BCBA® Exam Prep: All 9 BACB Domains

The nine domains are split into two sections: Section 1 (Foundations) covers Domains A–D and tests the concepts and methodology that underpin behavior analysis as a science. Section 2 (Applications) covers Domains E–I and tests how you apply those concepts in clinical practice. Both sections appear on the same 175-question exam in interleaved order. There's no Section 1 "phase" and Section 2 "phase" on test day.

How the BCBA Exam Is Scored

Of the 175 items, 165 are scored. The other 10 are unscored "field-test" items used by the BACB to calibrate future exams; you won't know which is which while you're testing. You get four hours and you can flag and return to items. The passing score is set by the BACB per administration; in practice a score of around 400 (on a scaled 0–500) is what candidates target as a working benchmark, though the exact cut score isn't published.

How to Prepare Across All Nine Domains

The mistake most candidates make is to over-study the largest domains and under-study the smallest. Domain B and Domain G are the largest at 14% each, so they get the most attention but Domain A (5%) and Domain I (11%) are typically the most vocabulary-heavy and therefore the most rewarding to drill. Cover all nine; weight your time to the actual question distribution in the table above.

Use scenario-based practice, not just flashcards. The exam tests application, not recognition. ABA Mastery's question bank is built around 2–3 sentence scenarios with rationales for every option (correct and incorrect) so you learn the trap pattern, not just the right answer.