Regeneron ISEF 2026 vs MLH Fellowship

Comparing two elite STEM opportunities. Regeneron ISEF 2026 is a competition while MLH Fellowship is a internship.

Regeneron ISEF 2026 MLH Fellowship
Prestige Tier Tier 1 — Elite Tier 2 — Highly Competitive
Type Competition Internship
Organization Regeneron Major League Hacking (MLH)
Acceptance Rate Roughly 1,700 finalists are selected from 365 affiliated fairs worldwide. Getting to ISEF requires first winning regionally, which itself is competitive. Estimated <1% of all science fair participants globally reach ISEF. At the ISEF itself, approximately 600 of the 1,700 finalists (~35%) receive some award. Not publicly disclosed; competitive program but exact rate unknown
Applicants Millions of students compete in science fairs globally each year; approximately 1,700–1,800 reach ISEF as finalists Not publicly disclosed; appears to have multiple cohorts annually
Deadline Rolling
Cost to Apply Free Free
US Only No / International No / International
Grades Grades 9–12 (high school students only; middle schoolers compete in the separate Junior Innovators Challenge) College students and above (program appears designed primarily for undergraduates; high school eligibility unclear)
College Impact ISEF finalist status is one of the most powerful extracurricular credentials in college admissions. Being named an ISEF finalist (simply qualifying) is Tier 1 on most admissions frameworks. Grand Awar... Highly valued in college admissions and recruiting. Shows: (1) Real-world experience with production-grade code, (2) Demonstrated commitment to open-source/collaborative development, (3) Recognition b...