found this on the irs site (pub 551) which is what bsch4477 says:
In community property states (Arizona, California, Idaho, Louisiana, Nevada, New Mexico, Texas, Washington, and Wisconsin), married individuals are each usually considered to own half the community property. When either spouse dies, the total value of the community property, even the part belonging to the surviving spouse, generally becomes the basis of the entire property. For this rule to apply, at least half the value of the community property interest must be includable in the decedent's gross estate, whether or not the estate must file a return.
