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 Missouri, a spouse can seek a divorce on both fault and no-fault grounds. The no-fault ground in Missouri is the irretrievable breakdown of the marriage with no reasonable likelihood that the marriage can be preserved. When it comes to fault grounds, Missouri recognizes several, including adultery, abandonment for at least six months, living separate and apart by mutual consent for at least 12 months, living separate and apart for at least 24 months without mutual consent, incompatibility due to mental illness or incapacity, and others. While Missouri is a no-fault state and does not require spouses to prove fault to obtain a divorce, fault can still be a factor in the proceedings. For instance, a judge may consider fault when making decisions about spousal support (alimony) and the division of marital property, although the primary basis for property division is equitable distribution. Additionally, fault may be relevant in determinations regarding child custody and visitation rights.