Most of the times, a party would own a certain property (typically, a house) and upon marriage, continue to own it and pay the liabilities (mortgage payment, taxes and insurance, etc.) subsequent to the marriage. The property is also refinanced several times and the spouse's name is not added (because of bad credit, insufficient income, etc.).

The question becomes whether, after all the long years of marriage, whether the property is community property or separate property.

The law is very clear. If the down-payment came from the owner-spouse's separate property, he or she may have a reimbursement claim under Family Code Section 2640.

The right to reimbursement claim extends to include down payments, payments for improvements, and payments that reduce the principal of a loan used to finance the purchase or improvement of the property but do not include payments of interest on the loan or payments made for maintenance, insurance, or taxation of the property.

Both the spouses nonetheless are likely to have equal community property interests in the equity/appreciation in value of the house since the time of the marriage.

If one spouse's name is not on the title during the refinance because of whatever reasons (bad credit, a spouse not working or insufficient income), one may argue that the Civil Code presumptions of title do not apply because changes in title did not affect the characterization of the property. This is a complex area of the law that most certainly requires representation by an experienced Family Law Attorney.