All 50 States Ban Incest—But New Jersey and Rhode Island Allow It Between Consenting Adults
Every US state has incest laws, but New Jersey and Rhode Island do not criminalize sexual relations between consenting adults (age 18+ in NJ, 16+ in RI)—though incestuous marriage remains illegal in both states. Ohio restricts incest prosecutions to parent-child relationships only. All other 47 states criminalize incest between adults regardless of consent.
Definitions vary: most prohibit sexual activity between parents-children, siblings, grandparents-grandchildren, and often aunts/uncles with nieces/nephews. Penalties range from Delaware’s 1-year maximum to life imprisonment in Montana, Idaho, Nevada, Colorado, and Michigan. Parent-child incest carries the harshest penalties nationwide.
Do All States Have Incest Laws?
Yes. All 50 states, the District of Columbia, and US territories have codified incest prohibitions. However, enforcement and scope differ dramatically.
Three States With Notable Exceptions:
New Jersey: Incest between consenting adults 18+ is not a criminal offense. However, incest with minors is prosecuted as aggravated sexual assault (under 16) or sexual assault (16-17). Incestuous marriage is prohibited.
Rhode Island: Incest between consenting adults 16+ (the age of consent) is decriminalized. The state repealed its criminal incest statute but maintains a ban on incestuous marriage.
Ohio: Criminalizes incest only when involving parental figures (parent-child, stepparent-stepchild). Adult siblings, aunts/uncles with nieces/nephews, and other relationships are not prosecuted.
All Other 47 States: Criminalize incest between consenting adults regardless of age or consent, with felony penalties in nearly all jurisdictions.
What Relationships Are Prohibited?
Most states prohibit sexual activity between:
Nearly Universal Prohibitions:
- Parent and child (biological, adoptive, or step)
- Grandparent and grandchild
- Brother and sister (whole blood or half-blood)
Common Additional Prohibitions (varies by state):
- Aunt and nephew
- Uncle and niece
- Stepparent and stepchild
- Adoptive parent and adopted child
- In-laws (in some states)
- First cousins (in about half of states)
State Variations:
California Penal Code 285 prohibits sexual intercourse between persons “within the degrees of consanguinity within which marriages are declared by law to be incestuous and void” age 14+.
Texas Penal Code 25.02 prohibits sexual conduct between:
- Ancestors and descendants (parent-child, grandparent-grandchild)
- Siblings or half-siblings
- Uncles/aunts with nephews/nieces
- Stepparents with stepchildren (if under 18 and not legally married)
Montana Code 45-5-507 extends prohibitions to nephews/nieces and any stepson/stepdaughter, with consent defenses for steprelationships under specific conditions.
Michigan Compiled Laws 750.520e covers relatives “by blood or affinity to the third degree,” creating broader family coverage than most states.
Criminal Penalties by State
Penalties vary from 1 year to life imprisonment depending on state, relationship type, victim age, and conduct involved.
Lowest Penalties:
- Delaware: Up to 1 year maximum (lowest in nation)
- Virginia: Class 1 misdemeanor for most relationships; Class 5 felony for parent-child (1-10 years); Class 3 felony if victim 13-17 (5-20 years)
Moderate Penalties (5-15 years maximum):
- California: Up to 3 years state prison plus $10,000 fine; sex offender registration required
- Florida: Third-degree felony, up to 5 years prison, $5,000 fine, sex offender registration
- Tennessee: Class C felony
- Washington: Up to 10 years for sexual intercourse (Class B felony); up to 5 years for sexual contact (Class C felony)
Severe Penalties (20+ years):
- Texas: 2-10 years for most incest; 2-20 years for parent-child or grandparent-grandchild incest
- Massachusetts: Up to 20 years
- Oregon: Up to 20 years
- Georgia: Up to 30 years
- Wisconsin: Up to 40 years
Life Imprisonment Maximum:
- Montana: Life or up to 100 years; 4-100 years if victim under 16; mandatory 100 years if victim under 12 and offender 18+
- Idaho: Life imprisonment possible
- Nevada: Life imprisonment possible
- Colorado: Life imprisonment possible; penalties increase when victim under 21
- Michigan: Life imprisonment possible
Texas Example (Penal Code 25.02):
- General incest: Second-degree felony (2-10 years)
- Parent-child incest: Second-degree felony (2-20 years)
- Maximum fine: $10,000
Louisiana Example (Rev. Stat. 14:89):
- Parent-child: 15 years
- Uncle-niece or aunt-nephew: 5 years
How State Laws Differ
Definition of Prohibited Conduct
Sexual Intercourse Only: Georgia, Illinois require penetration
Broader Sexual Conduct: Michigan, Washington prohibit sexual contact including touching
Marriage Alone Sufficient: California, Florida criminalize incestuous marriage even without sexual activity
Age Requirements
California: Applies to persons 14+ (minors under 14 are victims, not perpetrators under People v. Tobias)
Alaska: Applies to persons 18+
Most states: Apply to all ages but treat minors as victims when adults are involved
Knowledge Requirement
Most states require defendants knew of the family relationship. Prosecutors must prove the defendant was aware they were related by blood or marriage/adoption.
