Top math high schoolers resigned to the idea that math can’t be “enormous fun” should really give MathILy a shot.
MathILy (Serious Mathematics Infused with Levity) is a five-week intensive, residential summer program for mathematically talented students with an insatiable curiosity for advanced mathematics. Hosted on the campus of Bryn Mawr College in Pennsylvania, the program enrolls approximately 45 students each summer and offers interactive, inquiry-based instruction in undergraduate- and graduate-level mathematics you rarely find in high school.
At MathILy, students spend five weeks from June 14 to Aug 8 (2026 dates) studying advanced mathematical ideas in a small, highly interactive community. The program is held at Bryn Mawr College and is led by Sarah-Marie Belcastro, MathILy’s director and lead instructor. It is designed for students who already enjoy challenging math problems, especially proof-based reasoning, but want exposure to material beyond the standard high school curriculum.
The “levity” part of MathILy is central to how the program presents itself. As the program explains, “Many summer mathematics experiences are organized on the principle that simply combining smart people with mathematics will result in learning and fun. This is a true principle—but why not do better? MathILy promises a focused and individually tailored effort that elicits massive learning, enormous fun, and significant personal growth.” In practice, this means the structure is closer to an intensive seminar than a traditional class or research internship.
Unlike programs such as RSI, MathILy is not primarily a research internship and does not position itself as the single top research program for mathematically excellent secondary students. Its prestige is more specific: it is a top-echelon enrichment program for students who want deep exposure to advanced mathematical thinking. The curriculum focuses heavily on discrete mathematics, including topics such as combinatorics, graph theory, affine geometry, theoretical linear algebra, proof techniques, number theory, probability, group theory, and cardinality. MathILy is also part of Mathematical Staircase, Inc., a non-profit organization that runs MathILy, MathILy-Er, and MathILy-EST.
Overall, MathILy is best described as a highly selective and well-regarded summer math program, particularly for students who want to show depth in proof-based mathematical thinking. Its admissions value comes from what it demonstrates about a student: overall thinking skills and mathematical skills, problem solving skills, maturity, and the ability to thrive in a demanding intellectual community.
MathILy has existed across “many previous summers,” and is generally regarded as one of the stronger summer mathematics experiences for high schoolers, especially for students whose interests lean toward proof-based mathematics rather than competition math alone. The strongest public admissions-facing signal is that MIT Admissions includes MathILy on its list of summer math programs that MIT applicants “seem to especially like,” alongside programs such as Mathcamp, PROMYS, the Ross Program, SUMaC, HCSSiM, and HSMC.
MathILy students often go on to strong undergraduate and graduate pathways in mathematics, computer science, and adjacent fields. Public program profiles and online alumni references include students who later attended institutions such as Harvard, Stanford, MIT, Cornell, Brown, and the University of Iowa, with some continuing into graduate study in math at universities such as UC Berkeley, Harvard, Rutgers, and Indiana University.
While MathILy does publish an acceptance rate every year, its 2024 program report provides unusually clear admissions data. That year, MathILy received 2,052 Short Forms, 833 Not-as-Short Forms, 746 EARs, and 675 completed applications. It admitted 60 students, for an acceptance rate of about 9%, with a yield rate of roughly 73%. Since MathILy currently enrolls approximately 45 students, the practical cohort size remains very small, even if the number of offers varies by year.
That makes MathILy highly selective, comparable to or lower than many Ivy League undergraduate acceptance rates. Its selectivity comes from a combination of small cohort size, a demanding application process, and the Exam Assessing Readiness (EAR), a four-hour math assessment designed to evaluate readiness for advanced, proof-based mathematics.
Students apply to MathILy and MathILy-Er through the same application, and the program decides placement based on suitability. Key eligibility details include:
MathILy is designed for mathematically talented high school students, but its ideal applicant is not limited to students with perfect contest records. The program specifically says it seeks:
Strong applicants are likely to enjoy difficult, proof-based problem-solving and be ready for an interactive learning environment where students discover mathematics, share conjectures, and explain proofs. MathILy is especially well suited for students who want to build stronger thinking habits, problem-solving habits, and mathematical writing habits in preparation for advanced college-level work.
MathILy uses a staged application process for both MathILy and MathILy-Er. Students do not apply separately to the two programs; admitted students are placed into the appropriate program based on academic suitability. The application is centered less on transcripts and standardized test scores, and more on mathematical readiness, especially the EAR, or Exam Assessing Readiness.
MathILy uses rolling admissions starting in the spring, after the EAR is released to applicants. This matters because students who complete their applications earlier may receive decisions earlier, and international students who may need a visa are specifically encouraged to apply well before the full-consideration deadline. Once an application is complete, including recommender comments, MathILy says applicants should receive a decision in “a week or so.”
Note that the below dates are for 2026 and have already passed. Readers should use them as a guide for next year’s applications.
MathILy students spend five weeks of what MathILY calls “maximized mathematical marvelousness”: an intensive, interactive environment built around classes, problem-solving, proof-writing, discussion, and collaboration. The program follows a 2-1-2 structure: students begin with two weeks of Root Class, which gives everyone a shared mathematical foundation; continue into a Week of Chaos, when students and instructors explore many shorter topics suggested by the community; and finish with two weeks of Branch Classes, which go deeper into more advanced mathematical areas.
Across the program, students learn how to create mathematics, not simply absorb it: they ask questions, test patterns, and work through new ideas with classmates, while instructors provide guidance, structure, and feedback. The result is a period of mathematical development and individually tailored effort that elicits massive learning for students. For 2026, likely Branch Class topics include polytopes, chip-firing games on graphs, and the mathematics of paperfolding.
