Marriage, divorce in the United States is the province of the state governments, not the federal government. Divorce or “dissolution of marriage” is a legal process in which a judge or other authority dissolves the bonds of matrimony existing between two persons, thus restoring them to the status of being single and permitting them to marry other individuals. The legal process for divorce may also involve issues of spousal support, child custody, child support, distribution of property and division of debt, though these matters are usually only ancillary or consequential to the dissolution of the marriage.

Divorce laws vary from state to state. Although all states allow “no fault” divorce proceedings, in many states a court may still take into account the behavior of the parties when dividing property, debts, evaluating custody, and support. No-fault divorce on grounds such as “irreconcilable differences” or a period of living apart is now available in all states, though some states require a legal and/or physical separation of up to two years prior to a formal divorce decree. This legal requirement, along with couples who live in a state of separation simply because neither has sought or completed a divorce for other reasons, has led to the creation of a separate, somewhat ambiguously-perceived category of relationships – “separated”.

Prior to the 1970s, divorcing spouses in many states had to allege that the other spouse was guilty of a crime or sin like abandonment or adultery; when spouses simply could not get along, spouses and their lawyers were usually able[citation needed] to negotiate “uncontested” divorces. The no-fault divorce revolution began in 1953 in Oklahoma; New York is currently the latest state to allow non-consensual no-fault divorce, in 2010. Every state’s law provides for child support where children are involved, and sometimes for alimony. The median length for a marriage in the US today is 11 years with 90% of all divorces being settled out of court.

In all but one state, and even in that state in most cases, a divorce must be certified by a court of law to become effective. The terms of the divorce are usually determined by the court, though they may take into account prenuptial or postnuptial agreements, or simply ratify terms that the spouses may have agreed to privately. In the absence of agreement, a contested divorce may be stressful to the spouses and lead to expensive litigation. Less adversarial approaches to divorce settlements include mediation and collaborative divorce, which negotiate mutually acceptable resolution to conflicts.

In cases involving children, governments have a pressing interest in ensuring that disputes between parents do not spill over into the family courts. All states now require parents to file a parenting plan, or to decide on custody and visitation either by reaching a written agreement or in a court hearing, when they legally separate or divorce.