Under the law of some community property states, married persons may agree to convert some or all of their separate property to community property. Such an agreement may be referred to as an agreement to convert separate property to community property or as a transmutation agreement.

The legal character or nature of debts of married persons may also be changed by transmutation in some community property states—changing debts of the parties’ separate estates to debts of the community estate, or debts of the community estate to debts of the separate estates. But an agreement between married persons to change a community debt to the debt of one of the spouses separate estates may not be binding on the creditor—unless the creditor agrees in writing to only look to one spouse for satisfaction of the debt.

In community property states, the laws regarding the availability and scope of transmutation agreements vary from state to state. These laws are usually located in a state’s statutes—often in the family code or domestic relations code.

In Idaho, which is a community property state, married couples have the option to change the legal status of their property from separate to community through a transmutation or conversion agreement. This process allows spouses to mutually agree to treat specific separate property as community property, which would then be subject to division upon divorce or death of one spouse. Similarly, debts can also be transmuted, changing the responsibility from being separate to community or vice versa. However, it's important to note that such an agreement to change the nature of a debt may not be enforceable against a creditor unless the creditor consents in writing to pursue only one spouse for repayment. The specifics of these agreements and their enforceability are governed by Idaho's statutes, which can be found in the sections pertaining to family law or domestic relations. Couples considering transmutation agreements in Idaho should consult with an attorney to ensure that their rights and intentions are properly documented and legally enforceable.