Updated: Oct 15, 2020
Check your beneficiary designations on your insurance policies, your IRS Regulated Retirement Plans (IRA, 401k, etc.), and check your wills & trusts.
Insurance and IRS Regulated Retirement Plans pass to beneficiaries by CONTRACT, not by Will. Your beneficiary designation "trumps" your wills.
In this video, a Dad listed "Distribute assets according to my last will and testament" as a beneficiary designation. Since that is not a qualified beneficiary, the asset was distributed according to probate court - which gave the asset to his WIDOW (married for two months), rather than his children.
While with increasing computerization, this risk becomes far less and less common, but it is still important to verify. If you are not sure, contact your insurance company, plan providers, and/or estate attorneys to update everything to reflect your current wishes. If you have had a major change to your family situation: birth, death, divorce, marriage, etc., you should review your beneficiary designations to ensure that they reflect your current wishes.