Legal Question in Family Law in California

Without reviewing the exact details of how the funds have been handled, it is not possible to say for sure how this would be treated. Generally, however, the circumstances you describe would not be considered comingling. If the two trusts shared a single bank account, for example, that would be classic comingling. In this situation there is just a one-way flow of money from the separate property trust to the community and a community trust. Separate property spent on community expenses is generally treated as a gift to the community, absent clear proof of a contrary intent. Separate property contribution to acquisition or enhancement of an asset, however, brings into play the Moore-Marsden rule. In the situation you describe, the rule would be applied to the mortgage payments. The portion of the payments that has gone to pay interest, and any impound or escrow accounts set up by the lender for expenses would be a gift to the community. The portion of each payment that went to pay down the principal, however, increased the community equity in the property. The Moore-Marsden calculation establishes a reimbursement that the community owes the spouse whose separate property contributed to the increase in equity.