Omega LearnHow to Prepare for the USA Biology Olympiad (USABO)
HighWhat is the USABO?
The USA Biology Olympiad (USABO) is the premier biology competition for U.S. high school students, run by the Center for Excellence in Education (CEE). It begins with the Open Exam, a 50-minute, 50-question multiple-choice test taken online in February. The top scorers advance to the 120-minute Semifinal Exam in March, which adds short-answer and multiple true/false questions. The top 20 students earn a place at the National Finals, where four gold medalists are chosen to represent the USA at the International Biology Olympiad (IBO).
Format
Two online rounds: a 50-minute, 50-question multiple-choice Open Exam, then a 120-minute Semifinal Exam mixing multiple choice, multiple true/false, and short-answer questions.
Who can enter
Any student in grades 9-12, including home-schooled students. To advance past the Open Exam, students must be U.S. citizens or legal permanent residents (green card holders).
When & how
The Open Exam is held in February and the Semifinal in March, both proctored online at a registered school or authorized USABO center. Students register through their school with CEE.
How to advance
Top Open Exam scorers reach the Semifinal; the top 20 join the residential National Finals training program. Four gold medalists represent the USA at the International Biology Olympiad (IBO).
Official Information
USA Biology Olympiad (CEE) home
The official USABO site, run by the Center for Excellence in Education (CEE), with registration, calendar, and program news.
View โUSABO: About the Exams
The official breakdown of the Open Exam, Semifinal Exam, and National Finals, including format and question types.
View โUSABO: Guidelines and Eligibility
Official eligibility rules covering grade level, citizenship and residency, age, and graduation-year requirements.
View โUSABO: Rules and Regulations
The official rules for proctoring, permitted materials, and conduct during the online Open and Semifinal exams.
View โUSA Biolympiad overview
A Wikipedia overview of the USA Biology Olympiad, its structure, and its history at the International Biology Olympiad.
View โPractice Tests
Past USABO exams are the highest-value practice available. The format and pacing barely change year to year, so take each paper under real timed conditions, then review every question you missed against the official answer key.
Official USABO past exams (Open & Semifinal)
The CEE archive of past Open and Semifinal exams, the single best practice source with authentic format and pacing.
View โUSABO Student Corner
The official student hub linking past papers, answer keys, and study guidance for both exam rounds.
View โUSABO past papers with worked solutions
A downloadable archive of Open Exam and Semifinal past papers with worked solutions from Biolympiads Academy.
View โIBO past exams
International Biology Olympiad theory and practical exams, the next step in difficulty after the USABO.
View โPaid Courses & Classes
Biolympiads Academy Training Camps
Live USABO problem-solving camps and video courses taught by USABO semifinalists and IBO medalists, built around Campbell.
View โFLEX Biology Olympiad Prep Program
A structured biology olympiad prep program that drills the reasoning and question styles appearing on the USABO exams.
View โBaology Prep
A USABO-focused biology course led by Biolympiad finalists and Harvard-educated instructors.
View โCerebrum Biology Academy
USABO and IBO preparation with structured courses, past-paper practice, and cutoff and results tracking.
View โIvyMax USABO Program
Guided USABO preparation with a curriculum, practice, and mentorship for students targeting the Semifinal round.
View โSpringLight Education USABO
Biology competition preparation with a track record of Open Exam and Semifinal qualifiers.
View โ