MIT PRIMES is a free, year-long math and bioinformatics research program for high school sophomores and juniors living in the United States, run by the MIT Department of Mathematics, and admission is decided mainly by an entrance problem set and an interview. Local students in Greater Boston attend MIT PRIMES in person; everyone else in the US applies to PRIMES-USA, which runs the same way by video call. The application deadline for the 2027 program year was November 2, 2026, with decisions in early January 2027. MIT does not publish an acceptance rate.
This guide is written by YRI Fellowship, a paid research mentorship program, and we say that upfront. Every fact about PRIMES comes from MIT's own pages or named third-party guides as of November 2026, all linked in the Sources section.
What MIT PRIMES is
PRIMES stands for Program for Research in Mathematics, Engineering and Science. It is an after-school research program in which high school students work on unsolved problems under the guidance of MIT graduate students and faculty, and it received a 2020 American Mathematical Society award for an exemplary program in a mathematics department. Since 2025 the program has narrowed its focus to mathematics and bioinformatics; there is no new admission to the computer science section.
MIT's homepage reports that at the 2026 Regeneron Science Talent Search, PRIMES students placed 4th, 5th and 9th and two more were finalists, that two PRIMES students were named 2026 Davidson Fellows, and that five of the six members of the 2025 US International Math Olympiad team came through PRIMES. If MIT itself is the goal, read this alongside how to get into MIT.
The PRIMES tracks
PRIMES is a family of programs. Families often apply to the wrong one, so here is the full map.
| Track | Who it is for | Format | Cost |
|---|---|---|---|
| MIT PRIMES | Sophomores and juniors within driving distance of Boston | Year-long research or guided reading, weekly meetings on the MIT campus | Free |
| PRIMES-USA | Sophomores and juniors anywhere else in the US | Same program by teleconference, mentored by MIT and partner university researchers | Free |
| Menezes Challenge PRIMES Circle | High school students within commuting distance of Boston, especially those who have overcome barriers to learning | Spring-term guided reading in pairs with an undergraduate mentor, expository paper in May | Free, $5 SlideRoom fee, waivers available |
| Yulia's Dream | Students in grades 10 and 11 from Ukraine | Online reading groups and research, Ukrainian, English or Russian | Free |
| MathROOTS | Nationally selected high-potential students | Two-week residential summer program with MIT Admissions | Free |
| CrowdMath | Any high school or college student worldwide | Online collaborative research project with Art of Problem Solving | Free |
| PRIMES STEP | Greater Boston students in grades 7 to 9 | Year-long math enrichment | Affiliate program |
The two research tracks, MIT PRIMES and PRIMES-USA, share one application portal and one problem set. PRIMES-USA started in 2013 with five students and had grown to 47 by 2024, with partner institutions including Cornell, Stanford and the University of Michigan.
Eligibility
- Grade. High school juniors and sophomores, including homeschooled students of the same age. Seniors cannot apply.
- Location. You must physically reside in the United States. International students attending an in-person US school are eligible. US citizens living abroad are not, and neither are students abroad enrolled in a US online school. Everyone else is pointed to CrowdMath.
- Preparation. Proof-based math is recommended but not required. MIT says it prefers applicants who meet at least one of these: USAMO or USAJMO qualifier, an A in a college-level proof-based math course (online counts), participation in a summer math program such as MathCamp, PROMYS, Ross, SUMaC, HCSSiM or AwesomeMath with a counselor's letter, or a recommendation from a college math professor.
Bioinformatics applicants solve the same math problem set and should also describe their biology background. PRIMES research areas in 2026 included machine learning and theoretical computer science within the math section; see our machine learning project ideas for high school for that side.
The entrance problem set
This is the heart of the application. Each year MIT posts a new PRIMES Math Problem Set, and applicants submit written solutions as part of the application. The rules from MIT's application page:
- Submit proofs, not answers. The file should contain full arguments and partial results where you could not finish. Writing in LaTeX is strongly recommended.
- Aim for 70%. MIT encourages students to apply if they solve at least 70% of the problems. The same set is used for math and bioinformatics.
- Any resource, no people. Books, websites and AI models are allowed, but you must cite them. If an AI tool helped you reach a correct solution, you must name the model and the prompts and rewrite the solution in your own style. Help from other people is not allowed.
