What Is the Picture Exchange Communication System in ABA Therapy?
The Picture Exchange Communication System (PECS) is an augmentative and alternative communication (AAC) system that teaches communication through the physical exchange of picture cards. A learner picks up a picture of a desired item, hands it to a communication partner, and receives the item in return. PECS is structured as a six-phase training protocol that begins with simple single-picture requests and progresses through sentence structure, commenting, and answering questions. The system was developed in 1985 by Andy Bondy, PhD, and Lori Frost, MS, CCC-SLP, at the Delaware Autism Program, and is now used worldwide with learners across age ranges and diagnostic categories. The training protocol is rooted in the principles of Applied Behavior Analysis (ABA), particularly expressive communication theory and operant learning.
According to the Indiana Resource Center for Autism at Indiana University Bloomington, PECS was designed for early nonverbal symbolic communication training. It is not a program designed to teach speech directly, although some learners begin to use spoken speech spontaneously while enrolled in PECS. PECS training takes place during typical activities in the natural settings of the classroom and home, and the program uses behavior-analytic teaching strategies including chaining, prompting, modeling, and environmental engineering.
PECS is organized into six phases that build on each other. Phase I teaches the basic exchange: when a learner sees a preferred item, they pick up the corresponding picture card and hand it to a communication partner in exchange for the item. Phase II builds distance and persistence, with the learner moving across the room and to different partners to make exchanges. Phase III introduces picture discrimination, requiring the learner to choose between multiple pictures to request the desired item. Phase IV introduces sentence structure with the carrier phrase “I want.” Phase V teaches responding to the question “What do you want?” Phase VI introduces commenting in response to other questions like “What do you see?” and “What do you have?”
One of the defining features of PECS is that it teaches initiation. Many other communication systems require an adult to start an interaction (asking a question, presenting a prompt) and the learner to respond. PECS reverses this: the learner is the one who starts the interaction, by handing a picture to someone. This focus on initiation matters because it builds the learner’s active communicative behavior rather than a passive responding repertoire.
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Examples of PECS in ABA Therapy
Example 1: Phase I with a nonspeaking three-year-old
A behavior technician is working with a three-year-old client who is nonspeaking and has been using crying and reaching to indicate desired items. A behavior analyst has assessed the learner as a good candidate for PECS and the team begins Phase I training. The technician identifies a strong reinforcer (juice) and uses a second adult as a physical prompter to guide the learner’s hand to pick up a picture of juice and hand it to the technician. As soon as the picture is exchanged, the technician hands over the juice. The team runs many exchanges throughout the day, varying items and partners. Within a few weeks, the learner is independently picking up pictures and exchanging them without physical prompting. This is the foundation for nonspeaking learners to start communicating. For more on supporting nonspeaking learners, see our blog on what is nonverbal autism: dispelling the myths.
Example 2: Moving from Phase III to sentence building
A behavior technician is working with a six-year-old client who has mastered the first three PECS phases and is now requesting reliably from a communication book containing many pictures. The behavior analyst moves the program into Phase IV, where the learner adds the carrier phrase “I want” to each request. The technician teaches the learner to first attach the “I want” picture to a sentence strip, then attach the picture of the desired item, and hand the full sentence strip to the partner. Over a few weeks, the learner is building two-card sentences independently. This phase prepares the learner for more complex communication as the system continues to develop.
Example 3: Family-implemented PECS at home
A behavior analyst coaches a family on how to use PECS at home with their five-year-old client. The therapist working with the family helps the parents set up the home environment so the learner has frequent opportunities to make requests: snacks visible but out of reach, preferred toys in clear bins the learner can’t open on her own, and a communication book available in every room. The parents learn to wait briefly for the learner to initiate an exchange, prompt as needed using a second adult, and deliver the requested item immediately when the picture is handed over. The system carries over from clinic to home with consistent results, and the learner’s spontaneous communication grows substantially over months of practice.
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Why Is PECS Important in ABA?
PECS matters because it gives nonspeaking and minimally speaking learners a structured, accessible way to communicate. A learner who can pick up a picture and hand it to someone can express needs, preferences, and ideas without depending on spoken language, sign language, or technology that requires fine motor or technological fluency. The barrier to entry is low: the learner needs to be an intentional communicator who has preferences and can pick up and release a picture card. From there, the program builds systematically toward more complex communication.
PECS has accumulated substantial research support over its history. Studies have demonstrated that learners across age ranges and cognitive profiles can acquire PECS reliably, and that PECS acquisition is associated with concurrent improvements in spoken language for some learners, reductions in interfering behavior that may have been serving communicative functions, and increases in social-communicative behavior. PECS is also often integrated into functional communication training programs, where the goal is to replace interfering behavior with a more appropriate communicative response. For many nonspeaking learners, PECS is the modality that makes FCT possible.