Covered Relationships
Narrow (Ohio): Parent-child only
Moderate (Most states): Parents, children, siblings, grandparents, grandchildren
Broad (Montana, Michigan): Extend to nephews/nieces, stepchildren, third-degree relatives by affinity
Penalty Structure
Single Penalty (Florida, Oregon): One classification regardless of relationship or circumstances
Tiered by Relationship (Louisiana, Texas): Harsher penalties for closer relationships (parent-child vs. uncle-niece)
Tiered by Age (Colorado, Georgia, Montana): Increased penalties when victim is minor
Tiered by Conduct (Washington, Michigan): Different penalties for intercourse vs. sexual contact
Civil Implications
Beyond criminal prosecution, incest creates civil consequences:
Marriage Invalidity: Incestuous marriages are void ab initio (void from the beginning) in all states. Children born of such marriages may still be considered legitimate in many jurisdictions.
Child Custody: Incest convictions result in loss of parental rights and termination of custody.
Sex Offender Registration: Many states (California, Florida, others) require convicted offenders to register as sex offenders, creating lifelong reporting requirements and restrictions on residence and employment.
Immigration Consequences: Incest convictions constitute crimes of moral turpitude, triggering deportation for non-citizens and inadmissibility bars.
Professional Licensing: Convictions can result in revocation or denial of professional licenses (medical, legal, teaching, childcare).
How Are These Laws Enforced?
Incest prosecutions face unique challenges:
Underreporting: Most incest cases between consenting adults are never reported to authorities. The US Department of Justice estimates thousands of cases go unreported annually.
Discovery Methods: Cases typically surface when:
- One party files complaint (often the non-adult victim in parent-child cases)
- Other family member reports (often the non-offending parent discovers parent-adult child incest)
- Pregnancy or genetic testing reveals relationship
- Investigation of related crimes (child abuse, domestic violence)
Prosecutorial Discretion: Prosecutors may charge under incest statutes or related crimes:
- Rape (if non-consensual)
- Statutory rape (if victim under age of consent)
- Child molestation (if victim is minor)
- Sexual assault
- Child abuse
Evidence Requirements: Prosecutors must prove:
- Family relationship existed (birth certificates, DNA testing, adoption records)
- Prohibited sexual conduct occurred (victim testimony, physical evidence, confessions)
- Defendant knew of relationship (often presumed for close relatives like siblings or parents)
Defenses: Common defenses include:
- Lack of knowledge of family relationship (particularly for separated-at-birth siblings or undisclosed adoptions)
- False accusations (family member lying due to grudge)
- Insufficient evidence (no physical evidence, conflicting testimony)
- Constitutional challenges (right to privacy, though rarely successful)
State-by-State Overview
States That Criminalize All Adult Incest: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, Florida, Georgia, Hawaii, Idaho, Illinois, Indiana, Iowa, Kansas, Kentucky, Louisiana, Maine, Maryland, Massachusetts, Michigan, Minnesota, Mississippi, Missouri, Montana, Nebraska, Nevada, New Hampshire, New Mexico, New York, North Carolina, North Dakota, Oklahoma, Oregon, Pennsylvania, South Carolina, South Dakota, Tennessee, Texas, Utah, Vermont, Virginia, Washington, West Virginia, Wisconsin, Wyoming
Exceptions:
- New Jersey: Adult incest (18+) not criminal; minor incest prosecuted as sexual assault
- Rhode Island: Adult incest (16+) not criminal; incestuous marriage prohibited
- Ohio: Only parent-child incest criminalized; other adult relationships not prosecuted
District of Columbia: Criminalizes incest between close relatives with felony penalties.
