This unique special issue features five articles that provide guidance for middle school special education and general education content-area co-teachers on how to implement enhanced co-teaching models including specialized literacy instruction and best practices for co-teachers (e.g., co-planning; using station teaching to differentiate instruction). The authors of each article were part of a research team that conducted a 2015-2018 development and innovation professional development project funded by the U.S. Department of Education, Institute of Education Sciences, Project CALI (Content Area Literacy Instruction). Project CALI resulted in the development of the CALI professional development designed to provide co-teachers guidance on how to implement a set of evidence-based literacy practices (i.e., the CALI instructional framework) to improve outcomes for students with learning disabilities (LD) in co-taught classes. Authors in this special issue use examples from the CALI professional development to illustrate each practice.