Do beneficiary designations and joint ownership override my will?

Yes, and understanding this hierarchy prevents major mistakes. Assets that pass by beneficiary designation, such as retirement accounts and life insurance, and assets held in joint tenancy with right of survivorship or with transfer-on-death registrations, bypass your will entirely and go directly to the named person or co-owner. Your will only controls assets that don't have another mechanism attached, plus anything routed through it. So if your will leaves 'everything equally to my three children' but your 401(k) names only one child, that child keeps the whole account regardless of the will. Coordinate all your beneficiary designations, account titling, and your will so they tell one consistent story. A periodic audit of how each asset will actually transfer is one of the highest-value estate reviews you can do.