Cal. Prob. Code § 11440

If it appears that a debt of the decedent has been paid or is payable in whole or in part by the surviving spouse, or that a debt of the surviving spouse has been paid or is payable in whole or in part from property in the decedent’s estate, the personal representative, the surviving spouse, or a beneficiary may, at any time before an order for final distribution is made, petition for an order to allocate the debt.