Collaborative instruction (collaborative teaching, co-teaching, cooperative teaching) is a joint teaching model in which the general education teacher and the specialist (special education teacher, therapist, or remedial general education teacher) share planning, teaching, and evaluation within the general education setting. This collaboration involves jointly developing and agreeing upon a set of common goals, sharing the responsibility for obtaining these goals and working together to achieve these goals using each other's expertise. Good co-teaching requires tolerant, reflective, non-territorial and flexible co-teachers.

A collaborative teaching model evolved from an in-class support model, which is a special education program option for students with educational disabilities enrolled in regular education classes. It was first made available in New Jersey public schools through the Plan to Revise Special Education in New Jersey, a pilot project that included "eligible for part-time special education" as a program option. It is intended for students that spend the majority of their day in the regular education class. There is a shared instructional responsibility between the regular class teacher and the special education teacher, geared to enable the student to succeed in the regular class program.

The chief difference between the collaborative and in-class support models lies in who has primary instructional responsibility. In the collaborative model, the general education teacher and the specialist share all responsibilities, including curriculum responsibilities and evaluation. With the in-class support model, the primary responsibility for the curriculum and class lesson remains with the general education teacher, while the special education teacher provides assistance to the student(s) to ensure that Individualized Education Program (IEP) modifications and accommodations are provided in the general education classroom to allow the student to access the general education curriculum. The special education teacher in the in-class support model also supports general education teachers by assisting with the design or re-formatting of lessons, tests, study guides, and other materials.

In Hopewell Valley Regional School District, the collaborative model is used throughout the system and is implemented for distinct class periods. The in-class support model is currently being implemented in the Central High School science department with a special education teacher supporting classroom instruction for several courses on a cyclical base.