Mathcounts, stylized as MATHCOUNTS, is a non-profit organization that provides grades 6-8 extracurricular mathematics programs in all U.S. states, plus the District of Columbia, Puerto Rico, Guam and U.S. Virgin Islands. Its mission is to provide engaging math programs for middle school students of all ability levels to build confidence and improve attitudes about math and problem solving.
 Mathcounts also provides numerous math resources for schools and the general public.
 Topics covered include geometry, counting, probability, number theory, and algebra.
 Mathcounts was started in 1983 by the National Society of Professional Engineers, the National Council of Teachers of Mathematics, and CNA Insurance to increase middle school interest in mathematics. The first national-level competition was held in 1984. The Mathcounts Competition Series spread quickly in middle schools, and today it is the best-known middle school mathematics competition. In 2007 Mathcounts launched the National Math Club as a non-competitive alternative to the Competition Series. In 2011 Mathcounts launched the Math Video Challenge Program, which was discontinued in 2023.
 2020 was the only year since 1984 in which a national competition was not held, due to the COVID-19 pandemic. The "MATHCOUNTS Week" event featuring problems from the 2020 State Competition was held on the Art of Problem Solving website as a replacement. The 2021 National Competition was held online.
 Current sponsors include RTX Corporation, U.S. Department of Defense STEM, BAE Systems, Northrop Grumman, National Society of Professional Engineers, 3M, Texas Instruments, Art of Problem Solving, Bentley Systems, Carina Initiatives, National Council of Examiners for Engineering and Surveying, CNA Financial, Google, Brilliant, and Mouser Electronics.
 The Competition Series is divided into four levels: school, chapter, state, and national. Students progress to each level in the competition based on performance at the previous level. As the levels progress, the problems become more challenging. Each level has many rounds, always including a Sprint Round (30 questions, 40 minutes) and a Target Round (4 pairs of harder problems with calculator use, 6 minutes each pair).
 All students are either school-based competitors or non-school competitors ("NSCs"). Most students participate through their schools, starting with a school-level competition. A student whose school is not participating in the Competition Series starts at the chapter level as an NSC, competing individually.
 Coaches of each school select up to 12 students from their school to advance to the chapter competition, with 4 of them competing on the official school team. The rest compete individually.
 All qualifying students compete individually. Students on an official school team also compete as a team. The Countdown Round is optional and can either be used to determine top individuals or as an unofficial round. The top teams and individuals advance to the state competition. The exact number of qualifiers varies by region.
 All qualifying students compete individually. Students on a qualifying school team also compete as a team. The Countdown Round is optional and can either be used to determine top individuals or as an unofficial round. The top 4 individuals qualify for the national competition. The coach of the winning school team is the coach for the state team. Some states have universities within the state that give scholarships to the top individuals of the state.
 Qualifying students and coaches receive an all-expenses-paid trip to the national competition. The competition typically lasts 3–4 days on Mother's Day weekend. The coach of the state team is the supervisor for the team. The students compete individually for the title of national champion. They also compete as a team to represent their state.
 The 12 highest scoring individuals advance to the Countdown Round. The winner of this round is declared the National Champion.
 Scholarships and prizes are awarded to the top individuals and top state teams. In the past, prizes have included trips to Space Camp or to the White House to meet the current President of the United States.
 In addition to the Competition Series program, students can also participate in the National Math Club program.
 The National Math Club program allows schools and non-school groups to start a math club for free. Upon registering, club leaders earn free online access to dozens of games, explorations, and problem sets.
 Clubs that meet at least five times during the program year can achieve Silver Level Status, and clubs that complete a creative and collaborative project can achieve Gold Level Status. Clubs that achieve Silver Level and Gold Level can earn prizes and recognition.
 Each year, Mathcounts awards two types of scholarships to multiple alumni who participated in at least one of the Mathcounts programs during middle school. The Mathcounts Alumni Scholarship is awarded to alumni whose experience in Mathcounts was extremely influential, and the Community Coaching Scholarship is awarded to alumni who start Mathcounts programs at underserved schools.
 In 2011, Mathcounts started the Reel Math Challenge (later renamed to the Math Video Challenge). The Math Video Challenge program allowed students in teams of 4 to create a video that explained the solution to a problem from the Mathcounts School Handbook in a real-world scenario. The program was discontinued in 2023, but a similar video project opportunity is offered through the National Math Club.
 Below is a table documenting each year's winning individual, winning state team and coach, and the location of the national competition.