Rape in the United States is defined by the Department of Justice as "Penetration, no matter how slight, of the vagina or anus with any body part or object, or oral penetration by a sex organ of another person, without the consent of the victim." While definitions and terminology of rape vary by jurisdiction in the United States, the FBI revised its definition to eliminate a requirement that the crime involve an element of force.
A 2013 study found that rape may be grossly underreported in the United States. Furthermore, a 2014 study suggested that police departments may eliminate or undercount rapes from official records in part to "create the illusion of success in fighting violent crime". Based on the available data, 21.8% of American rapes of female victims are gang rapes. For the last reported year, 2013, the prevalence rate for all sexual assaults including rape was 0.1% (prevalence represents the number of victims, rather than the number of assaults since some are victimized more than once during the reporting period). The survey included males and females aged 12+. Since rapes are a subset of all sexual assaults, the prevalence of rape is lower than the combined statistic. Of those assaults, the Bureau of Justice Statistics stated that 34.8% were reported to the police, up from 29.3% in 2004.
In the United States, at the Federal level, the FBI's Uniform Crime Report (UCR) definitions are used when collating national crime statistics from states across the US. The UCR's definition of rape was changed on January 1, 2013 to remove the requirement of force against a female and to include a wider range of types of penetration. The new definition reads:
Penetration, no matter how slight, of the vagina or anus with any body part or object, or oral penetration by a sex organ of another person, without the consent of the victim.
At the state level, there is no uniform legal definition of rape ; instead, each state has their own laws. These definitions can vary considerably, but many of them do not use the term rape anymore, instead using sexual assault, criminal sexual conduct, sexual abuse, sexual battery, etc.
One legal definition, which is used by the United States Armed Forces is found in the United States Uniform Code of Military Justice [Title 10, Subtitle A, Chapter 47X, Section 920, Article 120], defines rape as:
(a) Rape. — Any person subject to this chapter who commits a sexual act upon another person by —