A typical MathILy day includes breakfast, class, lunch, a mostly free afternoon, Daily Gather, dinner, and evening class. Classes meet for about seven hours per day, split into two shifts: morning and evening sessions, six days per week.
Afternoons are partly open, but students may also use that time to write summaries of what happened in class, spend time with classmates, play games, music, or frisbee, and participate in informal community activities. The program also includes a “life seminar” with discussions about college choices, careers in and outside the mathematical sciences, mathematical insecurity, preferred gender pronouns, and other topics connected to living and learning in a serious math community. There is usually at least one program trip to Philadelphia.
MathILy is not free, but it does offer need-based financial aid. For 2026, the program fee is $6,175, or $1,235 per week for the five-week residential program. MathILy states that financial aid is based entirely on need, and that the entire fee may be waived for an admitted student with significant need. For 2026, the program also says it will meet the demonstrated financial need of every admitted student, with priority given to U.S. students over international students.
The program fee covers the residential experience at Bryn Mawr College, including dorm housing, food, instruction, and program activities. MathILy notes that the dorms have air conditioning, students are very likely to have single rooms, food is provided through Bryn Mawr and laundry is free. Travel to and from campus is not described as included in the program fee; MathILy says admitted students will receive practical details on getting to campus by plane, train, or car. After admission, students must pay half of the fee to reserve their spot, with the full fee, minus any financial aid, due by May 19, 2026.
MathILy gives students a credible way to demonstrate advanced mathematical interest, especially if they are applying to selective colleges as prospective math, computer science, engineering, physics, economics, or quantitative social science students. Its value comes from the combination of selectivity, intensity, and intellectual fit:
MathILy’s admissions value is that it shows that a student sought out and succeeded in a rigorous mathematical environment. For a student applying to highly selective colleges, MathILy is strongest when it fits into a broader profile that demonstrates significant personal growth.
The most program-specific advice is this: prepare for MathILy by learning how to think and write like a mathematician. Students should practice proof-writing, discrete math, and open-ended problem-solving; ask a recommender who has seen them handle difficult mathematics; and use the application essays to show real excitement for living in a community where students spend weeks exploring advanced math together.
MathILy is worth it for students who genuinely want a rigorous, proof-based mathematics experience rather than a resume-only summer program. Academically, its main value is the chance to spend five weeks studying undergraduate- and graduate-level math in a small, highly interactive community, with classes taught by Ph.D. mathematicians and supported by graduate students. It carries college admissions value because MathILy is selective, academically serious, and recognized by MIT Admissions as one of the summer math programs its applicants often value, though it should not be seen as a guaranteed admissions boost.
The main tradeoff is opportunity cost: students who want lab research, a formal research paper, or college credit may be better served by a different program. But for students who love mathematics for its own sake and want to test themselves in a demanding residential math community, MathILy is a strong option, especially because it offers generous need-based financial aid.
MathILy is in the same serious category as PROMYS, Ross, and Canada/USA Mathcamp, but it is usually seen as slightly less historically established and somewhat less famous than those three. PROMYS and Ross have longer histories and especially strong reputations for number theory and proof-based mathematical training, while Mathcamp is often viewed as one of the most selective and intellectually broad summer math communities. MathILy is newer by comparison, but still highly respected: MIT Admissions lists it alongside Mathcamp, PROMYS, Ross, SUMaC, HCSSiM, and HSMC, and its 2024 admissions data showed about a 9% admit rate, which places it in the highly selective tier.
MathILy and MathILy-Er are related residential summer math programs, but they are designed for students at different levels of mathematical readiness. MathILy is the more advanced program, while MathILy-Er is intended to prepare particularly promising students for MathILy or other highly selective residential summer math programs. Students submit one application, not separate applications for each program, and the program decides placement based on academic suitability.
Yes. You can get into MathILy without a competitive Math Olympiad background. Math competitions can help show mathematical interest, but MathILy’s application is not built around AMC, AIME, USAMO, or Olympiad credentials. The most important piece is the EAR, or Exam Assessing Readiness, which MathILy describes as a four-hour assessment meant to show what a student can do in a MathILy or MathILy-Er class.
“Root, Chaos, and Branch” describes the three-part structure of MathILy’s five-week curriculum:
Every single class session at MathILy is designed and directed by a Lead Instructor, a title reserved exclusively for professionals who hold a Ph.D. in mathematics and have documented expertise in university-level, inquiry-based learning. MathILy ensures that a terminal-degree mathematician is actively steering the classroom environment at all times. Each Lead Instructor works alongside one or two Apprentice Instructors, typically graduate students or advanced undergraduate mathematics students.
MathILy is a highly selective and well-regarded summer math program for students who want to go beyond standard high school coursework and immerse themselves in advanced, proof-based mathematics. It is especially strong for students interested in math, computer science, theoretical STEM fields, or any area that rewards rigorous problem-solving and abstract reasoning.
Students who are curious about MathILy should begin exploring advanced math opportunities early, whether through math clubs, proof-based problem sets, competitions, independent reading, or other selective summer programs, so they can build both the skills and confidence needed for a demanding environment like MathILy.
Those looking to learn more about research programs for high school students can check out our article categorizing them here. There are many summer mathematics experiences similar to MathILy, including the following:
For high school students searching for prestigious summer research programs respected and valued by colleges, Pioneer Academics is a great alternative to this featured program.
Based on a recent survey from Pioneer Academics alumni, 71 percent of Pioneer Research scholars’ college admissions records were to the top 20 US colleges and universities. Six percent of Pioneer’s alumni attended university-affiliated summer programs.
If you’re interested in conducting the highest level of research for high school students, consider joining a Pioneer information session to learn more about the Pioneer Research Institute.
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