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. While fault is not required to obtain a divorce, allegations of a spouse's misconduct may still be relevant in certain aspects of the divorce proceedings, such as determining spousal maintenance (alimony) or in matters concerning child custody. However, when it comes to the division of marital property, Arizona is a community property state, which typically means that marital assets and debts are divided equally, regardless of fault. It's important to note that while fault may not play a direct role in the division of property, egregious financial misconduct by one spouse, such as the wasteful dissipation of assets, could potentially influence the court's decision on property division.