The contracts made by a married person with respect to the person's individual property, labor, or services are not binding upon the person's spouse and do not render the spouse or the spouse's property liable for the contracts. However, the contracting person and that person's individual property are liable on the contracts in the same manner as if the person were single.
Liability Of Spouse
Mont. Code Ann. § 40-2-302, under Power of Married Persons to Contract.
Mont. Code Ann. § 40-2-302