PECS for Autism: The Picture Exchange Communication System

PECS for autism (the Picture Exchange Communication System) is a structured way to teach children to communicate by handing a picture to another person to ask for what they want. Developed by Andy Bondy and Lori Frost, it is taught in six phases [1][2]. It can increase picture-based communication, but effects on speech are small and mixed.

What is PECS for autism?

PECS is a type of augmentative and alternative communication (AAC). AAC means any way of communicating that adds to or replaces speech, such as signs, picture boards, or devices that speak [4]. You can read more in our guide to AAC for autistic children.

According to its developers, PECS was created in 1985 at the Delaware Autism Program in the United States, where it was first used with autistic preschoolers [2][3]. Bondy and Frost began publishing about it in the early 1990s, and research reviews of PECS start from 1994 [5]. The approach combines teaching methods from applied behavior analysis (ABA) with ideas from the AAC field [1].

What makes PECS different is the exchange. Instead of pointing to a picture, the child picks up a picture card and hands it to a person. That person responds right away, for example by giving the snack shown on the card. The goal is for the child to start communication, not just answer questions. PECS teaches requesting first, before answering questions or commenting [1].

The 6 phases of PECS for autism

PECS is taught in a set order. The developer’s names for the phases, with a plain description, are below [2][3].

1. Phase I: How to communicate. The child learns to pick up a single picture and hand it to a partner in exchange for something they really want. At first, an adult physically helps with the exchange.
2. Phase II: Distance and persistence. The child learns to use the skill more independently: going to get their picture or their communication book, moving toward their partner, and using it with different people and places.
3. Phase III: Picture discrimination. The child learns to choose the right picture from two or more pictures.
4. Phase IV: Sentence structure. The child builds a simple sentence strip, such as “I want” plus a picture, and hands over the whole strip. Later, children may add describing words, such as colors or sizes.
5. Phase V: Responsive requesting. The child learns to answer the question “What do you want?”
6. Phase VI: Commenting. The child learns to comment in response to questions such as “What do you see?” or “What do you hear?”

Moving through the phases takes different amounts of time for different children. A 2024 systematic review found that most children in published single-case studies mastered only the first two phases. It also found that children taught Phase III were, on average, choosing from only about three pictures, which may limit how many different messages they can send [13].

How PECS differs from other AAC and speech-generating devices

AAC is a broad family. ASHA describes “unaided” AAC, such as gestures and sign language, and “aided” AAC, which uses an external tool. Aided AAC can be low-tech, such as picture cards and boards, or high-tech, such as speech-generating devices (SGDs) and tablet apps that speak a word when a button is pressed [4].

PECS is low-tech and aided. It is also a specific, manualized program, meaning it has a written step-by-step teaching protocol [4]. A picture board or communication app, by contrast, is a tool that can be taught in many different ways.

Some key differences:

• Exchange vs. pointing or pressing. PECS requires the child to physically give a card to someone, which builds in getting a partner’s attention. With a device, the voice output can be heard across a room.
• Vocabulary size. Picture books can hold many cards, but in research, children often used small sets [13]. Devices can store large vocabularies, though finding words may take navigation skills.
• Cost and durability. Cards are cheap and easy to replace. Devices cost more but can be easier to carry and expand.

Studies comparing the two are small. In a pilot randomized trial with 35 school-age autistic children, both PECS cards and a speech-generating app led to significant improvements in communication, and the two did not differ significantly [14]. A study with three preschoolers found that both PECS and an iPad could teach requesting, although the children needed more prompted practice with the iPad [15]. Many children use more than one form of AAC.

What the research says about PECS for autism

Reviews and meta-analyses

A 2010 meta-analysis of PECS studies published from 1994 to 2009 included 8 single-case studies and 3 group studies. It called PECS “promising but not yet established” for children aged 1 to 11. Children made small to moderate gains in communication, but gains in speech were small to negative. The authors also raised concerns about whether gains last and carry over to new settings [5].

A 2012 meta-analysis of single-case research also called PECS promising. The biggest effects were on functional communication (the skill PECS directly teaches). Preschool children tended to show the strongest effects, and children who moved through more phases generally had the best outcomes [6].

In the United States, the National Clearinghouse on Autism Evidence and Practice (NCAEP) review, published in 2021, listed AAC as an evidence-based practice. PECS was listed as a manualized intervention that meets evidence criteria within the AAC category [10].

Randomized trials

The largest well-known trial took place in UK schools. It included 84 autistic children with a mean age of 6.8 years. After teachers received PECS training and expert consultation, children started communication more often and used more picture symbols. But there were no increases in how often they spoke, and the gains in picture use were not kept once the active program ended [8]. A follow-up analysis of the same children found that spontaneous speech did increase and was still higher 9 months later, mostly in children who could already say a little at the start [9].

