Most states have two parallel sets of sexual assault statutes. One set punishes sexual assaults involving sexual penetration that has greater penalties. The other set punishes sexual assaults involving sexual contact without sexual penetration that has smaller penalties but otherwise the same elements of the offense.
Usually, almost every offense which is a crime when it involves sexual penetration is also a crime when it involves sexual contact but not sexual penetration, with the fairly frequent exception of statutory rape offenses that cover an adolescent victim who is below the age of consent but post-pubescent (with the statute itself setting specific age thresholds that vary from jurisdiction to jurisdiction).
Often, even when statutory rape of an adolescent (i.e. sex with consent by an adolescent under the age of consent) itself is a relatively minor crime, often a misdemeanor, and is rarely prosecuted to the full extent of the law, child prostitution or attempted child prostitution with the same victim is often a very serious offense, and child pornography offenses often also carry serious penalties when the "child" is under the age of eighteen, even when the sexual act filmed or photographed itself is of people who are above the age of consent and are legally having consensual sex.
In many states, sex with someone in a position of authority over the victim is a crime without regard to consent, much like a statutory rape offense, but without regard to age. In some states there would be a parallel sexual contact offense, and in some states there would not be one.
The name of the offenses varies considerably from jurisdiction to jurisdiction. Sometimes they are different degrees of the same offense, sometimes they are offenses with different names, and the names used varies quite a bit.
Also, even when an arguable sexual contact offense is not a sex offense, it would almost always be some form of non-sexual criminal assault offense.
For example, Colorado has sexual assault related crimes called sexual assault at Colo. Rev. Statutes § 18-3-402 (involving sexual penetration and including two grades of statutory rape, and including cases where "the victim is in custody of law or detained in a hospital or other institution and the actor has supervisory or disciplinary authority over the victim and uses this position of authority to coerce the victim to submit, unless the act is incident to a lawful search" and cases where "the actor, while purporting to offer a medical service, engages in treatment or examination of a victim for other than a bona fide medical purpose or in a manner substantially inconsistent with reasonable medical practices"), a parallel crime called unlawful sexual contact at Colo. Rev. Statutes § 18-3-404 (not involving sexual penetration, including cases where "the victim is in custody of law or detained in a hospital or other institution and the actor has supervisory or disciplinary authority over the victim and uses this position of authority to coerce the victim to submit, unless the act is incident to a lawful search" and cases where "the actor, while purporting to offer a medical service, engages in treatment or examination of a victim for other than a bona fide medical purpose or in a manner substantially inconsistent with reasonable medical practices"), a crime called sexual assault on a child at Colo. Rev. Statutes § 18-3-405, sexual assault on a child by one in a position of trust at Colo. Rev. Statutes § 18-3-405.3, internet sexual exploitation of a child at Colo. Rev. Statutes § 18-3-405.4, sexual assault on a client by a psychotherapist at Colo. Rev. Statutes § 18-3-405.5, incest at Colo. Rev. Statutes § 18-6-301, criminal extortion at Colo. Rev. Statutes § 18-3-207, second degree kidnapping at Colo. Rev. Statutes § 18-3-302, aggravated incest at Colo. Rev. Statutes § 18-6-302, human trafficking for sexual servitude at Colo. Rev. Statutes § 18-3-504, sexual exploitation of a child at Colo. Rev. Statutes § 18-6-403, procurement of a child for sexual exploitation at Colo. Rev. Statutes § 18-6-404; soliciting for child prostitution at Colo. Rev. Statutes § 18-7-402, pandering of a child at Colo. Rev. Statutes § 18-7-403, procurement of a child at Colo. Rev. Statutes § 18-7-403.5, keeping a place of child prostitution at Colo. Rev. Statutes § 18-7-404; pimping of a child at Colo. Rev. Statutes § 18-7-405, inducement of child prostitution at Colo. Rev. Statutes § 18-7-405.5, patronizing a prostituted child at Colo. Rev. Statutes § 18-7-406, internet luring of a child at Colo. Rev. Statutes § 18-3-306, obscenity at Colo. Rev. Statutes § 18-7-102, posting a private image for harassment at Colo. Rev. Statutes § 18-7-107, posting a private image for pecuniary gain at Colo. Rev. Statutes § 18-7-108, posting, possession, or exchange of a private image by a juvenile at Colo. Rev. Statutes § 18-7-109, prostitution at Colo. Rev. Statutes § 18-7-201, soliciting for prostitution at Colo. Rev. Statutes § 18-7-202, pandering at Colo. Rev. Statutes § 18-7-203, keeping a place of prostitution at Colo. Rev. Statutes § 18-7-204, patronizing a prostitute at Colo. Rev. Statutes § 18-7-205, pimping at Colo. Rev. Statutes § 18-7-206, and prostitute making display at Colo. Rev. Statutes § 18-7-207, public indecency at Colo. Rev. Statutes § 18-7-301, indecent exposure at Colo. Rev. Statutes § 18-7-302, sexual conduct in a correctional institution at Colo. Rev. Statutes § 18-7-701, criminal invasion of privacy at Colo. Rev. Statutes § 18-7-801, harassment at Colo. Rev. Statutes § 18-9-111, hazing at Colo. Rev. Statutes § 18-9-124, cruelty to animals at Colo. Rev. Statutes § 18-9-202, and violations of the Colorado Organized Crime Control Act at Colo. Rev. Statute § 18-17-101, et seq.
If found guilty, what would a typical punishment be in the US?
In a system in which there are several classes of felonies and several classes of misdemeanors, usually sexual contact offenses are one to three offense classes below the sexual penetration offense with the same elements.
For example, if unaggravated sexual penetration without consent is the second lowest grade of felony, unaggravated sexual contact without consent is typically the lowest grade of felony or the highest grade of misdemeanor.
A highly aggravated sexual assault with penetration offense is often punishable by decades in prison. An unaggravated sexual contact without consent offense may be punishable by up to six to twelve months in jail or a long period of probation. The offenses are too varied by jurisdiction and crime details to summarize easily. Aggravated rape is a death penalty offense in U.S. military justice although the U.S. Supreme Court has held that the imposition of the death penalty (at least in cases where the victim is not a child) is unconstitutional. Some states declare in their statutes that the aggravated rape of a child is a death penalty offense although the constitutionality of those statutes has not been tested in court and no one has been executed for such an offense since the death penalty was reinstated in the 1970s in the U.S.
Most sex offenses in the U.S. of all types, including both sexual contact offenses, sexual penetration offenses, and even offenses involving no contact at all, such being a peeping tom, also require to convicted defendant to register as a sex offender, either for a long period of time or for life, which is a quite severe and separate punishment in addition to the incarceration and/or fine and court costs and surcharges involved.
In the case of child sex offenses and some repeat rape offenders, even after a term of incarceration is fully served, the state may seek to have the offender detained indefinitely civilly to protect the public until it is determined that the offender is no longer a threat, which rarely happens in practice.