Definition
Co-teaching is an instructional arrangement in which two certified teachers share a single classroom, jointly responsible for planning, delivering, and assessing instruction for a heterogeneous group of students. Both teachers are present for the full lesson, though their specific roles shift depending on which of several structured models they are using at any given time.
The arrangement became formalized as a response to federal special education mandates in the United States, particularly the Individuals with Disabilities Education Act (IDEA), which requires students with disabilities to be educated in the least restrictive environment. In practice, co-teaching typically pairs a general education teacher with a special education teacher, though the model extends to content-area specialists, English language development teachers, gifted education teachers, and reading specialists.
Critically, co-teaching is not simply two adults in the same room. Marilyn Friend and Lynne Cook, whose 1992 framework remains the field's primary reference, define it as two or more professionals delivering substantive instruction to a diverse group of students in a single shared space. The word "substantive" does real work in that definition. Both teachers must be actively teaching, not one teaching while the other monitors behavior.
Historical Context
The intellectual roots of co-teaching trace back to team teaching experiments in the late 1950s and 1960s, when schools in Trump's "Model Schools Project" (1959) explored flexible staffing to differentiate instruction at scale. Those early experiments were largely abandoned, viewed as administratively complex without clear outcome benefits.
The modern co-teaching model took shape in response to the mainstreaming provisions of Public Law 94-142, passed in 1975, which began moving students with disabilities out of segregated settings. Schools needed a mechanism for including those students in general education without abandoning specialized support. "Push-in" special education services became an informal precursor to structured co-teaching.
The framework most teachers encounter today comes from Marilyn Friend (University of North Carolina Greensboro) and Lynne Cook, whose 1992 textbook Interactions: Collaboration Skills for School Professionals codified six distinct co-teaching models. Friend subsequently extended this work through her 2008 book Co-Teach!, which added substantial guidance on co-teacher relationships and administrative structures. Her six-model taxonomy has been adopted in teacher preparation programs across the United States, Australia, Canada, and the United Kingdom.
Vaughn, Schumm, and Argüelles (1997) conducted some of the earliest empirical studies comparing co-teaching to other delivery formats, establishing a research baseline that subsequent meta-analyses have refined. Murawski and Swanson's 2001 meta-analysis in Remedial and Special Education was the first large-scale synthesis of the effectiveness literature, with mixed but cautiously positive findings that shaped the next two decades of research.
Key Principles
Shared Responsibility
Both teachers own all students in the room. In a co-taught class, there is no "your kids" and "my kids" split. Special education teachers do not work exclusively with students on IEPs while the general education teacher leads the rest of the class. That arrangement, common in poorly implemented co-teaching, is one-teach/one-assist used as a default, which Friend describes as the model most likely to undermine the partnership's goals. Shared ownership requires deliberate agreement at the planning stage.
Deliberate Model Selection
The six models are tools, not a hierarchy. Teachers choose a model based on the learning objective, the students' needs that day, and the physical layout of the room. A lesson introducing a complex new concept might call for Team Teaching, where both teachers co-present. A lesson requiring differentiated practice might use Station Teaching or Parallel Teaching. Effective co-teaching pairs cycle through multiple models within a week and consciously avoid defaulting to One Teach/One Assist for every session.
Protected Planning Time
Co-teaching partnerships without designated planning time collapse into choreographed improvisation. Friend and Cook identify shared planning as the single most important structural support for co-teaching quality. Planning sessions must address who will lead which instructional segments, how materials will be differentiated, how both teachers will monitor student understanding, and how they will handle behavioral situations consistently. Research by Murawski (2010) found that co-teaching dyads with fewer than 30 minutes of joint planning per week showed no measurable gains over solo-teacher classrooms.
Parity in the Classroom
Students should perceive both adults as equally authoritative. Parity is established through deliberate behavior: both teachers address the whole class, both redirect behavior, both review student work. When one teacher consistently stands at the back or circulates silently while the other lectures, students quickly categorize the second adult as a helper rather than a teacher. This has downstream effects on how students receiving special education services perceive their own status in the room.
Differentiation Without Stigma
One of the central promises of co-teaching is that two teachers enable stronger differentiated instruction without segregating students who need additional support. When only one teacher is present, pulling a small group to reteach a concept visually marks those students as struggling. With two teachers and structured models like Alternative Teaching or Station Teaching, flexible regrouping happens routinely for all students, reducing stigma around additional support.
Classroom Application
Station Teaching Across Grade Levels
Station Teaching divides students into three or more groups rotating through teacher-led and independent stations. Each teacher leads one station, while a third station runs independently or with a paraprofessional. This is among the most versatile models for flexible grouping.
In a fifth-grade mathematics class, one teacher leads a station focused on concrete manipulative work with fraction division, while the other leads a station using number lines and visual models. A third station has students practicing independently with problems selected at different complexity levels. Students rotate every 15-18 minutes. Both teachers see every student, both teachers assess in real time, and the groupings can shift daily based on formative data.
In a ninth-grade English class, one teacher leads a close-reading station analyzing rhetorical devices in a short excerpt. The second teacher leads a writing station where students draft their own persuasive paragraphs and receive immediate feedback. A third station has students peer-reviewing drafts using a structured protocol. The structure supports students with learning disabilities without any student being permanently assigned to the "easier" station.
Parallel Teaching for Active Processing
In Parallel Teaching, the class splits into two roughly equal groups and each teacher delivers the same lesson simultaneously in different parts of the room. The smaller group size increases participation and the frequency of each student's response opportunities.
