New York State law under DRL, Section 236(B)(3) provides for the parties to make an agreement before or during the marriage that may include provisions for the ownership division and distribution of separate or marital property.
A written agreement may be a prenuptial or postnuptial agreement that you and your spouse entered into at the time of marriage or at any time afterward.
These agreements can specify that certain property should or should not be considered marital or separate property in the event of a divorce or separation.