Bigamy is the crime of marrying someone while you are already legally married to another person. Every U.S. state treats it as a criminal offense, and the second marriage itself is almost always legally void from the moment the ceremony takes place. That dual consequence — a possible criminal record and a marriage the law refuses to recognize — is what makes bigamy different from other marital disputes.
The Two Elements That Make a Marriage Bigamous
A bigamy charge requires two things: a valid existing marriage and a new marriage ceremony. If your first marriage was legally valid, or voidable but never actually annulled, and you go through a second marriage ceremony without first ending the first one through divorce or annulment, you’ve committed bigamy. The second ceremony itself typically completes the offense. You don’t need to live with or consummate the second marriage for the charge to apply.
A marriage that was void from the start changes this analysis. If your first marriage was never legally valid — for example, because it was incestuous — then marrying again isn’t technically bigamy, since there was no valid prior marriage to violate. The distinction between void and voidable matters. A voidable marriage, meaning one with a defect that could support an annulment such as fraud or duress, still counts as a real marriage until a court officially annuls it.
Bigamy, Polygamy, and Polyamory Are Not the Same
People use these terms interchangeably, but they describe different things. Bigamy refers specifically to going through a marriage ceremony with a second person while your first marriage is still active. Polygamy is the broader practice of having multiple spouses at once, whether that means two or twenty. Bigamy is essentially a subset of polygamy where the number happens to be two. Both are illegal throughout the United States.
Polyamory is something different. It describes consensual romantic relationships involving more than two people, but nobody is trying to obtain multiple marriage licenses. Because polyamory doesn’t involve additional legal marriages, it doesn’t violate bigamy or polygamy laws.
Criminal Penalties
The severity of a bigamy charge varies dramatically from state to state. In roughly half the country, bigamy is classified as a felony. In others, it’s a misdemeanor. One state recently reduced simple bigamy to an infraction, the equivalent of a traffic ticket, though the penalty escalates sharply if the bigamy involves fraud, coercion, or other crimes. Fines for a bigamy conviction can range from a few hundred dollars to $150,000 at the high end. Prison sentences range from no jail time at all to ten years in the most severe jurisdictions.
As a practical matter, bigamy prosecutions are relatively uncommon. Prosecutors tend to prioritize cases involving fraud, abuse, or immigration violations over situations where someone simply failed to finalize a divorce before remarrying. But uncommon doesn’t mean never, and a conviction creates a permanent criminal record regardless of the sentence.
The Second Marriage Is Legally Void
The civil fallout from bigamy is often more consequential than the criminal penalties. A bigamous second marriage is generally void from the start. Legally, it never existed. That isn’t just a technicality. It means the second spouse has no right to spousal support, no automatic inheritance rights, no claim to property division under divorce law, and no ability to make medical decisions as a spouse. The first marriage remains valid and unaffected.
Even though a bigamous marriage is void by operation of law, you typically still need a court order to make that official. Without a formal annulment or declaration of invalidity, the marriage stays on the books. Government agencies, insurers, and financial institutions rely on court records, not legal theory. Getting the court order also clarifies property rights and any obligations between the parties.1Social Security Administration. GN 00305.125 – Void Marriages
One wrinkle catches people off guard. Annulling the first marriage after the fact doesn’t retroactively validate the second one. If the first marriage is later annulled or the first spouse dies, the second marriage doesn’t become valid by default. An entirely new ceremony would be needed to establish a legal marriage with the second person.
Protection for a Spouse Who Didn’t Know
Not everyone in a bigamous marriage knew what they were getting into. The person who had no idea their partner was already married, sometimes called a putative spouse, gets some legal protection in a number of states. The putative spouse doctrine exists to prevent someone who married in genuine good faith from losing everything when the marriage turns out to be void.
In states that recognize this doctrine, a putative spouse can claim property rights similar to those of a legal spouse, including a share of assets acquired during the relationship and, in some jurisdictions, spousal support. The key requirement is good faith: you must have genuinely and reasonably believed the marriage was valid. If you knew or should have known your partner was already married, the doctrine doesn’t apply.
