Rules, eligibility & the four-tier pathway
The U.S. National Chemistry Olympiad runs through four stages, from the Local Exam to the International Chemistry Olympiad. This page explains who can compete, how students advance and the ACS calendar for the 2027 season.
Who can compete, and how to enter
The USNCO is open to U.S. high-school students, and the entry point is genuinely open: any eligible student can sit the Local Chemistry Olympiad each March. No invitation, ranking, or prior result is required to begin. The field narrows on the strength of exam scores, not on who you know.
Entry runs through the American Chemical Society’s network of Local Sections. You register for the Local Exam through your ACS Local Section Coordinator, who organizes the exam in your region, supervises it, and nominates the top scorers for the National Exam. If you are unsure which Local Section covers your school, your chemistry teacher or the ACS Local Section directory can point you to the right coordinator.
Citizenship matters at the National Exam stage: students who are neither U.S. citizens nor U.S. permanent residents may take the Local Exam, but cannot be nominated for the National Exam. Other ACS age, school and nomination requirements also apply.
- U.S. high-school students of any grade level
- No invitation needed to start the Local Exam
- Register through your ACS Local Section Coordinator
- Advancement is decided by exam scores alone
- U.S. citizenship or permanent residency is required for National Exam nomination
- One nationally administered set of exams, sat under supervision
The four tiers in detail
Each tier is harder than the last, and each one selects the students who continue. Together they form a single ladder from the local classroom to the international stage.
Local Chemistry Olympiad
The open entry point. Students register through their ACS Local Section and sit the Local Exam in their region each March. Coordinators score the papers and nominate their top performers to advance to the National Exam.
National Chemistry Olympiad
A three-part national exam taken by more than 1,000 nominated students each April, usually hosted at universities and colleges. It combines multiple-choice, written free-response, and a laboratory practical to identify the top 20.
Study Camp
The 20 highest scorers spend two weeks at a residential camp in June, training intensively in advanced theory and laboratory work. From this group, four students are chosen to represent the United States as Team USA.
International Chemistry Olympiad
The four U.S. students compete internationally each July, supported by mentors who translate the exam, inspect the laboratories, and arbitrate the scoring. The IChO is the summit of the USNCO pathway.
How students advance, tier to tier
Advancement is earned at every stage, and the rule is the same throughout: results decide who continues. At the local level, each ACS Local Section nominates its strongest scorers for the National Exam, so the size of the national field reflects performance across the country rather than a fixed quota per school.
The National Exam is where the field narrows sharply. Its three parts together rank the nominated students, and the 20 highest scorers nationwide earn places at the June Study Camp. At camp, two weeks of theory and laboratory training culminate in the selection of four students for Team USA, who go on to the International Chemistry Olympiad in July.
Recognition does not begin only at the top. The National Exam carries national honors that mark out strong performances well beyond the final four, giving many students a credential that reflects how far they advanced.
The 20 highest scorers on the National Exam, who advance to the June Study Camp and compete for the four Team USA places.
Awarded to students whose National Exam results place them among the strongest performers in the country.
Awarded to students who perform strongly on the National Exam, recognizing a result that stands out nationwide.
Key dates for the 2027 season
ACS lists student registration opening on 1 November 2026, the 2027 Local Exam on 28 February–2 March and the National Exam on 16–18 April. Contact your Local Section Coordinator for local arrangements.
The single most important step is registering with your Local Section in good time, so you are entered for the Local Exam window. Everything that follows depends on that first exam.
Register through your ACS Local Section Coordinator.
Sat in your region during the local exam window.
Three-part exam for nominated students.
Two-week residential camp for the top 20.
Team USA competes on the international stage.
Competition FAQ
Eligible high-school students enter through their ACS Local Section. Students who are neither U.S. citizens nor U.S. permanent residents may take the Local Exam, but cannot be nominated for the National Exam. Confirm other eligibility conditions with your coordinator.
You register for the Local Exam through your ACS Local Section Coordinator, who organizes and supervises the exam in your region. Your chemistry teacher or the ACS Local Section directory can help you find the right coordinator for your school.
Results decide every step. Local Section coordinators nominate their top scorers for the National Exam, the National Exam selects the top 20 for the June Study Camp, and four of those students are chosen at camp to represent the United States as Team USA.
The National Exam carries three national honors: Top 20, High Honors, and Honors. Higher up the pathway, the four members of Team USA compete for medals at the International Chemistry Olympiad each July.
Students who are neither U.S. citizens nor U.S. permanent residents may take the Local Exam, but cannot be nominated for the National Exam. Students elsewhere should confirm their own national selection route for the IChO.
For the 2027 season, ACS registration opens on 1 November 2026. Contact your Local Section Coordinator for school eligibility, local deadlines and exam arrangements.
Ready to enter the 2027 season?
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