Students eligible for Regeneron ISEF are high school–level researchers (grades 9–12 or equivalent) who are under 20 years old as of May 1 of the competition year and who qualify through an official ISEF-affiliated science fair. The Regeneron International Science and Engineering Fair is the world’s largest pre-college STEM research competition, bringing together top student projects selected from regional, state, and national science fairs worldwide.

Before diving into the specific eligibility rules, it helps to understand how Regeneron ISEF functions within the broader ecosystem of STEM fairs and competitions. Regeneron ISEF is not an open-entry competition and requires students to meet specific academic, age, and fair-affiliation criteria.

What Age and Grade Levels Are Eligible for Regeneron ISEF?

Regeneron ISEF is a pre-college competition, which means eligibility is limited to students who are currently enrolled in high school or an equivalent level of education. Eligible students are typically in grades 9 through 12, or the international equivalent of these grades.

In addition to grade level, there is a firm age requirement. Students must not have reached the age of 20 on or before May 1 of the competition year. This cutoff applies universally, regardless of country or education system. If a student turns 20 after May 1, they remain eligible for that competition year; however, anyone who is already 20 by that date is not permitted to compete.

Homeschooled students and students enrolled in alternative education programs are eligible as long as their academic standing aligns with high school-level education. What matters is not the type of school, but the student’s grade equivalency and age at the time of competition.

What type of research is required for Regeneron ISEF eligibility?

Another essential eligibility condition is that the research itself must be conducted while the student is still in high school. Projects completed after graduation or during full-time college enrollment are not eligible. Regeneron ISEF is designed to showcase original STEM research performed by pre-college students, and this distinction is strictly enforced.

Students may only enter one research project per competition year, either individually or as part of a team. Submitting multiple projects in the same year, even through different fairs, is not allowed.

How to qualify for Regeneron ISEF: Qualification Through an Affiliated Science Fair

One of the most important — and often misunderstood — eligibility requirements is the role of ISEF-affiliated science fairs. Students cannot apply directly to Regeneron ISEF. Instead, they must earn their place by competing in a local, regional, state, or national science fair that is officially affiliated with the Society for Science.

Each affiliated fair is allocated a limited number of ISEF finalist slots. Only the top projects selected by judges at these fairs advance to the international level. This structure ensures that every ISEF finalist has already demonstrated excellence in scientific research, engineering design, and presentation skills.

Students are allowed to participate in only one affiliated fair per year, unless they are advancing to a higher-level fair with the same project. For example, moving from a regional fair to a state fair with the same research is permitted and often expected. However, entering two separate qualifying fairs with different projects in the same year is not allowed.

Because each ISEF-affiliated science fair is allocated only a limited number of finalist slots, qualifying for Regeneron ISEF is highly competitive and requires students to rank among the top projects at their regional, state, or national fair.

Because eligibility depends so heavily on fair progression, understanding deadlines, submission requirements, and review processes is crucial. Many students consult detailed ISEF forms and checklists early in the project timeline to ensure their work remains eligible as it advances through affiliated competitions.

International Student Eligibility

Regeneron ISEF is a truly global STEM competition, welcoming students from more than 70 countries and regions. International students follow the same eligibility standards as U.S. participants: they must be of high school age, under 20 by the cutoff date, and qualify through an approved affiliated fair in their country or region.

All projects presented at ISEF must be displayed and defended in English. While this does not affect eligibility itself, it is an important consideration for international participants preparing abstracts, display boards, and interviews with judges.

Team Projects and Membership Rules

Students may compete either as individuals or as part of a team of two or three members. Team projects are common in engineering and applied science categories, but they come with additional eligibility considerations.

Every team member must independently meet all eligibility criteria, including age, grade level, and enrollment status. If one team member becomes ineligible — for example, by aging out or graduating — the entire team may lose eligibility. Team composition must remain consistent from the qualifying fair through ISEF, with very limited exceptions.

Like individual participants, team members may not participate in more than one project per year.

Compliance, Documentation, and Exceptions

While eligibility is often discussed in terms of age and grade, compliance with research rules plays a significant role in whether a project remains eligible. Projects involving human participants, animals, hazardous chemicals, or advanced laboratory equipment require prior approval and documentation.

Failure to complete required forms correctly or on time can disqualify an otherwise strong project. This is why many students and educators review ISEF-specific paperwork requirements alongside eligibility rules, often using structured forms and checklists as part of their planning process.

There are very few true exceptions to ISEF eligibility rules. The age limit is non-negotiable, and direct entry without an affiliated fair is not permitted. In rare cases where no affiliated fair exists locally, students may be guided toward the nearest eligible fair, but the requirement to qualify through an official channel always remains.

Fast Forward

Students eligible for Regeneron ISEF are high school-level researchers under the age of 20 who have conducted original STEM research and earned selection through an affiliated science fair. Whether competing individually or as part of a team, eligibility depends on meeting academic, age-based, and procedural requirements at every stage of the science fair pathway.

For students serious about competing at the highest level of pre-college STEM research, understanding eligibility early — alongside how ISEF works and what documentation is required — is essential to building a successful and compliant project journey.

Frequently Asked Questions About Regeneron ISEF Eligibility

How do students qualify for Regeneron ISEF?

Students qualify for Regeneron ISEF by competing in an official Society for Science–affiliated science fair and earning selection to advance. Regeneron ISEF does not accept direct entries, and only projects nominated by affiliated fairs are eligible to participate.

Can students apply directly to Regeneron ISEF?

No, students cannot apply directly to Regeneron ISEF. Participation is limited to students who meet eligibility requirements and qualify through an ISEF-affiliated local, regional, state, or national science fair.

Who can apply to Regeneron ISEF?

High school students in grades 9–12 (or the international equivalent) who are under 20 years old as of May 1 of the competition year and who qualify through an affiliated science fair are eligible for Regeneron ISEF.

What grades are eligible for Regeneron ISEF?

Regeneron ISEF is open to students enrolled in grades 9 through 12 or an equivalent level of education, provided they meet age requirements and qualify through an affiliated science fair.

What type of research is required for Regeneron ISEF eligibility?

Eligible projects must involve original scientific or engineering research conducted by the student during high school and must comply with ISEF research, safety, and ethics guidelines.

Is Regeneron ISEF an open-entry competition?

No, Regeneron ISEF is a closed, qualification-based competition. Students must advance through an official ISEF-affiliated science fair to be eligible to compete.