The system’s focus on initiation is one of its most important features. Many learners with autism have stronger responding repertoires than initiating repertoires; they can answer questions but rarely start interactions on their own. PECS directly targets initiation by structuring the entire program around the learner’s spontaneous requests. The learner is the active party in every PECS exchange, which builds their sense of agency and their everyday habit of starting communication.
PECS also has limitations worth understanding. The program is structured and protocol-driven, which means it requires formal training (typically a two-day workshop) to implement with fidelity. Behavior technicians, therapists, classroom teachers, and parents who haven’t been trained may use picture exchange in ways that don’t follow the actual PECS protocol. The system can also be limited by the number and complexity of pictures available, which is one reason many learners eventually transition from PECS to speech-generating devices or other AAC. Starting PECS as early as possible tends to produce the strongest outcomes. For more on the early intervention timing, read our blog on 5 benefits of early intervention.
PECS isn’t the only AAC system, and it’s not always the right fit. Some learners do better with speech-generating devices from the start; others may use sign language; others may use a combination of modalities. The behavior analyst, often in consultation with a speech-language pathologist, considers what fits the learner’s current abilities, the environments they’ll use the system in, and the family’s preferences. PECS is one strong option among several, particularly for early communication learners.
FAQs About the Picture Exchange Communication System
Will using PECS keep my child from learning to talk?
No, and this concern has been studied for decades. Research has consistently shown that using PECS doesn’t delay or interfere with the development of spoken speech. For many learners, PECS actually supports vocal development by giving them a successful experience with communication that motivates further attempts. Some learners enrolled in PECS begin to use spoken speech spontaneously alongside their picture exchanges. Whether spoken speech develops depends on many factors specific to the learner, but using PECS isn’t one of the things that holds it back.
Who can be a candidate for PECS?
PECS isn’t limited by age. Toddlers, school-age children, teens, and adults have all successfully used PECS. The main candidacy criteria are that the learner is an intentional communicator (aware of the need to communicate a message to someone) and has identifiable preferences that can motivate the exchanges. Picture discrimination ability isn’t required at the start, since Phase I uses only one picture at a time. Learners who are minimally speaking, primarily echolalic, or have limited spoken vocabulary can also benefit from PECS in some cases.
How long does it take to complete PECS training?
The full six-phase program may take several months or several years to complete, depending on the learner. Phase I acquisition (the basic exchange) tends to happen relatively quickly, often within a few weeks of consistent practice. Later phases involving sentence structure and commenting take longer. The behavior analyst monitors progress and advances through phases when the learner meets the criteria for each phase, rather than on a fixed timeline.
Does PECS require special training to implement?
Yes. PECS is a structured protocol with specific procedures for each phase, and implementing it as designed typically requires a two-day training workshop offered by Pyramid Educational Consultants or a certified trainer. Speech-language pathologists, behavior analysts, behavior technicians, classroom teachers, parents, and other team members can all attend the training. Picture exchange used without the formal PECS protocol can still be useful, but it isn’t the same as the PECS program and may not produce the same outcomes documented in PECS research.
Is PECS still used now that AAC devices and tablets are widely available?
Yes, PECS continues to be widely used, sometimes alongside or as a stepping stone toward speech-generating devices. PECS has some practical advantages: the materials are inexpensive, easy to repair or replace, work without batteries or wireless connections, and can be implemented in any environment without technology concerns. For some learners, PECS is the long-term communication modality; for others, PECS is the foundation that prepares them to transition to a digital AAC system later. The behavior analyst and the family decide what fits the learner’s needs and goals best.
Key Takeaways About the Picture Exchange Communication System
- The Picture Exchange Communication System (PECS) is an AAC system that teaches communication through physical exchange of picture cards, developed by Bondy and Frost in 1985.
- PECS is rooted in Applied Behavior Analysis principles and uses techniques like chaining, prompting, modeling, and environmental engineering across a six-phase protocol.
- The six phases progress from single-picture exchanges through discrimination, sentence structure, responding to questions, and commenting.
- PECS is designed for nonspeaking and minimally speaking learners, but it doesn’t require picture discrimination skills at the start and isn’t limited by age.
- Research has consistently shown that PECS doesn’t delay spoken speech and may support its development for some learners.
- PECS implementation requires formal training to follow the protocol with fidelity; behavior analysts, therapists, behavior technicians, teachers, and families all benefit from learning the program.
