One of the world’s premier chemistry competitions
For four decades, the U.S. National Chemistry Olympiad has been the proving ground for America’s most talented young chemists. Sponsored by the American Chemical Society — the world’s largest scientific society — since 1984, the program reaches thousands of high-school students each year and channels the very best toward the International Chemistry Olympiad, the most prestigious chemistry competition for pre-university students anywhere.
What sets it apart is its rigor and its reach. The competition is a sequence of increasingly demanding stages, each rewarding genuine chemical understanding rather than memorization. Students who advance must master theory across the full scope of advanced chemistry and demonstrate real skill at the laboratory bench — the same combination the international competition demands.
A strong USNCO result is also a recognized marker of scientific talent for university admissions and competitive summer programs. More importantly, the preparation itself — working through years of past papers and learning to think like a research chemist — builds a foundation that lasts well beyond high school. For students aiming at selective universities, few experiences demonstrate scientific maturity as convincingly as a serious run at the National Exam — the same discipline that distinguishes strong undergraduates in chemistry.
A four-tier program, from your school to the world stage
Each stage narrows the field while raising the bar, so the students who reach the top have proven themselves repeatedly — first against their section, then the nation, and finally at a residential camp where the team is chosen. Knowing the full route, and where the real selection pressure falls, is the first step in planning a serious attempt.
Local Chemistry Olympiad
The entry point each March. High-school students register through their ACS Local Section; coordinators select nominees for the National Exam based on local results.
National Chemistry Olympiad
A rigorous three-part exam taken by more than 1,000 students each April — multiple choice, free response, and a hands-on laboratory practical — usually hosted at universities and colleges.
Study Camp
The 20 top-scoring students spend two weeks at a rigorous residential Study Camp in June. From their performance, four are selected to represent the United States.
International Chemistry Olympiad
The four U.S. competitors travel with mentors who translate the exam, inspect the laboratories, and arbitrate the scoring — the summit of the chemistry-olympiad year.
Four students. One flag. The world stage.
Every July, four U.S. competitors represent the nation at the International Chemistry Olympiad — the summit of the four-tier pathway. Team USA medals year after year; at the 2025 IChO in Dubai, all four members returned with gold, competing against 354 students from 91 countries.
Inside the National Exam
The USNCO treats the AP-level syllabus as a starting point and pushes well beyond it. The National Exam is delivered in three parts — and it is the third, the bench work, that most distinguishes the olympiad from a conventional written test. Together the three parts reward both speed and conceptual depth — and, above all, students who have practiced under genuine exam conditions rather than relying on classroom familiarity alone.
Multiple choice
Sixty questions that reward broad fluency and speed across the full syllabus — the section that quickly separates confident chemists from the rest.
Free response
Written, fully worked solutions to demanding multi-step problems — where rigorous reasoning and clear communication earn the marks.
Laboratory practical
A real experiment at the bench, judged on technique, accuracy, and analysis — mirroring the laboratory round at the International Chemistry Olympiad.
Across all three parts, the exam rewards genuine understanding over recall. The questions that decide the top of the field rarely turn on a single fact — they ask students to combine ideas, reason quantitatively under time pressure, and justify every step. Only the genuine past papers reveal how the problems are layered, how the marks are awarded, and how to budget time across the three sections — which is precisely why steady, early practice consistently beats last-minute cramming.
Build the depth the National Exam rewards
The students who advance treat past papers as a training plan, not a last-minute review. The most effective preparation is steady and structured: a clear map of the syllabus, regular timed practice on real past papers, and focused work on the question types — multi-step free response and the laboratory practical — that separate strong scorers from the rest. Starting months ahead, rather than weeks, is what turns ability into a place on the National Exam.
- A structured study plan mapped to the official syllabus
- Years of past papers worked with full answer keys
- Targeted coaching for the free-response and lab sections
Start where you need to
Rules & eligibility
Who can compete, how the four tiers work, and how students advance.
Exams & past papers
The syllabus, the three-part National Exam format, and a library of past papers.
Winners & Team USA
Team USA earned four gold medals at the 2025 IChO. See past results and honors.
Frequently asked about the USNCO
What is the U.S. National Chemistry Olympiad?
The USNCO is a multi-tiered chemistry competition for high-school students, sponsored by the American Chemical Society since 1984. It develops top young chemists and selects the four students who represent the United States at the International Chemistry Olympiad.
Who is eligible to compete?
USNCO is open to high-school students in the United States. Students selected for the international team must be U.S. citizens or permanent residents (hold a U.S. passport or green card). Students register for the Local Exam through their ACS Local Section.
How do the four tiers work?
Students begin with the Local Exam in March. Coordinators nominate top performers for the National Exam in April — taken by more than 1,000 students. The 20 highest scorers attend a Study Camp in June, where four are chosen for Team USA, who compete at the IChO in July.
What does the National Exam cover?
Three parts: multiple choice, written free response, and a laboratory practical. It spans the full advanced high-school syllabus — thermodynamics, kinetics, equilibrium, electrochemistry, and organic chemistry — rewarding conceptual depth and hands-on skill.
When can I register for the 2026 season?
Registration for the 2026 cycle opened on 6 October 2025. The Local Exam runs 27 February – 16 March 2026, followed by the National Exam (10–19 April), the Study Camp (31 May – 13 June), and the IChO (10–19 July), all via your ACS Local Section Coordinator.
How competitive is the USNCO?
Tens of thousands take Local Exams, but only the strongest advance. More than 1,000 sit the National Exam, around 20 reach the Study Camp, and just four make Team USA. Reaching the National Exam — and earning national honors — marks a student among the country’s most accomplished young chemists.
How is it different from AP Chemistry?
AP Chemistry certifies college-level coursework; the USNCO is a competition that goes beyond it. The National Exam treats the AP syllabus as a baseline, then tests greater depth, faster problem-solving, and laboratory reasoning. Strong AP students are well positioned to begin USNCO preparation.
How should I prepare?
Start early and work past papers under timed conditions — they are the best guide to the exam’s depth. Build a study plan mapped to the syllabus, drill the free-response and laboratory sections, and review answer keys carefully. For structured guidance, past papers, and coaching, contact us.