Not every state recognizes putative spouse rights, and the specific protections vary among those that do. Some grant the same property rights as a legal spouse. Others offer more limited equitable relief. The protections available depend entirely on where you live.
What Happens to the Children
Children born during a bigamous marriage are generally treated as legitimate regardless of their parents’ marital status. This is one area where the law prioritizes the child’s welfare over the parents’ legal problems. Children of a void marriage typically retain the same rights as children of a valid one, including financial support from both parents, custody and visitation rights, and inheritance rights.
Child support obligations exist independently of whether the parents’ marriage was valid. A parent cannot avoid paying child support by arguing that the marriage was bigamous and therefore void. Courts consistently hold that the parent-child relationship and its financial obligations are separate from the validity of the marriage.
Immigration and Military Consequences
Bigamy can trigger federal consequences that go well beyond state criminal penalties. If someone enters into a marriage to obtain immigration benefits and that marriage turns out to be bigamous, the stakes multiply. Under federal law, knowingly entering a marriage to evade immigration provisions carries up to five years in prison and fines up to $250,000.2Office of the Law Revision Counsel. 8 USC 1325 – Improper Entry by Alien A person found to have committed fraud or willful misrepresentation in seeking immigration benefits also faces inadmissibility, meaning they can be barred from obtaining visas, green cards, or other immigration benefits in the future.3Office of the Law Revision Counsel. 8 USC 1182 – Inadmissible Aliens
If USCIS discovers that a marriage-based green card petition involves bigamy, the petition will be denied and the applicant may face deportation proceedings. The foreign national involved may be permanently barred from reentering the country. U.S. citizens who knowingly participate in a fraudulent marriage can face conspiracy charges carrying the same five-year prison term.
Military service members face additional exposure. Bigamy can be prosecuted under the Uniform Code of Military Justice, and a conviction can end a military career. The military takes a particularly dim view of bigamy because service members’ marital status affects housing allowances, healthcare benefits, and survivor benefits, all funded by the federal government.
Possible Defenses
Several circumstances can provide a defense to a bigamy charge, though the strength of these defenses varies significantly by jurisdiction.
- Good faith belief the prior marriage ended. If you genuinely and reasonably believed your divorce was final before remarrying, some states treat this as a valid defense. Perhaps your attorney told you the divorce was complete, or you received documents that appeared to finalize it. Not every state accepts this defense. Some treat bigamy as a strict liability offense, meaning your mental state and honest beliefs are irrelevant.
- Prolonged absence of a spouse. Most states have a provision allowing remarriage when a spouse has been absent and unheard from for a specified number of years, typically five to seven. The law presumes the missing spouse is dead after that period, and remarriage doesn’t constitute bigamy. Some states require you to have made reasonable efforts to locate the missing spouse.
- Void prior marriage. If your first marriage was void from its inception rather than merely voidable, no valid prior marriage existed and a bigamy charge can’t stand. A marriage that was only irregular or voidable still counts as a valid marriage until a court says otherwise.
What to Do If You Discover a Bigamous Marriage
If you learn that your spouse was already married when they married you, consult a family law attorney before doing anything else. Many people go straight to the police, which can complicate the civil side. An attorney can explain what property rights you may have, especially under the putative spouse doctrine if your state recognizes it, whether you need a formal annulment, and how to protect your interests in any shared assets or debts before a criminal case makes your spouse uncooperative or unemployable.
Gather documentation: your marriage certificate, any records of your spouse’s prior marriage, and evidence of assets acquired during the relationship. If immigration benefits were involved, the situation becomes urgent because of the federal penalties. Filing for a formal annulment or declaration of invalidity is typically necessary even though the marriage is legally void. Without that court order, the marriage remains on public record and can cause complications with taxes, benefits, and any future marriage of your own.