Something labeled “defective” usually does not work properly. The intentionally “defective” grantor trust, or “IDGT,” however, is a proven workhorse for tax-efficient business succession planning. A carefully planned and executed IDGT transaction enables business owners to transfer significant value in trust for the benefit of younger generations, with remarkable tax efficiency, while retaining control over the business. Two seemingly contradictory tax attributes of the IDGT underlie its tax efficiency.