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 Mexico (NM), spouses seeking a divorce have the option to file on either fault or no-fault grounds. No-fault divorce is based on incompatibility, which means that the spouses agree that their marriage cannot be sustained due to irreconcilable differences. On the other hand, New Mexico also allows for fault-based divorces, where one spouse can allege specific grounds for the divorce such as adultery, abandonment, cruel and inhuman treatment, and others. While New Mexico is not strictly a no-fault state, the court typically does not consider fault when dividing marital property unless the behavior is so egregious that it clearly wasted marital assets or affected the economic circumstances of the parties. However, fault may be considered in other aspects of the divorce proceedings, such as determining spousal support or child custody. The specific statutes governing divorce in New Mexico can be found in the state's statutes under the family law or domestic relations sections.