Intermediate scrutiny, in U.S. constitutional law, is the middle level of scrutiny applied by courts deciding constitutional issues through judicial review. The other levels are typically referred to as rational basis review (least rigorous) and strict scrutiny (most rigorous).
Intermediate scrutiny is met if a regulation involves important governmental interests that are furthered by substantially related means. This should be contrasted with strict scrutiny, the higher standard of review which requires narrowly tailored and least restrictive means to further a compelling governmental interest.
In the context of sex-based classifications, the intermediate scrutiny test applies not only to the federal government, but also to state and local governments (via the Fourteenth Amendment). It also applies to both legislative and executive action whether those actions be of a substantive or procedural nature.
A famous example of intermediate scrutiny comes from Craig v. Boren, 429 US 190 (1976), which was the first case in which a majority of the United States Supreme Court determined that statutory or administrative sex classifications were subject to an intermediate standard of judicial review.
Regarding sex-based classifications, however, the U.S. Supreme Court, in Mississippi University for Women v. Hogan, 458 U.S. 718 (1982), added the requirement that, to be valid, a sex-based classification requires an "exceedingly persuasive justification." In practice, this means that Court examinations of sex-based classifications are closer to strict scrutiny. The Court applied this additional prong in the education context in United States v. Virginia, 518 U.S. 515 (1996) and J.E.B. v. Alabama, 511 U.S. 127 (1994).
Restrictions based on illegitimacy have also been subjected to intermediate scrutiny in the Equal Protection context on the grounds that they involve sex discrimination (see Caban v. Mohammed, 441 U.S. 380 (1979)). Intermediate scrutiny was briefly applied to race-based classifications in affirmative action programs established by the federal government in Metro Broadcasting, Inc. v. FCC (89-453), 497 U.S. 547 (1990). However, Metro Broadcasting only applied to classifications in broadcasting and was overruled by the Supreme Court in Adarand Constructors v. Peña, 515 U.S. 200 (1995), which held that all race-based classifications must be subjected to strict scrutiny.
In the free speech context, intermediate scrutiny applies to regulation that does not directly target speech but has a substantial impact on a particular message. It applies to time, place, and manner restrictions on speech, for example, with the additional requirement of "adequate alternative channels of communication." In other words, if restricting the time, place, or manner of speech means that speech cannot take place at all, the regulation fails intermediate scrutiny. It has been used in "erogenous zoning" cases such as Renton v. Playtime Theatres, Inc., 475 U.S. 41 (1986), that limit the concentration or require concentration of certain types of establishments. It has also been used for other types of content-neutral regulation, as well as for content-neutral speech compulsion. Intermediate scrutiny also applies to regulation of commercial speech, as long as the state interests in regulating relate to fair bargaining. Regulation for other reasons, such as protection of children, are subject to strict scrutiny.
