You didn't say, but I assume your father has died; I also assume that your father was completely incapacitated before he died. If he isn't incapacitated, ask him straight up whether he wants your brother to get all of his estate when he dies. If that's not your father's plan, then lawyer up and do it fast, or you will never ever be able to think of your father without thinking about how your brother ripped you off. And no, on just the issue of the taxes, if you got none of the money, there is no way you owe any of the tax.
Answered on May 18th, 2016 at 3:37 AM