CAS Practice Test

The Certified Autism Specialist credential, awarded by the International Board of Credentialing and Continuing Education Standards, is for professionals who work with or support people with autism. This page gives you free practice sets sorted by competency area, worked questions with explanations, a study plan, and plain answers about exam format, scoring and eligibility.

CAS Exam at a Glance

What changed for CAS in 2026

• Oct 27, 2026: Renewal changed to $199 every 2 years (previously $199 every two years).^[4]
• Oct 27, 2026: Delivery changed to Online proctoring (previously Online exam, included in the application price).^[1]
• Oct 27, 2026: Time limit (program completion) changed to 60 days (previously 60 days to finish coursework and exam).^[2]
• Oct 27, 2026: Eligibility (experience) changed to 2 years experience (previously 2 years' experience supporting autistic individuals).^[4]
• Oct 27, 2026: Eligibility (continuing education) changed to 14 CE hours (previously 14 autism CE hours within the last two years).^[4]

What the CAS is and how it works

According to International Board of Credentialing and Continuing Education Standards, “The CAS Autism Competency Exam has approximately 60 multiple choice questions. A passing score of 80% is required..”^[1]

The Certified Autism Specialist credential is awarded by the International Board of Credentialing and Continuing Education Standards (IBCCES). The CAS Autism Competency Exam is administered online via an online proctoring system. It has approximately 60 multiple-choice questions, and candidates are given a total of 90 minutes. A passing score of 80% is required.

Eligibility is separate from the exam. Applicants need 14 hours of continuing education that directly relates to autism, earned within the last 2 years. They also need 2 years of experience working in a field that treats or supports individuals with autism, plus a graduate-level degree. The degree requirement is waived for applicants with a bachelor's degree and at least 10 years of experience.

After the board approves your application, you get immediate access to a digital certificate and badge, and your certification packet is prepared within 2-3 weeks. The credential is valid for 2 years, and renewal costs $199 every 2 years. If you take the IBCCES training program, the coursework and final exam must be completed within 60 days.

We have not listed an exam fee or a retake policy because they are not among the facts we verified. Check ibcces.org for current rules before you apply or book your exam.

CAS content outline and where to practise each area

The content areas below are copied from the official CAS content outline published by International Board of Credentialing and Continuing Education Standards, with the share of the exam each area carries. The right-hand column shows which of our practice sets covers it.

Worked examples: how to reason through CAS questions

These are practice questions written for this site, not questions from the real exam. Each explanation shows why the right answer is right and why the others are wrong.

Example 1

Question: Which type of curriculum modification involves simplifying the complexity or difficulty of content while maintaining access to the same general education curriculum?

1. Curriculum compacting
2. Accommodations
3. Modifications
4. Enrichment

Answer: C. Modifications

Explanation:

The answer is Modifications. A modification changes what a student is expected to learn or show, for example by reducing the complexity or amount of content, while the student stays in the same general education curriculum. Accommodations are wrong because they change how a student reaches the same content, not the content itself. Curriculum compacting is wrong because it condenses material a student has already mastered so they can move faster, which is not simplification. Enrichment is wrong because it adds depth or extension rather than lowering difficulty. Rule to remember: accommodations change the route, modifications change the target. When a question mentions simplified content or reduced expectations, think modification.

Example 2

Question: Why is early identification of autism important?

1. It prevents autism from developing
2. It allows for early intervention and improved outcomes
3. It ensures a child will outgrow autism
4. It is only necessary for children with severe symptoms

Answer: B. It allows for early intervention and improved outcomes

Explanation:

The answer is that early identification allows for early intervention and improved outcomes. Spotting differences sooner lets families and professionals begin supports while a child is developing quickly. It does not prevent autism from developing, because identification describes what is already present and does not change the underlying condition. It does not ensure a child will outgrow autism, since no such outcome can be promised. It is not only for children with severe symptoms, because supports are useful across a wide range of needs. Rule to remember: identification is the doorway to support, and options that promise prevention or a cure are almost always wrong.

Example 3

Question: How do early intervention services help children with autism?

1. They have no effect on autism
2. They help improve communication and social skills
3. They are only useful for children with physical disabilities
4. They replace the need for a diagnosis

Answer: B. They help improve communication and social skills

Explanation:

The answer is that early intervention services help improve communication and social skills. Services such as speech and occupational therapy target the skills a young child is building, which supports overall development. The claim that they have no effect is wrong because support is intended to make a difference. The claim that they are only useful for physical disabilities is wrong because they address communication, social and developmental needs. The claim that they replace the need for a diagnosis is wrong because services and diagnosis do different jobs and one does not stand in for the other. Rule to remember: intervention builds skills, and absolute words such as only or replace are warning signs.

How to use these practice tests

Start with the official IBCCES material so you know the exam's content areas and format, then use these sets to find where you are weak.

1. Take the Autism Overview set first. It carries the largest share of the exam, so gaps there cost the most.
2. Work through the behavior, sensory, social skills and parent communication sets next, one at a time. After each, write down every question you missed and the reason in a single sentence.
3. Use the early childhood identification set and the educational and transition planning set to practise program development reasoning.
4. For areas with no set on this page, such as medical and health or environment, read the official outline and make your own short notes.
5. Before test day, do a timed run of mixed questions. The real exam is online proctored, so practise on the same device and in the same quiet space you will use.

Our questions are written by us and are not real exam questions. Treat them as a way to test your reasoning, not to predict what you will see.

Sources & last verified

1. International Board of Credentialing and Continuing Education Standards — number of questions, time limit, passing score, delivery (official source). “The CAS Autism Competency Exam has approximately 60 multiple choice questions. A passing score of 80% is required..” Verified Oct 28, 2026.
2. International Board of Credentialing and Continuing Education Standards — time limit, score release (official source). “You will have to complete the coursework and final exam within 60 days.” Verified Oct 27, 2026.
3. International Board of Credentialing and Continuing Education Standards — validity (official source). “Credentials are valid for two years.” Verified Oct 27, 2026.
4. International Board of Credentialing and Continuing Education Standards — renewal, eligibility (official source). “Renewal fee: $199 every two years” Verified Oct 27, 2026.

How we verify: editorial & fact-checking policy. Report an error: contact us.