Teachers have historically been at the margins of educational improvement, and they are just beginning to drive improvements in the profession. Networked improvement communities (NICs) are one approach for collective reprofessionalization of teaching, where practice is defined and managed by practitioners. Edit Khachatryan and Emma Parkerson offer insight into the social organization of a NIC and use two real and mature networks -- the Network to Transform Teaching and the National Writing Project -- to describe how NICs structure roles and relationships and foster vital norms and identities among professionals.