A Cochrane review of communication interventions for minimally verbal autistic children found only two trials that met its strict criteria, one of them this PECS trial. It rated the overall evidence as very low quality and concluded there was limited evidence that these interventions lead to lasting improvements [7].

Some newer studies are more positive. A small Italian study of 18 preschoolers found that PECS led to larger gains than conventional language therapy in social skills, joint attention, requesting, and starting interactions [16]. A 2026 meta-analysis of 37 randomized trials from mainland China reported a large effect of PECS on communication skills, but no significant effect on language development [17]. Results from one country’s studies may not apply everywhere.

Does PECS for autism help or hurt speech?

Many parents worry that using pictures will make their child stop trying to talk. The research is reassuring. A systematic review of AAC for autistic children found that AAC does not hold back speech, and most studies reported some increase in speech. The authors stressed that these gains were modest, so families should have realistic expectations [11]. An earlier review across developmental disabilities found no cases where speech decreased after AAC was introduced [12].

ASHA states that AAC does not reduce motivation to use speech, and can help improve it when therapy supports both speech and AAC together [4]. For PECS for autism specifically, speech gains have been small and vary between children [5][9]. The goal of PECS is communication first, whether or not speech follows.

How to start PECS for autism at home with your SLP

PECS works best as a team effort. Your child’s speech-language pathologist can assess your child, decide if PECS is a good fit, and show you how to practice each step. See our guide to speech therapy for autism for how to find and work with an SLP. You do not need to buy a course or kit to begin; ask your SLP what you need.

What you can do at home

• Start with what your child loves. PECS begins with requests, so the first pictures are usually highly wanted items, such as a favorite snack or toy [1].
• Respond right away. When your child gives you a picture, give the item quickly and say the word as you hand it over. This shows that the picture works and models speech without requiring it.
• Keep pictures within reach. A communication book or board only helps if it is available at meals, play time, car rides, and visits.
• Practice across people and places. Concerns about generalization are a common finding in PECS research [5]. Ask relatives, teachers, and therapists to use the same system.
• Keep going after therapy ends. In the large school trial, gains in picture use faded once support stopped [8]. Regular use at home helps.
• Grow the vocabulary. Ask your SLP how to add more pictures and new ways to communicate so your child is not limited to a few requests [13].

Pictures used for PECS can also support other visual tools, such as visual schedules.

Limits of PECS for autism

• Mostly requesting. Research shows PECS reliably increases requests for objects. Requests for social reasons, such as sharing or chatting, increased less [9].
• Gains may not last. Several studies found gains faded or did not generalize without ongoing support [5][8].
• Evidence quality. Many studies are small or single-case designs, and the Cochrane review rated trial evidence as very low quality [7].
• Behavioral teaching methods. PECS draws on ABA principles [1]. Some families and autistic adults have concerns about ABA-based approaches. You can ask how prompts and rewards will be used, and read our balanced guide to ABA therapy.
• Not one size fits all. PECS for autism is one option. Some children do better with a device, signs, or a mix. A child’s right to communicate does not depend on progressing through a program.

When to talk to a professional

Talk to your child’s doctor or an SLP if your child is not using words or gestures to communicate, if communication frustration leads to distress, or if your child has been using PECS for a while without progress. An SLP can also check whether your child would benefit from a different or additional form of AAC. ASHA notes that there are no prerequisites for AAC, so you do not need to wait for a certain age or skill level to ask [4].

Frequently asked questions

Will PECS stop my child from learning to talk?

Research does not show that. Systematic reviews of AAC, including picture-based systems like PECS, found that AAC does not hold back speech, and most studies reported small increases in speech. ASHA says AAC does not reduce a child’s motivation to talk. Speech gains from PECS itself have been small and vary a lot between children, so keep realistic expectations and keep supporting speech too.

What age can a child start PECS?

There is no set starting age. Studies have included children from about 1 to 11 years old, and one meta-analysis found preschool children tended to show the strongest effects. ASHA says there are no prerequisites for AAC, so a child does not need to show certain skills before starting. Your speech-language pathologist can help decide whether PECS fits your child now.

Is PECS better than a speech-generating device or tablet app?

Not clearly. A small randomized trial of 35 school-age autistic children found both PECS cards and a speech-generating app improved communication, with no significant difference between them. Another small study found both could teach requesting. The best choice depends on your child’s motor skills, interests, and needs. Many children use more than one type of AAC over time.

How long does each PECS phase take?

