have to enrol in a training program which is in limited supply. During the search for a position as trainee (or "junior medical specialist"); they may accept a temporary job as a medical assistant. We use a micro data set to investigate whether such work experience increases the probability of becoming junior medical specialist. To deal with selectivity, we simultaneously model the transitions from unemployment to trainee, from unemployment to medical assistant, from medical assistant to trainee and from medical assistant to unemployment. We find that a job as medical assistant helps to become a medical specialist.