Yes, incest is illegal in Texas. Under Texas Penal Code Section 25.02, sexual intercourse or oral or anal sexual contact between close relatives is a felony, and a conviction can bring 2 to 20 years in prison plus lifetime sex offender registration. The statute’s definition of “relative” is broader than most people expect, reaching stepchildren, stepparents, and first cousins in addition to blood family.1State of Texas. Texas Code Penal – Prohibited Sexual Conduct
Which Relationships the Law Covers
Section 25.02 lists six categories of prohibited relationships:
- Ancestors and descendants by blood or adoption (parents, grandparents, children, grandchildren).
- Current or former stepparents and stepchildren. The prohibition does not end when the marriage that created the step-relationship ends.
- A parent’s brother or sister by whole or half blood (aunts and uncles).
- Brothers and sisters of the whole or half blood, or by adoption.
- The children of a brother or sister (nieces and nephews), by whole or half blood or adoption.
- First cousins by whole or half blood or adoption.
The step-relative rule surprises people. A stepparent who divorces the child’s biological parent remains permanently prohibited from sexual contact with the former stepchild.1State of Texas. Texas Code Penal – Prohibited Sexual Conduct
Consent is not a defense. Texas prohibits the listed conduct regardless of whether both adults agreed, and both participants can be charged.
Second-Degree or Third-Degree Felony
The offense splits into two felony levels based on how close the relationship is.
When the conduct is between a parent and child, or a grandparent and grandchild, by blood or adoption, it is a second-degree felony punishable by 2 to 20 years in prison and a fine of up to $10,000.2State of Texas. Texas Code Penal – Second Degree Felony
Every other relationship on the list, including stepparents, stepchildren, siblings, aunts, uncles, nieces, nephews, and first cousins, produces a third-degree felony. That range is 2 to 10 years in prison and a fine of up to $10,000.3State of Texas. Texas Code Penal – Third Degree Felony
Lifetime Sex Offender Registration
A conviction under Section 25.02 triggers mandatory sex offender registration under Chapter 62 of the Texas Code of Criminal Procedure. The Texas Department of Public Safety classifies prohibited sexual conduct as a Tier III offense, meaning the duty to register lasts for life.4Texas Department of Public Safety. Texas Length of Duty to Register Compared to SORNA
Registered offenders must provide personal information including home address, employment, and vehicle information, verify it periodically with local law enforcement, and appear in a publicly accessible registry. For many people, the registration outlasts and outweighs the prison term.
The Knowledge Element
To convict, prosecutors must prove the defendant knew the other person was a relative. That knowledge is not presumed. It matters in the uncommon situation where biological relatives were separated at birth or otherwise had no reason to know they were related.
Marriage Between Relatives Is Void
Separate from the criminal statute, Texas Family Code Section 6.201 declares marriages between close relatives void from the start. The list covers ancestors and descendants, siblings including half-siblings, and aunts or uncles with nieces or nephews, all by blood or adoption. A void marriage is treated as though it never legally existed, which affects property rights, inheritance, and children born during the relationship.5State of Texas. Texas Code Family – Consanguinity
The marriage prohibition is narrower than the criminal one. It does not list stepparents, stepchildren, or first cousins. But Section 25.02 still applies to those relationships, so a marriage that Texas permits does not shield the participants from felony charges.
When a Child Is Involved, Everyone Has to Report
Texas Family Code Section 261.101 requires any person with reasonable cause to believe a child has been abused or neglected to report it immediately. This duty is not limited to professionals. It applies to everyone in Texas.6State of Texas. Texas Code Family – Persons Required to Report; Time to Report
Knowingly failing to report suspected child abuse is a Class A misdemeanor, punishable by up to one year in jail and a fine of up to $4,000. Intentional concealment can raise the offense to a state jail felony.7State of Texas. Texas Code Family – Failure to Report; Penalty
Consequences That Outlast the Sentence
Parental rights are among the first casualties. Under Texas Family Code Section 161.007, a court can terminate parental rights when a child was conceived through sexual abuse or incest, and a conviction makes termination proceedings much more likely to succeed.8Texas State Law Library. Can I Terminate My Parental Rights
Employment narrows sharply. Texas licensing boards can revoke or deny professional licenses based on felony convictions involving sexually violent offenses, which effectively closes teaching, healthcare, childcare, and law enforcement. Outside licensed work, the combination of a felony record and sex offender registration turns ordinary background checks into hiring barriers.
Housing is a continuing problem. Landlords screen for sex offender status, and local ordinances may impose residency restrictions. Because the registry is public, community and social consequences follow the person indefinitely.
Federal Charges When Conduct Crosses State Lines
Texas is not the only jurisdiction that may prosecute. Under 18 U.S.C. Section 2423, transporting a person under 18 across state lines with the intent that they engage in any sexual activity that would be a criminal offense carries a mandatory minimum of 10 years in federal prison and a maximum of life. An adult who travels in interstate commerce with the intent to engage in illicit sexual conduct faces up to 30 years. Attempts and conspiracies carry the same penalties as completed offenses, and federal charges can be brought on top of state charges.9Office of the Law Revision Counsel. 18 U.S. Code 2423 – Transportation of Minors
Defenses That Come Up
The knowledge element is the most direct target. If the defendant genuinely did not know the other person was a relative, the prosecution’s case can fail on that ground alone.
Other defenses go to the evidence: witness credibility, forensic disputes, or an argument that the conduct did not meet the statutory definition of sexual intercourse or oral or anal contact. In step-relative cases, the defense may argue that the specific relationship falls outside the statute’s listed categories.
Constitutional challenges based on privacy rights between consenting adults have not gained traction in Texas courts, which have treated the state’s interest in preventing exploitation within family power dynamics as a sufficient basis for the prohibition. Given the prison exposure and the lifetime registration that follows a conviction, anyone facing a Section 25.02 charge needs experienced criminal defense counsel from the start.