Written By:
BCBA, LBA
Introduction
If you’re preparing for the BCBA exam, or supporting someone who is, one of the most common questions is:
How many questions can you get wrong on the BCBA exam and still pass?
The honest answer: There isn’t a fixed number.
The BCBA exam uses a scaled scoring system, not a simple “X number correct = pass” formula. That means the number of questions you can miss and still pass varies slightly depending on the exam form.
Let’s break down what that means for aspiring BCBAs in Maryland.
How the BCBA Exam Is Scored
The BCBA exam is administered by the Behavior Analyst Certification Board (BACB). According to the BACB:
- The exam consists of 185 multiple-choice questions
- 10 of those are unscored pilot questions
- 175 questions count toward your final score
- Scores are converted to a scaled score
- A scaled score of 400 is required to pass
Because the exam uses scaled scoring, the exact number of questions you can get wrong varies by version of the test.
So… Approximately How Many Can You Miss?
While the BACB does not publish an exact number, most estimates based on pass reports suggest that candidates generally need to score around 70%–76% correct to pass.
That means you might be able to miss roughly:
- 40–50 scored questions, depending on the exam version.
However, this is only an approximation.
The scaling process accounts for slight variations in difficulty between different test forms.
Why the BACB Uses Scaled Scoring
Scaled scoring ensures fairness.
If one exam version is slightly more difficult than another, the scaled scoring system adjusts accordingly.
This means:
- You are not competing against other test-takers.
- Your score is not graded on a curve.
- You only need to meet the passing standard.
The scaled scoring model protects the integrity of the certification process.
What This Means for Candidates
Instead of asking:
“How many can I get wrong?”
It’s more helpful to ask:
“How can I consistently perform above the passing threshold?”
In our experience mentoring aspiring BCBAs in Maryland, candidates who focus on overall mastery, rather than calculating allowable mistakes, perform more confidently on exam day.
Understanding the 175 Scored Questions
Here’s a simplified breakdown:
| Component | Number of Questions |
| Total Questions | 185 |
| Unscored Pilot Questions | 10 |
| Scored Questions | 175 |
| Passing Scaled Score | 400 |
Because only 175 questions count, your margin for error is narrower than many candidates assume.
Case Example: Shifting the Mindset
A candidate in Virginia once approached the exam with the mindset of “I only need to get about 130 right.”
After failing her first attempt, she realized that guessing and aiming for the minimum wasn’t enough.
For her second attempt, she:
- Focused heavily on weak domains
- Completed 8 full-length practice exams
- Reviewed every missed question thoroughly
- Studied ethics daily
She passed comfortably, not because she knew how many she could miss, but because she increased her overall consistency.
Why Performance Varies by Domain
The BCBA exam covers multiple content areas, including:
- Measurement
- Experimental design
- Behavior change procedures
- Assessment
- Ethics and professional conduct
If you perform poorly in one domain, strong performance in others may compensate, but there’s no guarantee.
We’ve seen candidates in Maryland struggle particularly with experimental design and ethics, which often require deeper applied reasoning.
The Role of Ethics Questions
Ethics questions are heavily tested.
Even if you’re strong in skill acquisition or measurement, weak performance in ethics can impact your overall scaled score.
In supervision sessions across Maryland, we’ve noticed that candidates who dedicate weekly review time to ethics consistently perform better.
Why You Should Aim Higher Than the Passing Threshold
Because the exact margin varies slightly per exam form, aiming for “just enough” can be risky.
A safer strategy:
- Aim for consistent 80%+ on practice exams
- Focus on application-based mastery
- Strengthen weaker domains
- Build testing stamina
Candidates who consistently score above 80% in practice settings typically feel more confident on exam day.
How to Calculate Your Practice Exam Readiness
When taking mock exams:
- Calculate raw percentage correctly.
- Identify domain-specific weaknesses.
- Review missed questions deeply.
- Track improvement over time.
If your practice exam scores are fluctuating around 68%, 72%, you may be close, but more refinement is needed.
Common Mistakes Candidates Make
- Overemphasizing memorization instead of application
- Ignoring ethics
- Skipping full-length timed practice exams
- Underestimating exam endurance
- Focusing on “how many can I miss” instead of “how strong is my understanding?”
We’ve seen candidates in Virginia improve dramatically once they shifted from quantity-focused thinking to quality-focused mastery.
What Happens If You Don’t Pass?
If you fail:
- You receive a score report with performance by content area.
- You may retake the exam within your authorization window.
- You can take it up to eight times within a two-year period.
Failure is not uncommon, but strategic review usually leads to improvement.
Why This Matters to Families
Families in Maryland benefit when BCBAs are thoroughly prepared.
The rigor of the exam ensures:
- Strong understanding of ABA principles
- Ethical competence
- Clinical reasoning skills
- Effective supervision abilities
The certification process protects families by maintaining professional standards.
Conclusion
While many candidates want a precise number of questions they can get wrong on the BCBA exam and still pass, the reality is that there is no fixed number due to the scaled scoring system used by the BACB. Most estimates suggest candidates need to answer roughly 70–76% of the scored questions correctly, but this can vary slightly depending on the exam version. Rather than focusing on calculating allowable mistakes, aspiring BCBAs in Maryland should concentrate on building consistent mastery across all content areas, especially applied reasoning and ethics. Aiming well above the minimum threshold provides a safer margin and greater confidence on test day. The exam’s rigor ensures that certified BCBAs are thoroughly prepared to provide ethical, effective services to individuals with autism and related conditions, ultimately benefiting the families and communities they serve.
At Admire ABA, we are serving communities. Our certified team brings years of rigorous training and compassionate expertise to every child we support. We are committed to delivering ethical, evidence-based ABA therapy in Maryland that empowers children with autism and related conditions to thrive.
Connect with highly trained professionals dedicated to helping your child achieve meaningful progress. Contact us today!
Frequently Asked Questions
How many questions are on the BCBA exam?
The exam has 185 multiple-choice questions, but only 175 are scored. Ten are pilot questions that do not count toward your final score.
What score do you need to pass the BCBA exam?
You must achieve a scaled score of 400. Because of scaled scoring, the exact number of questions you can miss varies depending on the exam version.
Do unanswered questions count as wrong on the BCBA exam?
Yes. Any unanswered question is marked incorrect, so it’s best to answer every item, even if you’re unsure, to maximize your chances of passing.
SOURCES:
- https://www.bacb.com/examination-information/
- https://www.reddit.com/r/bcba/comments/yhzohq/what_is_the_most_you_can_get_wrong_on_the_bcba/
- https://passthebigabaexam.com/dana-dos-how-the-bacb-scores-the-bcba-exam/
- https://ns3.ucc.edu.gh/uploaded-files/E12IDB/314800/HowManyQuestionsAreOnTheBcbaExam.pdf
- https://pmc.ncbi.nlm.nih.gov/articles/PMC4711728/
