有可能不對，僅供參考：在加州，夫妻最好用Community Property with Rights of Survivorship來hold 房產title。如不用再refinance 了，可用 Family Living Trust 來hold Title。另外Portability不是自動的吧，需及時給IRS File the right form. Joint Tenancy tax base 是要 step up的。From Google:
If spouses held property as joint tenants or as tenants by the entirety, the surviving spouse's total basis in the property is deemed to be one-half of the original cost basis and one-half of the fair market value of property on the date of the decedent's death (or alternate valuation date)...
