Published October 28, 2026.
The STEM summers that still publish a price and a grade rule split into three kinds. RSI and SSP are research. PROMYS and Ross are six weeks of proof-based number theory. MITES and COSMOS are structured coursework, one free and national for rising seniors, one a California state program that starts as early as rising 9th grade. For 2026, RSI was cost-free, SSP charged $11,800 before aid, PROMYS charged up to $8,000, and Ross charged $7,500. If the student is not ready to write proofs, skip PROMYS and Ross. MITES or COSMOS is the better summer. If the student is a junior who wants a lab, RSI is the free application and SSP is the one with a fee and aid after admission.
A comparison, not a ranking
| Program | Kind | 2026 length and place | 2026 cost | Who |
|---|---|---|---|---|
| RSI | Individual research | June 28 to August 8, at MIT. Six weeks. | Cost-free. | Juniors. Seniors may not apply. CEE's spring 2026 newsletter says 100 students. |
| SSP | Team research | Five weeks. Astrophysics, biochemistry, bacterial genomics, or cell biology. 13 campuses, including Guelph in Ontario. | $11,800, including room and board. Aid for all demonstrated need. 2027 fee announced in December 2026. | Juniors only. Ages 15 to under 19 during the program. |
| PROMYS | Number theory | Six weeks at Boston University. The 2026 dates were June 28 to August 8. The site lists June 27 to August 7, 2027. | Up to $8,000 in 2026. Free for U.S. families under $80,000 adjusted gross income, including room and board. | Ages 14 to 18, finished with 9th grade, not a full-time college student. About 80 high school students. |
| Ross | Number theory | June 14 to July 24, 2026, at Otterbein in Ohio and Rose-Hulman in Indiana. | $7,500, with need-based aid. Covers tuition, housing, and meals. | Mostly ages 15 to 18. About 60 first-years per site. In 2023, about 15 percent of complete applications were accepted. |
| MITES Summer | Residential courses | June 20 to July 31, 2026, at MIT. Six weeks. | Free. Students pay transportation. Travel scholarships exist. Food and housing are covered. | 11th grade. U.S. citizen or permanent resident with a current green card. |
| MITES Semester | Online courses, formerly MOSTEC | June 22 to December 6, 2026. Six months, virtual. | Free. Same travel-scholarship note as MITES Summer. | 11th grade, U.S. citizen or green card. Students cannot live or travel outside the U.S. and its territories during the program. |
| COSMOS | Four-week cluster | The 2026 UC San Diego flyer lists July 5 to July 31. UCLA's page lists August 1 as closing day. Campuses: Davis, Irvine, UCLA, Merced, San Diego, Santa Cruz. | $5,518 for California residents, plus a $46 application fee. Need-based aid is available and is separate from admission. | California residents in California high schools. Rising 9th grade through rising 12th grade. |
Simons, Clark Scholars, and Garcia have their own costs and age rules. Read the research guide for those three. AwesomeMath, which is online and priced per course, has its own guide.
How to choose
Match the summer to the work, then to the grade.
- A lab, junior year. RSI if the record is already strong in math and science and the family can meet a December deadline. SSP if the student wants a set experiment with two teammates and can use the aid process after an offer. Read the research guide before adding Simons, Clark, or Garcia.
- Proofs, after 9th grade. PROMYS once 9th grade is finished and the student is 14 to 18. Ross if the student is usually 15 or older and wants the same kind of summer on a different campus. Neither site describes itself as AMC training.
- Courses, with a published price of zero or a state subsidy. MITES Summer or Semester in 11th grade, if the student is a U.S. citizen or green-card holder. COSMOS from rising 9th grade on, only for California residents in California schools.
MIT says it encourages applications from students who are underrepresented in science and engineering, from low-income families, who would be the first in the family to attend college, or who attend a high school that rarely sends students to selective colleges. It also says every applicant who meets the eligibility rules is considered regardless of race or ethnicity. That is a mission statement, not a quota a family can calculate.
An open-enrollment class on a famous campus is a class. If the page does not describe a decision, do not describe it later as a selective admit. A tuition and a brand name are not a comparison.
Questions families ask
What is the difference between this page and the research guide?
This page compares STEM summers that are not all labs: RSI and SSP, the math programs PROMYS and Ross, MITES, and COSMOS. The research guide stays on RSI, Simons, SSP, Clark, and Garcia, and on how to find a lab without a national program. Read that one if the question is research. Read this one if the question is which kind of STEM summer fits.
Is MOSTEC still the name of the MIT program?
MIT now calls it MITES Semester. The site says it was formerly MOSTEC. It is a free, six-month online program for rising seniors, not a one-week campus visit. MITES Summer is the six-week residential program, also free except for transportation.
Can a student outside California attend COSMOS?
No. The 2026 application pages limit COSMOS to California residents attending California high schools. Tuition for those students was $5,518, plus a $46 application fee. The flyer marks non-California tuition as not applicable.
Did Ross publish an acceptance rate?
Its FAQ says that in 2023 about 15 percent of applicants with complete applications were accepted. That figure is for 2023, not for a later year. The same page says the program expects about 60 first-year students at each site.
Sources
Checked October 28, 2026.
- CEE, RSI 2026.
- SSP fees and SSP programs.
- PROMYS for students.
- Ross Mathematics Program and its FAQ, including the 2023 acceptance figure.
- MITES Semester and Summer FAQ.
- COSMOS, who can apply and UC Santa Cruz COSMOS tuition.