Most states allow spouses seeking a divorce to allege fault in the breakup of the marriage as a basis for the divorce. Alleging the other spouse’s fault—rather than seeking the divorce on no-fault grounds (irreconcilable differences or incompatibility, making the marriage unsustainable)—is generally a basis for requesting the court make an uneven distribution of the marital or community property in favor of the spouse alleging the other’s spouse’s fault.

In states that allow a spouse to seek a divorce on fault grounds, the grounds that may be alleged vary from state to state, but generally include adultery, cruelty, conviction of a felony, family or domestic violence, abandonment, mental illness, and substance abuse (drugs and alcohol). Spouses may also seek a divorce on no-fault grounds in these states.

In no-fault states, a spouse is not allowed to allege fault as grounds for the divorce, and the court is not allowed to consider fault in dividing the marital or community property—but allegations of fault may be considered for other purposes, such as spousal support and child custody. No-fault states include California, Colorado, Florida, Hawaii, Indiana, Iowa, Kansas, Kentucky, Michigan, Minnesota, Missouri, Montana, Nebraska, Nevada, Oregon, Washington, and Wisconsin. And in some states “incurable insanity” is a no-fault ground for divorce.

The grounds on which a spouse may seek a divorce (fault or no-fault) are usually located in a state’s statutes—often in the family code or domestic relations code.

In New Jersey, spouses seeking a divorce have the option to file on either fault or no-fault grounds. No-fault divorce can be sought on the basis of irreconcilable differences, which does not require the spouses to live separately for any period before filing. Alternatively, spouses can file for a no-fault divorce after living separately for at least 18 consecutive months, indicating that there is no reasonable prospect of reconciliation. Fault grounds for divorce in New Jersey include adultery, desertion, extreme cruelty, separation, voluntarily induced addiction or habituation to any narcotic drug, institutionalization for mental illness, imprisonment, and deviant sexual conduct. While New Jersey allows for both fault and no-fault divorces, the choice of grounds can affect various aspects of the divorce proceedings, including the division of marital property, alimony, and child custody. However, the court will generally strive for an equitable distribution of marital assets, regardless of the grounds for divorce.