When I have 1099Rs on a 1041, I just list the taxable amount under Other Income on the front of the 1041.  I 'think' that funnels it to the Other Portfolio Income line of the K-1 (I dont have one in front of me right now)

Same 1099-R with 10% taxes withheld, "taxable" amount and taxes should stay in trust and not paid out to beneficiary. Where are these amounts entered to require that trust pays the tax?