Definition: A quasi-suspect classification in U.S. Constitution equal protection analysis is a distinction of a certain group of people that falls short of being a suspect classification. A quasi-suspect classification is subject to more heightened scrutiny than a rational basis test, which would presume the challenged law to be valid. The basic recognized quasi-suspect classifications are gender and illegitimacy.
A law or regulation whose discrimination involves a quasi-suspect class is subject to intermediate scrutiny. Intermediate scrutiny is a standard of judicial review below strict scrutiny but above rational basis review. Intermediate scrutiny asks whether the law furthers an important state interest and whether the quasi-suspect classification is related to serving that interest.
Gender is a quasi-suspect class. Some Supreme Court justices have argued that gender distinctions should be suspect classifications and that sex-based discrimination should be subject to strict scrutiny along with the suspect classes of race and national origin.