A residuary trust, also known as a B-trust, is the second part of a two trust arrangement that is created for the benefit of the trustor's spouse, states InvesterWords. This trust fund is not considered part of there estate, and is therefore not taxable to the trustor or the surviving spouse.
A residuary trust is typically the property of the decedent's equal to the remaining exclusion amount, as noted on the Business Dictionary website. It is part B of the A-B trust, otherwise referred to as the marital residuary trust. The A-trust is all of the decedent's assets that in excess of the allowed exclusions. This is designed as a catch-all to any assets not specifically gifted in the trust, states Dennis Fordham, an tax attorney writing for Lake County News.