In a seventh-grade science class reviewing cell organelle functions before a unit assessment, two groups of 13 students each work with their teacher to build a visual model using everyday objects. Every student handles materials, responds to questions, and explains their reasoning in a group small enough that no one sits silent. In a full class of 26, many students coast through the review without engaging. Parallel Teaching eliminates that option.
Alternative Teaching for Targeted Reteaching
Alternative Teaching uses one teacher to work with a small group (typically 4-6 students) while the other continues instruction with the larger group. This is the model best suited to targeted reteaching after a formative check-for-understanding reveals specific gaps.
The key to using Alternative Teaching well is varying which students are in the small group. When the same students are always pulled aside, the arrangement recreates the tracked classroom co-teaching was designed to avoid. The small group might sometimes include advanced students extending the concept, students who were absent the prior day, or students who want a second explanation of something they found confusing — rotating the composition preserves the heterogeneous culture of the room.
Research Evidence
Murawski and Swanson's 2001 meta-analysis examined six studies meeting rigorous inclusion criteria and found an overall effect size of 0.40 for co-taught versus non-co-taught settings on student achievement. The authors noted the effect was stronger for students with disabilities than for general education peers, and that implementation quality moderated outcomes substantially. A poorly implemented co-teaching class showed near-zero effects.
Hang and Rabren (2009) surveyed 42 co-taught classrooms in Alabama and found that teacher satisfaction and student performance were both significantly correlated with the amount of planning time available per week. Teachers with 90 or more minutes of weekly planning rated their partnerships more positively and showed higher student proficiency rates on state assessments. This is one of the clearest studies linking structural supports to outcome quality.
McDuffie, Mastropieri, and Scruggs (2009) used observational data across 14 co-taught science classrooms and found that One Teach/One Assist was the dominant model used in 11 of the 14 classrooms, even when teachers reported using multiple models in surveys. The study highlights a consistent gap between intended and actual practice, suggesting that professional development for co-teaching must include observation and feedback cycles, not just model descriptions.
Sileo (2011) reviewed the literature on co-teacher relationships and identified interpersonal compatibility and administrative support as factors that predicted implementation fidelity more reliably than training alone. Teachers assigned to co-teaching partnerships without input into the pairing showed significantly lower satisfaction and poorer outcomes than those who had some voice in the match.
Common Misconceptions
Co-teaching is primarily for students with disabilities. Co-teaching emerged from special education law, but the research consistently shows benefits for English language learners, students identified as gifted, and general education students without any identified need. The reduced student-to-teacher ratio in well-implemented models creates more response opportunities, faster feedback loops, and richer classroom discussion for everyone. Framing co-teaching as a special education service often leads schools to assign it only to classes with high concentrations of students with IEPs, undermining inclusion rather than supporting it.
Any two teachers can co-teach effectively with minimal coordination. Administrative schedules sometimes create co-teaching pairings without providing planning time, training, or teacher input into the match. Teachers expected to co-teach in these conditions typically default to One Teach/One Assist out of necessity, which produces the weakest outcomes of any model. Effective co-teaching requires deliberate preparation, structured collaboration, and time. The arrangement is not self-organizing.
Co-teaching and team teaching are synonyms. Team Teaching is one of Friend and Cook's six specific models, characterized by both teachers simultaneously leading instruction for the whole class, often finishing each other's explanations or debating a concept in front of students. "Team teaching" in casual use often refers to any arrangement with two teachers. Using the terms interchangeably obscures the meaningful differences between models and makes it harder for co-teaching partners to communicate clearly about who does what.
Connection to Active Learning
Co-teaching creates the structural conditions for active learning methodologies to function at higher quality and reach more students. Many active learning approaches that struggle in a single-teacher classroom become feasible when a second certified teacher is present.
Station Teaching is the clearest overlap: the model is structurally identical to learning stations, with the added benefit that two stations are teacher-led rather than one. Students receive direct instruction and real-time feedback twice per rotation instead of once, and both teachers can observe student work and adjust based on what they see. Stations within a co-taught class also make flexible grouping sustainable as a daily practice rather than an occasional intervention.
Co-teaching also strengthens the implementation of Universal Design for Learning. UDL asks teachers to proactively design multiple means of representation, action, and engagement. In a solo classroom, providing multiple representations often means pre-recording a video or creating written alternatives in advance. With two teachers present, one can deliver an explanation verbally with a visual model while the other simultaneously demonstrates a physical or digital version, presenting multiple representations in real time rather than across separate sessions.
Inquiry-based and discussion-heavy methodologies benefit from co-teaching because one teacher can facilitate the discussion while the other observes, tracks participation patterns, takes notes on student reasoning, and prepares follow-up questions. This division is difficult to maintain alone and nearly impossible to document in a class of 25 or more.
Sources
- Friend, M., & Cook, L. (1992). Interactions: Collaboration Skills for School Professionals. Longman.
- Murawski, W. W., & Swanson, H. L. (2001). A meta-analysis of co-teaching research: Where are the data? Remedial and Special Education, 22(5), 258–267.
- Hang, Q., & Rabren, K. (2009). An examination of co-teaching: Perspectives and efficacy indicators. Remedial and Special Education, 30(5), 259–268.
- Friend, M. (2008). Co-Teach! A Handbook for Creating and Sustaining Effective Classroom Partnerships in Inclusive Schools. Marilyn Friend, Inc.