Recent Legal Developments
Rhode Island (Pre-2025): Repealed criminal incest statute but maintained marriage prohibitions, effectively decriminalizing adult consensual incest while preventing legal recognition.
California Legislative Updates: 2005 Legislature partially overturned People v. Tobias to permit criminal liability for minors 14+ in some circumstances (Stats. 2005, Ch. 477, Sec. 1).
Expanded Sex Offender Registration: Multiple states expanded registration requirements to include incest convictions, creating lifetime monitoring for offenders.
Federal Jurisdiction: Federal law may apply when incest occurs on federal property (military bases, national parks) or involves interstate travel. Federal penalties often exceed state penalties.
What Legal Experts Say
Legal scholars identify several rationales for incest prohibitions:
Genetic Concerns: Offspring of closely related individuals face significantly higher rates of genetic disorders and birth defects.
Family Stability: Incest disrupts family structures and creates confusion about familial roles and responsibilities.
Power Imbalances: Parent-child and adult-minor incest involve inherent power imbalances making true consent impossible.
Child Protection: Even in consensual adult cases, laws protect against grooming that may have begun when victim was minor.
Social Taboo: Incest violates deeply held social and cultural norms across virtually all societies.
Constitutional Challenges: Defendants occasionally challenge incest laws as violations of privacy rights or equal protection. Courts have consistently upheld incest statutes as valid exercises of state police powers protecting public health and morals.
Key Takeaways
- All 50 States Have Laws: Every state prohibits some form of incest, but definitions and enforcement vary dramatically
- New Jersey and Rhode Island Exception: Only two states decriminalize adult consensual incest while prohibiting incestuous marriage
- Ohio’s Narrow Scope: Restricts prosecution to parental figures only, not siblings or other relatives
- Parent-Child Carries Harshest Penalties: All states impose most severe punishments for parent-child incest regardless of victim’s age
- Wide Penalty Range: 1 year (Delaware) to life imprisonment (Montana, Idaho, Nevada, Colorado, Michigan)
- Relationship Definitions Vary: Some states cover only lineal relatives (parents, children, grandparents); others extend to uncles, aunts, nephews, nieces, and third-degree relatives
- Sex Offender Registration: Many states require registration, creating lifetime consequences beyond prison time
Frequently Asked Questions
Q: Is incest legal anywhere in the United States?
A: Consensual adult incest is not criminally prosecuted in New Jersey (18+) and Rhode Island (16+), though incestuous marriage remains illegal. Ohio only criminalizes parent-child incest. All other 47 states fully criminalize adult incest.
Q: What states have the harshest incest penalties?
A: Montana, Idaho, Nevada, Colorado, and Michigan allow life imprisonment. Georgia (30 years), Wisconsin (40 years), Texas, Massachusetts, Virginia, and Oregon (20 years) also impose severe sentences.
Q: Can first cousins have sexual relationships?
A: Approximately half of US states permit first cousin marriage and sexual relationships. Other states prohibit first cousin marriage but may not criminally prosecute sexual activity. Check specific state statutes.
Q: What if I didn’t know we were related?
A: Most states require prosecutors to prove you knew about the family relationship. Lack of knowledge can be a valid defense, particularly for adopted individuals or separated-at-birth siblings who later meet.
Q: Is stepparent-stepchild incest illegal?
A: Most states include steprelationships in incest prohibitions, especially when the stepchild is a minor. Some states (Montana) provide consent defenses for adult steprelationships under specific conditions.
Q: What happens if incest results in pregnancy?
A: The pregnancy itself doesn’t create additional criminal charges, but may serve as evidence of the underlying incest crime. Children born of incestuous relationships are generally considered legitimate despite the void marriage.
Q: Do I have to register as a sex offender if convicted of incest?
A: Many states (California, Florida, others) require sex offender registration for incest convictions. Requirements vary by state and may depend on victim’s age and relationship. Registration creates lifetime reporting obligations and residence/employment restrictions.
This article provides legal information about incest laws across US states but does not constitute legal advice. Individuals facing incest-related charges should consult licensed criminal defense attorneys in their jurisdictions.
About the Author
Sarah Klein, JD, is a licensed attorney and legal content strategist with over 12 years of experience across civil, criminal, family, and regulatory law. At All About Lawyer, she covers a wide range of legal topics — from high-profile lawsuits and courtroom stories to state traffic laws and everyday legal questions — all with a focus on accuracy, clarity, and public understanding.
Her writing blends real legal insight with plain-English explanations, helping readers stay informed and legally aware.
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