The short answer: ISEF, the Regeneron International Science and Engineering Fair, is the largest pre-college science competition in the world. Students in grades 9 to 12 cannot sign up for it directly. They qualify by winning at a science fair affiliated with Society for Science, the nonprofit that runs ISEF. In 2026, more than 1,700 finalists from 64 countries, regions and territories competed in Phoenix for more than $7 million in awards, with a top prize of $100,000. ISEF 2027 is in Los Angeles in May.
For a parent, the practical questions are: how does my child get there, how long does it take, what does it cost us, and does it matter for college? This guide answers each.
What ISEF is, in plain terms
Think of ISEF as the final round of a tournament that starts at local fairs. Each affiliated fair, whether a school district fair, a regional fair or a state fair, gets to send a set number of projects to ISEF. The 2026 finalists came from 365 affiliated fairs.
At ISEF itself, students set up a display of their research and are interviewed by judges who are working scientists and engineers. Projects compete in categories such as biochemistry, computational biology, physics, and behavioral and social sciences, and then for special awards from companies, universities and agencies.
Two eligibility rules matter most for planning: a student must be in grades 9 to 12 (or the equivalent) and must not have turned 20 by May 1 before the fair. Each student enters one project.
How students qualify, step by step
1. Find the right affiliated fair. Society for Science keeps a directory of affiliated fairs. Each fair has its own rules, fees and deadlines, and some only accept students from certain counties or schools. If your child's school does not run a science fair, many regional fairs accept independent entries.
2. Complete the paperwork before the research starts. ISEF has detailed rules for projects involving human participants, animals, or hazardous materials, and some require approval before any data is collected. Projects done outside a school lab need an adult sponsor. ISEF Forms and Teacher Sponsors explains what is required.
3. Do the research. This is the long part, typically several months. Judges reward original questions, sound methods and a student who understands every decision in the project.
4. Compete at the affiliated fair. Most regional and state fairs run between January and April. Top projects are nominated to ISEF.
5. Compete at ISEF in May. Finalists spend a week at the fair, with judging, public exhibition and award ceremonies.
The step most families underestimate is step 3, and specifically how much better a project gets with a mentor who has done research before. How to Get Into ISEF has the detailed qualification walkthrough.
Where structured mentorship fits
ISEF judges score the science, and the science starts with the question. Students working alone often pick questions that are already answered, or too big to finish. That is the gap a research mentor closes.
The YRI Fellowship pairs students with a PhD mentor for ten weeks of one-on-one work: finding the question, designing the study, collecting data and writing the paper, with ISEF and JSHS preparation built in. Two Fellows qualified for ISEF 2026. The Published Work page lists Fellows' papers and competition results, and the tuition page shows what is included.
Timeline: when your child should start
Most regional fairs happen in late winter or spring, so the research has to be finished by then. Working backward:
| When | What should be happening |
|---|---|
| Summer before | Choose a question with a mentor, read the literature, plan the method |
| September to October | Submit any required approval forms, start collecting data |
| November to December | Finish data collection and analysis |
| January to February | Write up, build the display, practice the interview |
| February to April | Affiliated school, regional and state fairs |
| May | ISEF |
The common mistake is starting in the fall of the competition year with no question yet. It can work, but it leaves no time to recover from a failed experiment. Science Fair Deadlines 2026-27 has the calendar.
By grade:
- 9th grade: Ideal for a first project and a first fair. Students learn how judging works with low stakes.
- 10th grade: A second, more ambitious project has a better chance of advancing.
- 11th grade: A strong year to compete, and the last one whose results appear fully on college applications.
- 12th grade: Students can still compete, but results from a spring fair arrive after most college decisions are made.
What it costs families
ISEF does not charge finalists to compete, but the road there has costs:
- Fair registration: Set by each affiliated fair. Many are free or low cost.
- Materials: Computational projects can cost almost nothing beyond a laptop. Wet-lab projects cost more.
- Display and printing: A poster or display board.
- Travel: To regional and state fairs, and to ISEF if your child qualifies. Ask your affiliated fair whether it covers finalist travel.
- Mentorship: Free if your child finds a professor or teacher, paid if you use a program. How Much Do Research Programs Cost compares options.
