MathILy-Er Acceptance Rate 2026
Updated: 27th October, 2026
TL;DR
MathILy-Er is a five-week residential summer math program that does not publish an acceptance rate. It admits about 30 students and calls itself highly selective. A small team reads your full application, including a four-hour exam, so real math talent matters more than a long resume. This guide is for high school students and parents sizing up the odds. If you want to turn math interest into an independent research paper, look at the Lumiere Research Scholar Program. It pairs you 1:1 with a PhD mentor.
Does MathILy-Er publish an acceptance rate?
No. MathILy-Er lists no numeric acceptance rate anywhere on its site. Its facts page calls the program highly selective (as of October 2026). It gives no percentage and no applicant count. Any acceptance rate you see quoted online is an outside guess, not an official figure. So treat round numbers with care. The program talks about who fits, not about odds. Here is what the program does share.
Figure | Detail | Source (year) |
Acceptance rate | Not published. The program calls itself highly selective. | mathily.org facts page (2026) |
Cohort size | About 30 students | mathily.org facts page (2026) |
Tuition | 6,175(1,235 per week) for five weeks | mathily.org facts page (2026) |
Financial aid | Need-based. The full fee may be waived. | mathily.org facts page (2026) |
Eligibility | Mathematically talented high school students, with priority to high schoolers | mathily.org facts page (2026) |
Program dates | June 28 to August 1, 2026. 2027 dates aren't posted yet. | mathily.org facts page (2026) |
Application deadline | Rolling. The 2026 full-consideration date (April 28, 2026) has passed. The 2027 date isn't posted yet. | mathily.org application page (2026) |
Location | Haverford College, Pennsylvania | mathily.org facts page (2026) |
What makes MathILy-Er so competitive?
The main reason is size. MathILy-Er admits about 30 students each summer, per its facts page (as of October 2026). That small cohort keeps the bar high. The program also says its curriculum often includes current research-level mathematics, and that its core is discrete mathematics. It is built for students who are slightly earlier in their math development than MathILy students, so it is not a lower bar. You can read more in our guide to MathILy-Er and our guide to MathILy. Readers look for strong math ability, not a long list of awards.
What are the eligibility requirements?
MathILy-Er is for mathematically talented high school students, per its facts page (as of October 2026). High schoolers get priority. Students who are not in high school may still apply. The application page notes a typical age range of 14 to 17, and applicants outside that range may be asked for more information (as of October 2026). You do not need a specific course list or a contest record to apply. Curiosity and raw math talent carry the most weight.
How does the MathILy-Er application work?
You apply to the pair of programs, not to one by name. Placement is based on math readiness alone, per the application page (as of October 2026). The application has three parts: a Short Form, an Exam Assessing Readiness, and a Not-as-short Form with a recommender. The exam takes about four hours, and you complete it in one time block and return it to the program. Readers judge how you think through problems, not the final answer alone. That is why there is no simple score cutoff.
When can you apply for the 2027 cycle?
MathILy-Er uses rolling admissions that start in the spring, when the exam is released, per its application page (as of October 2026). The 2026 cycle is closed. Its full-consideration deadline was April 28, 2026, and the page says it is no longer considering new applications for summer 2026. The 2027 full-consideration deadline is not yet posted as of October 2026. Apply early, because applications with all parts in get a decision in a week or so. International students who need a visa should apply well before the full-consideration deadline, since the visa process takes a while.
How much does MathILy-Er cost, and is aid available?
Tuition is $6,175, or $1,235 per week, per the facts page (as of October 2026). That covers the five-week residential program. Financial aid is need-based, and the full fee may be waived for an admitted student with significant need. The program says it will meet the demonstrated financial need of every admitted student in 2026. U.S. students get priority for aid, and financial aid forms go to admitted students only.
How can you stand out to the admissions readers?
Show how you think, not only what you know. The exam rewards clear reasoning and honest work on hard problems. Write up your solutions neatly and explain each step, even when you are unsure. Build math depth before you apply. One way is a focused summer program from our list of summer math programs. Then ask a teacher who knows your math mind to write your recommendation.
Is MathILy-Er worth applying to?
Yes, if you love proof-style math and can spend five weeks on campus. The tradeoffs come down to cost, time, and unclear odds.
Pros -
Financial aid is need-based, and the full fee may be waived for an admitted student with significant need.
The curriculum often includes current research-level mathematics, with a discrete math core.
You hear back in a week or so after your application is complete.
There is no test-score cutoff, so the readers weigh your whole application.
Cons -
Tuition is $6,175 before any aid, and aid forms go to admitted students only.
The program is five residential weeks at Haverford College, so you must be away from home.
The four-hour exam and a recommender add work to the application.
No acceptance rate is published, so you can't judge your odds from numbers.
Frequently asked questions: MathILy-Er acceptance rate for high school students
Is MathILy prestigious?
Yes, MathILy is a selective program with a strong name among summer math options. It describes itself as an intensive residential program for mathematically excellent secondary students. Students there make and prove their own conjectures. MathILy-Er is its sibling program, built for students slightly earlier in their math development, and it calls itself highly selective too.
How long does it take for MathILy results to come out?
Fast, once your application is complete. The application page says you get a decision in a week or so after all parts arrive, including your recommender's comments (as of October 2026). Admissions are rolling, so your timing depends on when you finish. Submitting early means hearing back earlier.
Do you apply to MathILy or MathILy-Er?
You apply to both at once. The application page explains that students apply to the set of programs, and staff place you based on math readiness (as of October 2026). More advanced students go to MathILy. Students who are slightly earlier in their math development go to MathILy-Er.
How long is MathILy-Er, and where is it held?
MathILy-Er runs for five weeks at Haverford College in Pennsylvania. The 2026 session ran from June 28 to August 1, per the facts page (as of October 2026). The program is residential. Dates for 2027 are not posted yet, so check the facts page before you plan.
Can international students apply to MathILy-Er?
Yes, international students can apply, but U.S. students get priority for financial aid. If you need a visa, apply well before the full-consideration deadline, because the visa process takes a while. You must get the visa yourself, since the program says it cannot do it for you (as of October 2026).
Not sure you want to spend five weeks on campus, or want a research option that doesn't depend on a cohort of 30? Look at the Lumiere Research Scholar Program. It pairs you 1:1 with a researcher from a top university to produce an independent research project. Apply here. If cost is the main barrier, also look at the Lumiere Research Inclusion Foundation, a non-profit research program for talented, low-income students.
Stephen Turban is the co-founder of Lumiere Education and a graduate of Harvard College, where he earned an A.B. in Statistics before beginning a PhD at Harvard Business School. A former McKinsey & Company consultant and former researcher, his research has been covered by the Harvard Business Review, The Economist, BBC News, Freakonomics Radio, and the Washington Post. In his articles for Forbes, he writes on what students and professionals can learn from high school research, high school passion projects, critical thinking, and mentorship. At Lumiere, he leads a selective research program where students work one-on-one with a research mentor to develop an independent research paper. Connect with him on LinkedIn.