It varies widely. A 2024 systematic review of PECS studies found that most participants mastered only the first two phases, and the time needed for Phases I, II, and IV varied the most. Some children move quickly, while others need much longer or may do better with a different system. Your SLP should track progress and adjust the plan rather than follow a fixed timeline.

References

1. Bondy AS, Frost LA. The picture exchange communication system. Semin Speech Lang. 1998;19(4):373-388. doi:10.1055/s-2008-1064055 Link
2. Pyramid Educational Consultants. Picture Exchange Communication System (PECS): overview of the approach and its six phases (developer’s description). Accessed October 2026. Link
3. Center on Secondary Education for Students with ASD (CSESA), FPG Child Development Institute, UNC Chapel Hill. Picture Exchange Communication System (PECS): Overview (evidence-based practice brief). Link
4. American Speech-Language-Hearing Association (ASHA). Augmentative and Alternative Communication. Practice Portal. Accessed October 2026. Link
5. Flippin M, Reszka S, Watson LR. Effectiveness of the Picture Exchange Communication System (PECS) on communication and speech for children with autism spectrum disorders: a meta-analysis. Am J Speech Lang Pathol. 2010;19(2):178-195. doi:10.1044/1058-0360(2010/09-0022) Link
6. Ganz JB, Davis JL, Lund EM, Goodwyn FD, Simpson RL. Meta-analysis of PECS with individuals with ASD: investigation of targeted versus non-targeted outcomes, participant characteristics, and implementation phase. Res Dev Disabil. 2012;33(2):406-418. doi:10.1016/j.ridd.2011.09.023 Link
7. Brignell A, Chenausky KV, Song H, Zhu J, Suo C, Morgan AT. Communication interventions for autism spectrum disorder in minimally verbal children. Cochrane Database Syst Rev. 2018;11(11):CD012324. doi:10.1002/14651858.CD012324.pub2 Link
8. Howlin P, Gordon RK, Pasco G, Wade A, Charman T. The effectiveness of Picture Exchange Communication System (PECS) training for teachers of children with autism: a pragmatic, group randomised controlled trial. J Child Psychol Psychiatry. 2007;48(5):473-481. doi:10.1111/j.1469-7610.2006.01707.x Link
9. Gordon K, Pasco G, McElduff F, Wade A, Howlin P, Charman T. A communication-based intervention for nonverbal children with autism: what changes? Who benefits? J Consult Clin Psychol. 2011;79(4):447-457. doi:10.1037/a0024379 Link
10. Hume K, Steinbrenner JR, Odom SL, et al. Evidence-based practices for children, youth, and young adults with autism: third generation review. J Autism Dev Disord. 2021;51(11):4013-4032. doi:10.1007/s10803-020-04844-2 Link
11. Schlosser RW, Wendt O. Effects of augmentative and alternative communication intervention on speech production in children with autism: a systematic review. Am J Speech Lang Pathol. 2008;17(3):212-230. doi:10.1044/1058-0360(2008/021) Link
12. Millar DC, Light JC, Schlosser RW. The impact of augmentative and alternative communication intervention on the speech production of individuals with developmental disabilities: a research review. J Speech Lang Hear Res. 2006;49(2):248-264. doi:10.1044/1092-4388(2006/021) Link
13. Forbes HJ, Travers JC, Vickers Johnson J. A systematic review of acquisition and mastery of skills taught using the Picture Exchange Communication System. Augment Altern Commun. 2024;40(2):100-114. doi:10.1080/07434618.2024.2302154 Link
14. Gilroy SP, Leader G, McCleery JP. A pilot community-based randomized comparison of speech generating devices and the picture exchange communication system for children diagnosed with autism spectrum disorder. Autism Res. 2018;11(12):1701-1711. doi:10.1002/aur.2025 Link
15. Agius MM, Vance M. A comparison of PECS and iPad to teach requesting to pre-schoolers with autistic spectrum disorders. Augment Altern Commun. 2016;32(1):58-68. doi:10.3109/07434618.2015.1108363 Link
16. Lerna A, Esposito D, Conson M, Russo L, Massagli A. Social-communicative effects of the Picture Exchange Communication System (PECS) in autism spectrum disorders. Int J Lang Commun Disord. 2012;47(5):609-617. doi:10.1111/j.1460-6984.2012.00172.x Link
17. Huang H, Zhu H, Tang H, et al. Efficacy of the Picture Exchange Communication System for children with autism in Mainland China: a systematic review and meta-analysis of randomized controlled trials. Res Dev Disabil. 2026;168:105190. doi:10.1016/j.ridd.2025.105190 Link

Professional review: this guide is waiting for review by a qualified clinician. It was written and checked against the published sources listed above. How we check our guides.

This guide is general education, not medical advice. Always talk to your child’s doctor or care team. Last checked: October 2026.