What ISEF means for college admissions
Being named a finalist tells an admissions reader that a project won at a judged fair and was selected to represent it internationally. It is easy to verify and widely recognized.
Winning an award at ISEF is rarer and stronger again.
Competing regionally without advancing still matters, more than many parents expect. It shows the student finished an original project and defended it in front of judges. Combined with a paper in a legitimate venue, it is a strong research record.
What ISEF does not do is replace the transcript. Colleges weigh grades in college-prep courses above every other factor, so research works best on top of strong academics. How Research Papers Help With Ivy League Admissions explains how readers use research.
Real YRI students on the ISEF path
Mubashir S. built a low-resource neural network pipeline for classifying gravitational-wave signals, designed to run without expensive GPU hardware. Working with his YRI mentor, he turned the idea into a paper, and the project qualified him to represent Pakistan at Regeneron ISEF 2026. Read his case study.
Avyay G. started with YRI in 9th grade, won 1st place at his science fair and qualified for state. Read his case study.
The pattern: start early, get a mentor who has done research, and finish the project well before the fair.
How ISEF compares with other competitions
| Competition | Format | Who can enter | How to get in |
|---|---|---|---|
| Regeneron ISEF | In-person fair, judge interviews | Grades 9 to 12 | Win at an affiliated fair |
| Regeneron STS | Written research application | High school seniors | Apply directly; 2027 deadline November 5, 2026 |
| JSHS | Oral research presentation | High school students | Regional symposium, then national |
Regeneron STS names 300 scholars and 40 finalists, with a top award of $250,000. JSHS is backed by the U.S. military's STEM programs and administered by the National Science Teaching Association. One strong project can often be entered in more than one. Regeneron STS Guide and How to Win JSHS cover each.
How parents can help
Next steps
If your child wants to compete at ISEF in 2027 or 2028, the question and the mentor come first. See what Fellows have produced on the Published Work page, read how the Fellowship runs, and apply when ready. It is free, takes about ten minutes, and decisions come within 48 hours.
Free download: The 2026-27 Science Fair Blueprint
All 25 competitions, deadlines, eligibility traps, and what the judges in each one actually score. Free to share with your school.
Frequently Asked Questions
What is ISEF?
The Regeneron International Science and Engineering Fair is the largest pre-college science competition in the world, run by Society for Science. In 2026 it brought more than 1,700 finalists from 64 countries, regions and territories to Phoenix, with more than $7 million in awards.
How does a student qualify for ISEF?
Students cannot apply directly. They must be selected by a Society for Science affiliated fair, usually a regional or state fair, after winning there. Students must be in grades 9 to 12 and under 20 on May 1 before the fair.
When should my child start preparing for ISEF?
Ideally the summer before the competition year, so the research is finished before regional fairs in late winter. Starting in 9th or 10th grade leaves time for a second, stronger project.
Does my child need a lab to do an ISEF project?
No. Many competitive projects are computational, using public datasets and code that runs on a laptop. Projects involving human participants, animals or hazardous materials need prior approval under ISEF rules.
Can my child do an ISEF project without a mentor?
It is possible but hard. Mentors help students pick an original, feasible question and avoid method errors that judges catch. Mentors can be teachers, university researchers, or a structured program like the YRI Fellowship.
Is ISEF worth it for college admissions?
Being a finalist is a recognized, verifiable distinction. Competing at a regional fair also shows the student finished and defended original research. It strengthens an application but does not replace strong grades.
What is the difference between ISEF and Regeneron STS?
ISEF is an in-person fair for grades 9 to 12 that requires qualifying through an affiliated fair. Regeneron STS is a written application open to seniors, with a deadline of November 5, 2026 for the 2027 competition.
Where is ISEF 2027?
Los Angeles, California, in May 2027, according to Society for Science.
Sources
- Society for Science: Regeneron ISEF
- Society for Science: Regeneron ISEF 2026 Grand Awards press release
- Society for Science: ISEF FAQ
- Society for Science: Affiliated Fair Network
- Society for Science: Regeneron Science Talent Search
- JSHS: Junior Science and Humanities Symposium
- NACAC: Factors in College Admission