Wenger's community of practice theory is used to illustrate how, through careful curriculum design, teacher identity can be developed by participation in a re-skilling programme. In the context of learning, a community of practice involves the complex intersection of various components of learning, namely, meaning (learning as experience), practice (learning as doing), identity and community (learning as belonging). The Advanced Certificate in Education in Mathematical Literacy programme was designed to expose participants to knowledge and understanding of the ML curriculum (meaning), development of an integrated approach to teaching and learning, classroom didactics, lesson plans (practice), and group work activities where active participation and dialogue in lectures were encouraged (community). The programme design aimed to promote a change in the teachers' way of being (identity). Through semi-structured interviews with teachers their journey as individuals was revealed. The findings indicate how by focusing on both content and on the teacher's becoming a professional can assist educational specialists in their quest for improved teacher development.