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 Arizona, the law permits a no-fault divorce, which means that spouses can seek a divorce without needing to prove any wrongdoing or fault on the part of the other spouse. The primary ground for a no-fault divorce in Arizona is the assertion that the marriage is 'irretrievably broken' with no reasonable prospect of reconciliation. Arizona is a community property state, which typically means that marital assets are divided equally between the spouses upon divorce. However, while fault is not required to obtain a divorce, it may still be considered by the court in certain circumstances, such as when making determinations about spousal maintenance (alimony) or in matters concerning the welfare of children, including custody and support. It's important to note that while fault may influence these decisions, it does not change the fundamental approach to the division of community property in Arizona.