The penalty for adultery depends almost entirely on where you live and what you do for a living. Criminal charges are still technically possible in about 16 states but almost never filed. The real costs usually land in divorce court, where infidelity can shrink alimony and shift how marital property is divided. In a handful of states, your spouse’s partner can also be sued personally. And if you serve in the military, adultery can end your career through a court-martial, non-judicial punishment, or administrative discharge.
Criminal Penalties Are Real on Paper, Rare in Practice
Roughly 16 states still classify adultery as a criminal offense. Most treat it as a misdemeanor. Three states treat it as a felony, with penalties ranging from a $500 fine on the low end to up to five years in prison and a $10,000 fine on the high end. Another dozen or so states never formally repealed older adultery statutes, though those laws sit dormant.
Actual prosecutions are extraordinarily rare. District attorneys treat these cases as a poor use of limited resources, and when adultery charges do appear, they usually ride along with other criminal conduct rather than standing alone. The direction of the law is toward repeal: New York eliminated its adultery statute in November 2024, continuing a slow clearing of these laws from the books.1Justia Law. Lawrence v. Texas, 539 U.S. 558 (2003)
So the honest answer on criminal exposure for a civilian: possible in theory, almost never real.
What Adultery Costs in Divorce
This is where most people actually feel the penalty. Whether your state is no-fault, fault-based, or a hybrid, infidelity can move the numbers in a divorce and, in narrow situations, affect custody.
Alimony
Many states let judges weigh marital misconduct when setting the amount and length of spousal support. A spouse proven to have committed adultery may receive reduced alimony or none at all. Adultery is one factor among many, though. Courts still focus most on the supported spouse’s financial need and the paying spouse’s ability to pay, so infidelity alone rarely drives the whole decision.
Property Division and Dissipation of Assets
Adultery by itself usually does not change how courts divide marital property. Equitable distribution turns on the length of the marriage, each spouse’s income, and contributions to the household. What does matter is money spent on the affair. Joint funds used for gifts, travel, hotel rooms, or other expenses tied to the extramarital relationship can qualify as dissipation of marital assets, and a court that finds dissipation may adjust the property split to reimburse the innocent spouse.
Proving dissipation takes more than suspicion. The spouse making the claim generally has to show that specific marital funds were spent for non-marital purposes while the marriage was breaking down, usually through bank statements, credit card records, and receipts. Judges have wide discretion in how much weight to give the conduct.
Custody
Courts decide custody on the child’s best interests, and adultery alone almost never changes the outcome. A parent’s affair is generally treated as separate from parenting ability. The exception is when the conduct directly harms the child, such as exposing the child to inappropriate situations, neglecting parental responsibilities, or creating an unstable home. In those narrow cases, a judge may factor the affair into the custody arrangement.
Civil Lawsuits Against the Third Party
A small number of states still let a wronged spouse sue the person who had the affair. These are civil claims, not criminal charges, and the money at stake can be real.
Alienation of Affection
About seven states still allow alienation of affection suits. The plaintiff generally must show the marriage had genuine love and affection, that love was destroyed, and the defendant’s actions caused or contributed to the loss. The plaintiff does not have to prove the third party set out to wreck the marriage on purpose; the standard is whether the defendant intentionally acted in a way that would foreseeably damage the marriage. One jury verdict produced $2.2 million in compensatory damages and $6.6 million in punitive damages. Awards that large are outliers, but they show the exposure is not symbolic.
Criminal Conversation
Criminal conversation is a civil claim despite the name. It requires proof of only one thing: that the defendant had sexual intercourse with the plaintiff’s spouse. There is no need to show the marriage was loving beforehand or that the defendant caused any particular emotional harm. The act itself is the basis for liability. This tort exists in a smaller number of states and is often filed alongside an alienation of affection claim.
Military Penalties Under the UCMJ
The military treats adultery far more seriously than civilian law does. Under the Uniform Code of Military Justice, adultery is a chargeable offense when the government can prove three elements: the service member had sexual intercourse with someone, either the service member or their partner was married to someone else at the time, and the conduct was prejudicial to good order and discipline or brought discredit upon the armed forces.2United States Court of Appeals for the Armed Forces. United States Court of Appeals for the Armed Forces Digest – Article 134 Adultery That third element is what separates a private matter from a military offense, and commanders have broad latitude in deciding whether the line was crossed.
A service member convicted at court-martial for adultery faces potential forfeiture of all pay and allowances, confinement for up to one year, and a dishonorable discharge. A conviction at that level ends a career in every practical sense.
Not every case goes to court-martial. Commanders frequently handle adultery through non-judicial punishment under Article 15 of the UCMJ, which allows a commanding officer to impose discipline without a full trial.3Office of the Law Revision Counsel. 10 USC 815 – Art. 15. Commanding Officers Non-Judicial Punishment Article 15 consequences can include reduction in rank, forfeiture of pay, extra duty, and restriction to base. Below that level, a service member may receive a letter of reprimand or face administrative separation that results in a less-than-honorable discharge. Administrative actions carry less stigma than a court-martial conviction, but they can still end a career and affect veterans’ benefits.
Two details catch people off guard. The rules apply to a single service member who sleeps with someone else’s spouse, not just to the married service member; a single soldier who knowingly enters a relationship with a married person is equally subject to charges.4The United States Army. Legal Separation, Adultery, and the UCMJ And legal separation is not a safe harbor. A service member who starts a new sexual relationship while legally separated but not yet divorced still faces potential criminal liability or adverse administrative action.
Security Clearance Risk
For government employees and contractors who hold a security clearance, an affair creates a specific problem that has nothing to do with morality. The concern is blackmail. Adjudicators focus on whether undisclosed personal conduct could be used as leverage by a foreign intelligence service or another hostile actor, and an affair the clearance holder’s spouse does not know about is a textbook example of exploitable information.
The first question an investigator will ask after learning about an affair is who else knows. If the spouse is not on that list, the government treats the omission as confirming the blackmail risk. An affair will not automatically cost someone a clearance, but failing to disclose it when questioned, or allowing a situation where someone could use the information as coercion, sharply raises the odds of losing access to classified material. For officers and senior civilian officials whose positions depend on a clearance, that loss can be as career-ending as a UCMJ conviction.