From the earliest reports regarding middle level education to the most recent ones, teacher learning has been central to effective middle level schools. Alexander, Williams, Compton, Hines, and Prescott (1968) asserted, Even the most enthusiastic and well-qualified teachers must have the support of congenial organizational framework, abundant resources, pertinent inservice programs, and appropriate procedures to assure continued optimum performance (p. 88). In the seminal Turning Points document, the Carnegie Council on Adolescent Development (1989) highlighted how teachers working collectively can solve problems, experience professional support and less isolation, and coordinate instructional programs. In Turning Points 2000: Educating Adolescents in the 21st Century, Jackson and Davis (2000) recommended that middle level schools not only be staffed with teachers who are expert at teaching young adolescents but also engage teachers in ongoing, targeted professional development opportunities. More recently in This We Believe: Keys to Educating Young Adolescents, National Middle School Association (NMSA, now Association for Middle Level Education [AMLE], 2010) named ongoing professional development as one of its 16 tenets, explaining, is ... initiatives (p. 30).It is important that professional development experiences provide continued participation over an extended period of time, collaborative approaches, and ongoing assessment of the effectiveness of the professional development initiatives. (p. 30)Professional development experiences can take many forms, yet collaborative organizational models, in particular, can facilitate teachers' discussions about professional readings, student work and data, instructional practices and assessment techniques, and school improvement goals. The professionalization of teaching is dependent upon teachers having opportunities to contribute to the development of their own knowledge, engage in collegial relationships, and grow intellectually throughout the process (Holmes Group, 1986). Such collegiality among teachers can exist teachers work together on shared project toward some shared goal through mutually constructed contributions (Angelle & Anfara, 2008, p. 52). Despite the focus on collaborative teacher learning, too many teachers, including middle grades teachers, still work in isolation and engage solely in individual professional development.The purpose of this article is to explore organizational models for teacher learning that are being used in middle level schools, including common planning time, professional learning communities, and critical friends groups. After offering brief definition of each model of teacher learning, we describe the theoretical underpinnings of the models, summarize the relevant research regarding the use of these models, and offer concluding remarks with implications for middle level education.Agreeing on language regarding the organizational models that support teacher learning is good starting point. First, common planning time is a regularly scheduled time during the school day when teachers who teach the same students meet for joint planning, parent conferences, materials preparation, and student evaluation (Kellough & Kellough, 2008, p. 394). It affords interdisciplinary teams of teachers- teachers from different content areas (e.g., language arts, mathematics, science, social studies)-time to collaborate. Second, professional learning communities are collaborative teams of teachers who routinely analyze their practice for the purpose of improving student achievement (DuFour, DuFour, & Eaker, 2008). Often, they are organized in discipline-specific groups or teams. Third, critical friends groups are groups of teachers who gather regularly to consider ways to improve student learning through collaboration and inquiry. Unique to critical friends groups is the use of structured protocols. …