The Picture Exchange Communication System (PECS) is a structured form of augmentative and alternative communication (AAC) in which a learner exchanges a picture for a desired item or activity. For autistic children with limited speech, the evidence shows small to moderate gains in functional communication, with weaker and less consistent effects on spoken language. PECS is best understood as one well-defined option within a broader AAC toolkit, not a stand-alone solution.
Key takeaways
- PECS teaches initiation of communication through a six-phase protocol, starting with a single picture exchange and building towards sentence structure and commenting.
- The strongest meta-analysis to date describes PECS as "promising but not yet established", with small-to-moderate communication gains and small-to-negative gains in speech ().
- Maintenance and generalisation beyond the training setting are recognised limitations and should be planned for explicitly.
- PECS sits alongside other AAC such as speech-generating devices, paper-based boards and key word sign; system selection should be individualised by a speech pathologist ().
- A speech pathologist should match the AAC system to the individual; no single approach suits everyone ().
What is PECS and who developed it?
PECS is a picture-based AAC approach developed in the United States in 1985 by Andy Bondy, PhD, and Lori Frost, MS, CCC-SLP (). Unlike many communication programs that begin by teaching a child to respond, PECS begins by teaching the child to initiate — to hand a picture to a communication partner in exchange for something they want. This focus on spontaneous, functional requesting is a defining feature and a reason it is often introduced early for autistic children with emerging communication.
PECS is an aided AAC system: it relies on external materials (pictures and a communication book) rather than the body alone. Speech Pathology Australia groups AAC into aided systems (paper-based systems and speech-generating devices) and informal or unaided methods such as gestures and key word sign, noting that a speech pathologist can help decide which type is right for an individual ().
What are the six phases of PECS?
The protocol is delivered in a fixed sequence, with each phase building on the last ().
Vocabulary and language concepts (attributes, verbs, prepositions) are expanded across phases. Importantly, the sequence is a teaching structure, not a developmental ceiling — many learners move on to other AAC, spoken language, or a combination.
What does the evidence actually show?
The most cited synthesis is a meta-analysis by Flippin, Reszka and Watson, published in the American Journal of Speech-Language Pathology in 2010. It pooled 8 single-subject experiments (18 participants) and 3 group studies (95 PECS participants), in children with autism aged roughly 1–11 years. The authors reported small to moderate gains in communication and small to negative gains in speech, and concluded that PECS is "a promising but not yet established evidence-based intervention" (; ).
Two practical messages follow for clinicians:
- Set communication-first expectations. The evidence supports PECS for building functional requesting and broader communicative behaviour. It does not support promising families that PECS will produce speech; spoken-language effects were the weakest finding.
- Plan for maintenance and generalisation. The same review flagged concerns about whether gains transfer to new settings and are maintained over time. These are not reasons to avoid PECS — they are reasons to embed it across natural routines and partners from the outset.
It is also worth noting what the evidence does not show: the meta-analysis found speech effects that were small to negative, but this reflects limited benefit for speech rather than evidence that PECS harms spoken-language development (). Introducing a functional way to communicate early remains the priority, with spoken language supported alongside where appropriate.
Where does PECS fit among AAC options?
PECS is one tool among several. A speech pathologist may consider:
- Paper-based systems — communication books and boards with symbols, pictures or words.
- Speech-generating devices (SGDs) — purpose-built devices, or apps on tablets, that produce voice output.
- Key word sign and gestures — unaided methods that need no equipment.
No single system suits everyone, and many people use a combination across contexts (). The choice depends on the child's motor and visual skills, motivation, communication partners and environments — which is why an individualised assessment, rather than a default to any one method, is the appropriate starting point. Our can help families weigh these options.
Strengths and limitations of PECS
Strengths
- Teaches initiation and spontaneous requesting from the first phase.
- Low-tech, portable and low-cost to begin.
- Highly structured protocol that is straightforward for partners and educators to learn.
- Reasonable evidence for functional communication gains in autistic children.
Limitations
- Spoken-language effects are weak and inconsistent.
- Maintenance and generalisation require deliberate planning.
- Some learners benefit from moving to higher-tech AAC as needs grow.
- Fidelity matters; benefits depend on the protocol being delivered as designed.
How does PECS align with NDIS goals?
Under the NDIS, supports are funded where they are reasonable and necessary and connected to a participant's goals. For a child working towards communicating wants and needs, participating at school, or reducing the frustration that can accompany limited communication, an AAC approach such as PECS can be a clear fit when a speech pathologist's assessment supports it. The relevant funded activities typically include the speech pathology assessment, therapy, system set-up, and training for parents, carers and educators — communication is a shared responsibility, not a device handed over in isolation.
Because "reasonable and necessary" decisions are individualised, the role of the clinician is to document the link between the proposed AAC support and the participant's stated goals, the expected functional outcomes, and how progress will be reviewed. PECS should be framed honestly: as an evidence-informed method to build functional communication, not as a guaranteed pathway to speech.
Evidence at a glance
Frequently asked questions
Does PECS stop a child from learning to talk?
The meta-analysis evidence shows PECS has small-to-negative effects on speech — meaning limited benefit for spoken language, not evidence that it suppresses speech (). PECS is best offered as a way to communicate now, with spoken language supported separately where appropriate. A speech pathologist can advise on the right combination for an individual.
Is PECS evidence-based?
It is evidence-informed. The leading meta-analysis describes PECS as "promising but not yet established", with measurable communication gains but limitations around speech, maintenance and generalisation (). It is a reasonable option for many autistic children when matched to the individual.
How is PECS different from a communication app or device?
PECS is a low-tech, picture-exchange protocol. Speech-generating devices and tablet apps add voice output and larger vocabularies. Neither is universally better; the right choice depends on the individual's skills, goals and environments, assessed by a speech pathologist ().
Can NDIS funding cover PECS and AAC support?
Where AAC is reasonable and necessary and tied to a participant's communication goals, the assessment, therapy, set-up and partner training are the kinds of supports a speech pathologist would seek to include. Because decisions are individualised, the clinician's documentation of goal alignment and expected outcomes is central.
Who should deliver and oversee a PECS program?
A speech pathologist should lead assessment and planning, train communication partners, and monitor fidelity and progress, adjusting the system as the child's needs change. Our works with families, schools and support teams to keep communication consistent across settings.
If you would like to discuss whether PECS or another AAC approach suits a child or participant, . Speak with Align Network's speech pathology and occupational therapy team.
Contact Align Network today
Contact Align Network for specialist behaviour support, plan management, or allied health coordination.