In the United States, every state and the District of Columbia have some form of incest prohibition. However, individual statutes vary widely. In all states, close blood-relatives that fall under the incest statutes include father, mother, grandfather, grandmother, brother, sister, aunt, uncle, niece, nephew, and in some states, first cousins. Many states also apply incest laws to non-blood relations including stepparents, step siblings, and in-laws. Some states even extend this to first cousins.

The punishment also varies between states. Depending on the facts of the case, it could be just a misdemeanor (if illegal), or it could be up to 20 years in prison. And if one person is a minor, there could also be other charges files, from sexual misconduct up to statutory rape.

The following are examples of punishments for incest followed by various states:

In California, pursuant to Cal Pen Code § 285, “persons being within the degrees of consanguinity within which marriages are declared by law to be incestuous and void, who intermarry with each other, or who being 14 years of age or older, commit fornication or adultery with each other, are punishable by imprisonment in the state prison.”

In Delaware, pursuant to 11 Del. C. § 766, “incest is a class A misdemeanor and is an offense within the original jurisdiction of the Family Court.”

In Washington, pursuant to DCD.C. Code § 22-1901, “if any person in the District related to another person within and not including the fourth degree of consanguinity, computed according to the rules of the Roman or civil law, shall marry or cohabit with or have sexual intercourse with such other so-related person, knowing him or her to be within said degree of relationship, the person so offending shall be deemed guilty of incest, and, on conviction thereof, shall be punished by imprisonment for not more than 12 years.”

In Georgia, pursuant to O.C.G.A. § 16-6-22, “a person convicted of the offense of incest shall be punished by imprisonment for not less than ten nor more than 30 years; provided, however, that any person convicted of the offense of incest under this subsection with a child under the age of 14 years shall be punished by imprisonment for not less than 25 nor more than 50 years. Any person convicted under this Code section of the offense of incest shall, in addition, be subject to the sentencing and punishment provisions of Code Section 17-10-6.2.”

In Idaho, pursuant to Idaho Code § 18-6602, “persons being within the degrees of consanguinity within which marriages are declared by law to be incestuous and void, who intermarry with each other, or who commit fornication or adultery with each other, are punishable by imprisonment in the state prison for a term not to exceed life.”

In Louisiana, pursuant to La. R.S. 14:78, “whoever commits incest, where the crime is between an ascendant and descendant, or between brother and sister, shall be imprisoned at hard labor for not more than fifteen years.  (2) Whoever commits incest, where the crime is between uncle and niece, or aunt and nephew, shall be fined not more than one thousand dollars, or imprisoned, with or without hard labor, for not more than five years, or both.”

In Massachusetts, pursuant to ALM GL ch. 272, § 17, persons within degrees of consanguinity within which marriages are prohibited or declared by law to be incestuous and void, who intermarry or have sexual intercourse with each other, or who engage in sexual activities with each other, including but not limited to, oral or anal intercourse, fellatio, cunnilingus, or other penetration of a part of a person’s body, or insertion of an object into the genital or anal opening of another person’s body, or the manual manipulation of the genitalia of another person’s body, shall be punished by imprisonment in the state prison for not more than 20 years or in the house of correction for not more than 21/2 years.