USABO Timeline & Calendar: Every Stage From Registration to National Finals

The USABO sequence never changes; the exact dates shift a little every year. If you understand the sequence and plan backward from the February Open Exam, you will never be caught out — and you will avoid the one fatal mistake, which is missing the registration window in the autumn.

⚠️ The stages below are stable; the specific dates are not. Registration deadlines and the fee change every cycle, so confirm the exact dates for your year on the official sources — cee.org and usabo-trc.org — before planning around them. Dates shown are typical of recent cycles.

The sequence, in order

How to plan your study around it

Work backward from the February Open:

• Six months out (previous autumn): begin structured preparation — Campbell coverage plus the areas AP underweights (plant/animal physiology, ethology, biosystematics). This is also when school registration happens, so handle both together.
• ~Two months out (December–January): shift to past-paper saturation and timed Open simulations.
• February: the Open Exam. Arrive with a full preparation cycle behind you.
• If you advance: the spring Semifinal is a different, harder exam (longer, free-response, data interpretation) — the weeks between the Open and Semifinal are for stepping up to that depth.
• June onward: for finalists, the National Finals include a practical/lab component; the very top form Team USA for the July IBO.

A student who starts in the autumn arrives at the February Open with real depth. A student who starts in January is racing the clock — it can be done, but it is the harder road.

The eligibility line on the calendar

One thing that intersects the timeline and trips people up: the Open Exam is open to any student at a registered US school, but advancing past the Open (Semifinal, Finals, Team USA) requires US citizenship or permanent residency. So an international student at a US school can take the February Open regardless of citizenship, but the spring Semifinal and beyond are citizenship-gated. (Details in our international-students guide.)

Get a dated calendar for your cycle

If you would like a study calendar dated to the current cycle — working backward from this year's confirmed Open date, with a week-by-week plan — message us on WhatsApp at +91 88264 44334 and we will send you one built around the official dates for your year.

Related reading: How to Register for USABO · USABO for International Students · Our USABO coaching program