Families often assume an irrevocable trust means permanently locked, but a growing number of states now let a trustee rewrite the terms of an outdated trust without ever going to court. Professor Jack Ledger explains decanting, the practice of pouring an old trust's assets into a new one with better terms, and why the rules vary dramatically from state to state. He also flags the murkier federal tax questions the IRS has never fully resolved around the practice. It's a look at a little-known tool that can quietly modernize a trust frozen in an outdated version of the tax code.