You may not be able to totally

disinherit your hu*****and, if you are still married. If you need to dictate when your kids can start making withdrawals himself or herself, you need to create a living trust or a testamentary trust in your will. As for the estate tax, nobody can tell you cuz we don't know when you will pass away. If you pass away tomorrow, the first 5 million that does not go to your spouse is exempted. Also some states may levy state estate tax on you as well.