Textbook problems and tasks often do not meet a teacher’s specific learning goals, which may inspire the teacher to create their own mathematical problems. However, the question of whether this practice translates into advancing teachers’ problem-posing skills remains open. This chapter introduces a theoretically based professional development model for problem posing that aims to develop teachers’ skills in posing mathematics problems. In this model, teachers pose problems intended to meet their classroom learning objectives, discuss these problems with their peers, teach the problems to their students, reflect on their classroom experiences, and initiate a new problem-posing cycle, if deemed necessary. To illustrate the model in action, we use data from a master’s course for in-service high-school teachers.