University of Maryland (UMD) Libraries has a large teaching program that serves between 16,000 and 20,000 students per academic year. This chapter documents the transformation of UMD Libraries’ teaching program from an individualistic approach to a strong community of practice based on the mutual affirmation, support, and respect of library teachers, and includes the following sections: (1) history of the UMD Libraries’ teaching program, with special attention to how the program has been shaped by the Libraries’ partnership with the UMD Academic Writing Program (ENGL101); (2) overview of the theoretical framework of Communities of Practice (COP); (3) exploration of COP at UMD Libraries, including analysis of two teacher training programs, the Research and Teaching Fellowship, and Fearless Teaching Institute; and (4) recommendations for practice.