The single requirement to be eligible for Mensa membership is to score in the top 2 percent of people taking an approved intelligence or aptitude test. Eligible candidates need only supply proof of test scores to Mensa and pay membership dues to join the high-intelligence society.
Approved tests include standard IQ tests such as the Stanford-Binet, the Cattell test, the California Test of Mental Maturity and the Weschler Adult and Children scales. Some of the approved aptitude tests are college board exams such as the Graduate Management Admission Test and the Law School Admission Test. PSAT, SAT and ACT scores from year prior to the 1990s are also acceptable, but scores from the years after the exams were revised are not. The same is true for U.S. Army and Navy exams taken after October 1980. Mensa offers testing sessions as well and offers a free practice test on Mensa.org.
A neutral, qualified third party must administer the approved test in its standard test setting, which may be a school, testing center or psychologist's office. Only an official original or notarized copy of the test score documentation is acceptable as proof for membership.
Membership is limited to those people in the 98th percentile or the population or above; this is not the same as scoring a 98 percent or better on a test. For the Cognitive Abiltiies Test and the Standford-Binet, an IQ score of 132 or higher puts a person in the top 2 percent of the population. For the GMAT, the LSAT and the Miller Analogies Test, a 95 percent or higher score on the test qualifies for Mensa.