- Do not post the problems. Posting them on problem-solving sites leads to disqualification, and MIT may notify parents and recommenders.
- Anonymize the file. The filename must begin with your last name and no other identifying information may appear inside.
Shortlisted applicants are then invited to an online interview, in batches, where they may be asked about their solutions, the reading material, and the books and courses they listed.
Timeline and deadlines
PRIMES runs on a calendar year, and the application closes the November before.
| Milestone | Date |
|---|---|
| Application deadline (2027 program year) | November 2, 2026, 11:59 p.m. EST |
| Recommendation letters due | November 6, 2026 |
| Decisions | Early January 2027, all applicants at once |
| Phase I, guided reading | January 1 to Pi Day (March 14); 5-page reading report due |
| Phase II, active research | Mid-March to June 15; interim report due early June |
| Phase III, independent summer work | June 15 to August 31, flexible |
| Phase IV, write-up | September 1 to December 31; conference talk mid-October, penultimate draft December 1, final paper January 15 |
The time commitment in Phases I and II is at least 10 hours a week, including a 1.5-hour weekly meeting with the mentor. Final papers are posted on the PRIMES website.
The 2026 deadline has passed. The next cycle, for the 2028 program year, opens in fall 2027; check the official page for dates. PRIMES Circle runs on its own calendar, with applications due October 30 and the program from February to May. Yulia's Dream closes September 15 with decisions in early November.
Cost
MIT PRIMES, PRIMES-USA, PRIMES Circle and Yulia's Dream are all free. There is no tuition and no stipend, and PRIMES-USA requires no travel, only a computer with administrator rights, a webcam and high-speed internet. The one fee in the family is PRIMES Circle's $5 SlideRoom application fee, which can be waived.
Acceptance rate
MIT does not publish an acceptance rate, and it does not publish the number of applicants. What it does publish is the size of each section. For 2026, the MIT PRIMES research areas page lists 48 students in Junior Math, 20 in Sophomore Math and 8 in Bioinformatics, which is 76 students across the in-person and remote research tracks combined. MIT's own description of PRIMES-USA says "a small number of candidates is admitted" and "a very advanced background is expected."
Pioneer Academics reports a single-digit acceptance rate, often cited around 5 to 10%, and notes it is not official. Treat any precise percentage as an estimate. The summary: roughly 75 places a year, nationwide, for students who can already write proofs.
What the application asks for
Beyond the problem set, the online application includes:
Admitted students cannot pick their project. PRIMES staff match each student to a mentor and assign an individual or group project of at most three students, and accepting the offer means accepting the assignment. MIT says group placement says nothing about the strength of the application.
How to be competitive
The students who get in have usually done three things, and none of them can be started in October.
- Learned to write proofs. A proof-based course, a summer math camp, or working through a text from MIT's reading list. The problem set is graded on arguments, not final numbers.
- Worked old problem sets. MIT posts past entrance problem sets with solutions. Doing several under honest conditions, then comparing your write-ups to the official solutions, is the closest thing to practice for the live one.
- Built a record a mathematician will vouch for. The preferred criteria all point the same way: a USAMO qualification, an A in a college course, a camp counselor who saw you work, or a professor who knows you.
Our guide to how to do AI and ML research in high school covers the computational side for students leaning toward bioinformatics.
The odds, frankly
PRIMES is one of the most selective research programs in the country, and it is designed for a specific student: one who already lives in proof-based mathematics by 10th or 11th grade. If your student is strong in school math but has not yet met a proof, a rejection says nothing about their potential as a researcher. It says they applied to a program built for a different starting point.
There is also a timing problem. Decisions arrive in January and the final paper is due the following January, so a junior who starts PRIMES finishes the paper after early-decision deadlines have passed. For a student whose goal is a completed, verifiable research result in time for college applications, the calendar matters as much as the odds. Our 2027 summer research deadlines list lays out the alternatives by date.
If you do not get in
Look at what PRIMES admits have in common. They did serious work before they applied, and they had a mentor who could say so. The same pattern holds for RSI, Simons and every selective program in our guide to research opportunities for high school students.
