Little research has been conducted on the professional identities of L2 writing scholars despite the increasing number of researchers, teachers, and graduate students identifying themselves as L2 writing specialists. While the (re)construction of L2 writing scholars’ professional identities have real consequences for their career, the challenges and opportunities resulting from their work, situated in several related disciplines, have neither been explicitly nor adequately discussed. Through an analytic autoethnography (Anderson, 2006), this study examines the cases of two L2 writing faculty as they (re)construct their professional identities within their institutions and broader academic communities. Using identity in practice as its theoretical framework, the study provides a rich, in-depth account of how the focal L2 writing scholars continue to negotiate and reconcile their professional identities among adjacent fields such as applied linguistics, TESOL, composition, and education. Results reveal that L2 writing scholars (re)construct their professional identities by negotiating their identity positions within their institutional and disciplinary contexts, by defining the boundaries of their professional identities through community membership, and by participating in multiple academic communities. Drawing on these results, the study considers how L2 writing scholars’ professional identity (re)construction reflects the development of L2 writing as a field/profession.