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 South Carolina, marital property is not recognized as community property, as South Carolina is an equitable distribution state rather than a community property state. This means that during a divorce, marital property is divided equitably, but not necessarily equally, between the spouses. A marital property partition agreement, known in South Carolina as a postnuptial agreement, is a legal document that spouses can enter into during marriage to designate certain marital property as the separate property of one spouse. These agreements must be in writing, signed by both parties, and notarized to be enforceable. The agreement allows spouses to determine how their property should be divided in the event of a divorce or death, rather than leaving the decision solely to the courts. It is important to note that such agreements are subject to certain legal requirements and must be entered into voluntarily, with full financial disclosure, and without duress or undue influence to be considered valid. If spouses cannot agree on the division of property, the courts will intervene and divide the property in an equitable manner, considering various factors such as the duration of the marriage, contributions to marital property, and the economic circumstances of each spouse.