Continuing professional development (CPD) through in-service learning is considered crucial for teachers throughout their professional careers. The literature on teachers’ professional biographies suggests a sequence of typical phases during their careers. However, the role of specific learning opportunities has hardly been investigated so far. Furthermore, previous findings focus predominantly on the frequency of participation in professional development and other learning activities, without considering their intensity of use or perceived usefulness for professional development. Using a subsample (N = 658) of the 2018 TEDCA survey, this study explores the self-estimated intensity with which teachers engage in CPD on different professional practice areas and how they rate the usefulness of various formal, informal, and incidental learning opportunities in relation to their professional experience. For organized training, analyses using structural equation modelling point towards an increase of intensity and usefulness up to about 20 years of work experience and a decrease thereafter. For incidental learning opportunities (experiences in everyday work life), there is a decline in the perceived usefulness. In the informal area, the usefulness of learning through exchanges with colleagues and school leaders decreases, while no experience-related effects emerge for other informal learning opportunities (e.g., media-supported knowledge acquisition, impulses from students and parents). The findings thus point to a differential relevance and usefulness of specific learning opportunities for professional development across teachers’ career. Implications for possible differential, experience-dependent designs of learning activities for teachers are discussed.