Not completely, unless you and your spouse have waived the right to be included in the other’s estate in a prenuptial or postnuptial agreement. Each state has laws that shield a surviving spouse from being completely cut off.
In most states, the surviving spouse can choose between the property left in the deceased spouse’s Will or a statutory share set by state law (usually one-third or one-half of the estate). Whether it is advantageous to elect the state’s share – generous in some states, minor in others – depends on the rules for calculating the elective share, which rules and exceptions have a remarkable number of variations between the states.
In a community property state, the surviving spouse already owns half of the community property at the death of the other spouse.