A marital property partition agreement—also known as a partition and exchange agreement, a postmarital agreement, or a postnuptial agreement—is an agreement between spouses during marriage to convert marital property (also known as community property in some states) to one spouse’s separate property.

Property that is jointly owned by spouses or domestic partners (often owned as joint tenants with a right of survivorship) may also be partitioned or divided in a lawsuit or court action rather than by agreement of the spouses.

Laws regarding marital property partition agreements vary from state to state and are generally located in a state’s statutes—often in the family code or domestic relations code.

In Arizona, which is a community property state, a marital property partition agreement, also known as a postnuptial agreement, allows married spouses to alter the legal status of their property. Under Arizona law, property acquired during the marriage is generally considered community property, meaning both spouses have an equal interest. However, a partition agreement can be used to convert community property into separate property, which would be owned by only one spouse. This type of agreement must be in writing and signed by both parties to be enforceable. It is important that the agreement is entered into voluntarily and with full disclosure of all assets. If spouses cannot agree on the division of property, they may seek a court action to partition the property. The relevant statutes can be found in the Arizona Revised Statutes, particularly within the sections pertaining to marital and domestic relations. It is advisable for spouses considering a partition agreement to consult with an attorney to ensure that the agreement complies with Arizona law and to fully understand the legal and financial implications.