@turbler wrote:
To quote the IRS instructions, this is a 1041 filed by a trust "as if it were an estate."
There is always an estate, as it is simply the net worth of a decedent (which can even be negative), and the instructions (as well as Section 645 and the Regs) provide for a qualifying trust to be treated as part of the estate, not "as if it were an estate".
The 1041 needs to be filed in accordance with the foregoing which is as an estate with a qualifying trust.
