Whether or not you may disinherit your spouse depends on the laws of the state in which you live. The laws vary considerably from state to state on this issue.
Many states have laws that protect a spouse from being disinherited.
The social policy behind these laws is that we don't want to create destitute, homeless widows and children without any means of support or a roof over their heads. In some states, it may be possible to totally disinherit a spouse through the use of a fully funded Revocable Living Trust or joint tenancy. A will cannot be used to disinherit a spouse because almost all laws that apply to spousal elections specifically apply to probate property. Many states have come to recognize prenuptial and postnuptial agreements that allow a spouse to waive or renounce his or her statutory rights in a deceased spouse's estate. These agreements are the most certain way to disinherit your spouse.