The YRI Fellowship is built to produce that record on your own timeline. It is 10 weeks of one-on-one work with a PhD mentor matched to the student's field, ending in a first-author paper submitted to a peer-reviewed IEEE, Springer or Elsevier venue. ISEF and JSHS preparation and a mentor recommendation letter are included, mentorship continues at no extra cost until the paper is published, and 87% of Fellows publish. It costs $2,997, with a three-month payment plan and scholarships case by case. Admissions are rolling, so a sophomore can finish a paper before the November PRIMES deadline and apply with a published result and a PhD recommender, which is close to the profile the preferred criteria describe.
Families use it before a PRIMES application, as the backup after a January no, or for the student whose strengths are in applied machine learning, biology or engineering rather than proofs. Read how to publish a research paper in high school for what that process looks like, and how to choose a research topic to find the right question.
Download the YRI Fellowship brochure
The program, the outcomes, the mentors and the tuition, in one PDF you can read with your family.
Related guides
- How to get into MIT
- Summer research programs for high school students, 2027 deadlines
- Research programs for high school students in Massachusetts
- YRI vs RSI vs SSP, complete comparison
- Computer science research programs for high school students
- Machine learning project ideas for high school
Frequently Asked Questions
What is the MIT PRIMES acceptance rate?
MIT does not publish one. In 2026 the research sections held 76 students (48 Junior Math, 20 Sophomore Math, 8 Bioinformatics). Third-party guides estimate a single-digit rate, often cited at 5 to 10%, but no figure is official.
What is the difference between MIT PRIMES and PRIMES-USA?
They are the same program with the same application and problem set. MIT PRIMES is for students within driving distance of Boston who meet mentors in person; PRIMES-USA is for students everywhere else in the US, mentored by video call.
Who is eligible for MIT PRIMES?
High school sophomores and juniors, including homeschooled students, who physically reside in the United States. Seniors, students abroad and students at US online schools from outside the country are not eligible; CrowdMath is open to them instead.
How hard is the MIT PRIMES problem set?
It is a set of proof-based problems that MIT says you should apply if you can solve at least 70% of. Any resource except other people is allowed, with citations, and shortlisted students defend their solutions in an interview.
When is the PRIMES application deadline?
The deadline for the 2027 program year was November 2, 2026, with recommendations due November 6 and decisions in early January 2027. The next cycle opens in fall 2027; check the official page for exact dates.
Does MIT PRIMES cost anything?
No. MIT PRIMES, PRIMES-USA and Yulia's Dream are free with no tuition and no stipend. PRIMES Circle charges a $5 application fee that can be waived.
Can international students apply to MIT PRIMES?
Only if they attend an in-person school in the United States. Students outside the US can join CrowdMath, MIT's free online collaborative research project, and Ukrainian students in grades 10 and 11 can apply to Yulia's Dream.
What should my student do if they do not get into PRIMES?
Produce the research record on their own schedule. The YRI Fellowship pairs students one-on-one with a PhD mentor for 10 weeks to finish a first-author paper submitted to a peer-reviewed venue, with competition preparation included, and rolling admissions mean a student can start before the next PRIMES deadline rather than wait for it.
Sources
- MIT PRIMES: homepage (tracks, deadline, 2026 results, AMS award)
- MIT PRIMES: program details (MIT PRIMES, PRIMES-USA, PRIMES Circle, PRIMES STEP, US residency rule)
- MIT PRIMES: how to apply (eligibility, preferred criteria, application components, problem set rules, 70% guideline, deadlines, decisions)
- PRIMES-USA: how to apply (same components and deadlines for non-local students)
- PRIMES-USA: program page (four phases, milestones, 10 hours per week, growth to 47 students by 2024, partner universities)
- MIT PRIMES: FAQ (residency rules, no new CS admissions since 2025, project assignment, group size)
- MIT PRIMES: areas of research 2026 (section sizes)
- Menezes Challenge PRIMES Circle (eligibility, format, October 30 deadline, $5 fee)
- Yulia's Dream (grades 10 and 11 from Ukraine, 2026-2027 timetable)
- Pioneer Academics: MIT PRIMES-USA participation guide 2026 (estimated acceptance rate, not official)