Although estate laws vary somewhat from state to state, they generally protect spouses from being completely disinherited or forgotten in a will. However, they do not normally address what might be fair in a divorce situation. There is a window of time during the breakup of a marriage when a soon-to-be ex-spouse can inherit everything you own if you pass away.
Uniform Probate Code
The Uniform Probate Code was enacted in 2005. Not all states adopted it, but if you live in one that did, it can affect how your estate is distributed if you die before your divorce is final. If you live in a state that adopted the UPC, have children and die without a will before the divorce is final, the UPC gives your entire estate to your intended ex-spouse -- including any premarital portion not normally received in a divorce. Even if you do leave a will and try to exclude your spouse before your divorce is final, the UPC will override your will and give her one-third of your entire estate, including premarital property that she probably would not have received in a divorce. If your spouse is a beneficiary under your will, you can’t change that until your divorce is final.
Extinguishment of Rights
Once your divorce is final, the laws in most states extinguish any rights your ex-spouse might have had to inherit from you, even if your will states that your ex-spouse gets everything, and you die before you can change it. Some states have statutes that will extinguish spouse's rights even during a legal separation. The only exception is if your will specifically states that it is your intention to supersede the law and leave your ex-spouse an inheritance anyway, regardless of a divorce.
One solution is to draft an interim will, according to the American Bar Association. Although most states will not allow you to disinherit a spouse completely and will award her an elective share up until the time you are actually divorced, an interim will can, at least, limit what your spouse receives from your estate to a share of only marital assets. Your will should mirror the terms of your divorce judgment or settlement, and it can exclude anything that would not be subject to equitable distribution in a divorce, such as premarital property or assets you yourself received by way of inheritance or gifts during the marriage. You are permitted to leave these to your children or other beneficiaries.
In most states, only the portions of your will dealing with your ex-spouse will be extinguished after a divorce. This means that if you do not draw up a new will, the court will have to decide what to do with the portion originally bequeathed you your ex. The court might decide to give that share to someone you would rather not receive it. Keep in mind that divorce extinguishes only your ex-spouse's rights under your will. Any insurance plans, retirement benefits or trusts that you might have in place with your ex as beneficiary would still pass to him on your death, even after the divorce is final.