By Dr. Harman Brah, MD · Judge, California Science & Engineering Fair
There is no application for Regeneron ISEF. Students qualify by winning at a Society-affiliated local, regional, state or national fair. For a Bay Area student, that means the road to ISEF runs through your county fair.
ISEF 2027 is in Los Angeles in May 2027, which makes this a good year to understand the path.
Who is eligible
To compete at ISEF, a student must be in grades 9 to 12 (or equivalent), be selected by an affiliated fair, and not yet be 20 on or before May 1 before the fair. A project may include no more than 12 months of continuous research.
The scale is international. The 2026 fair drew 1,725 finalists from nearly 70 countries, regions and territories, selected from 365 affiliated fairs.
The Bay Area path, county by county
Your student enters the fair for their county. CSEF’s own listings say a county fair is the only one authorized to qualify students from that county’s schools for the state fair, so this is not a choice families get to shop.
Santa Clara County: the Synopsys Championship. The Championship is March 4, 2027. Its grand prize winners qualify to compete at ISEF. Projects that need SRC/IRB pre-approval are due November 13, 2026 (early due date November 2), and new participants apply by January 8, 2027.
Alameda County: the Alameda County Science & Engineering Fair. Judging is Saturday, March 13, 2027 at Chabot College, with awards on March 27. The fair is affiliated with both the California Science & Engineering Fair and Regeneron ISEF.
San Mateo County: the San Mateo County STEM Fair. The 40th annual fair is held virtually on Saturday, March 20, 2027. High school students compete directly at this fair as their route to the state fair.
Contra Costa County. The county fair is held each March at Los Medanos College in Pittsburg. The 2027 date is not yet posted.
The state level: the California Science & Engineering Fair. CSEF is for students in grades 6 to 12 throughout California, held each April. It is reached through the county fair.
What actually gets a project to ISEF
Every fair on this path is judged the same way at heart. From the judge’s side of the table, these are the things that separate the projects that move on:
- One clear question. Ambitious projects with no result lose to modest projects with a real answer.
- Controls and honest statistics. This is where most projects lose points.
- A student who can defend every choice. The interview at the board decides close calls. A student who can explain why they chose that method, without a script, stands out immediately.
- Work that is visibly the student’s. A project that looks parent- or mentor-built is seen through quickly.
Start with the calendar, not the topic
The single most common mistake is picking an exciting topic in December that needs pre-approval the student can no longer get. Work backward from your county fair date: if the question involves people, animals or microorganisms, the review paperwork belongs in the fall.
Where we fit
Our mentors include Dr. Harman Brah, a physician who judges at the California Science & Engineering Fair, and Wesley Hatcher, PhD, an organic chemist at UC San Diego and NSF Graduate Research Fellow. Our students have been ISEF and Regeneron STS semifinalists and category award winners, and Prajval and Bhuvan took 1st place at the Alameda County fair and 3rd at the state fair. See our research mentorship tracks and fair calendar.
FAQ
Can you apply to ISEF directly?
No. Students qualify by winning at a Society-affiliated local, regional, state or national fair.
Which fair should a Bay Area student enter to reach ISEF?
The fair for their county: the Synopsys Championship for Santa Clara County, the Alameda County Science & Engineering Fair, the San Mateo County STEM Fair, or the Contra Costa County fair.
Where is ISEF 2027?
Regeneron ISEF 2027 is in Los Angeles, California, in May 2027.
What grades can compete at ISEF?
Grades 9 to 12, or equivalent. Students must not be 20 on or before May 1 before the fair.
More guides on this topic
- Can University Lab Research Go to the County Science Fair and ISEF?
- Does Your Student Need a Research Mentor for STS or ISEF?
- Regeneron STS vs ISEF: Which Should Your Student Do?
- Middle School Science Fair in the Bay Area: How Grades 6 to 8 Reach the State Fair
- Regeneron STS 2027: What to Finish Before the November 5 Deadline
Planning a Science Fair or STS Project?
This guide is the general version. Work one on one with a physician who judges at the California state fair and a PhD chemist, on a project your student owns from the first question to the final poster.