Property that is owned in joint tenancy with right of survivorship does not pass under a will. If a will gives property to one person but it is already in a joint account with another person, the will is usually ignored and the joint owner of the account gets the property. The property in the account avoids probate and passes directly to the joint owner. A will only controls property that goes through probate.
Putting property into joint tenancy does not give absolute rights to it. If the estate owes estate taxes, the recipient of joint tenancy property may have to contribute to the tax payment. Also, some states give spouses a right to property that is in joint accounts with other people.
Example 1: Ted and his wife want all of their property to go to the surviving spouse. They put their house, cars, bank accounts and brokerage accounts in joint ownership. When Ted dies, his wife only has to show his death certificate to get all the property transferred to her name. No probate or will is necessary.
Example 2: After Ted's death, his wife, Michelle, puts all of the property and accounts into joint ownership with her son, Mark. Upon her death, Mark needs only to present her death certificate to have everything transferred into his name. No probate or will is necessary.
Tenancy by the Entireties
In some states, there is a form of joint ownership just for married couples called tenancy by the entireties. It offers some extra protection from creditors. If you are married and are seeking to hold property by tenancy by the entireties, you should use the precise language, "spouses in a tenancy by the entireties" after your names.
Example: Lindsay and her husband Rocky bought a house. When Rocky suddenly died, Lindsay obtained full ownership of the house by filing a death certificate at the courthouse. The deed to the house stated that they owned the house as husband and wife in a tenancy by the entireties.