From Page 4 of Instructions for Form 1041:
Distributable net income (DNI). The income distribution deduction allowable to estates and trusts for amounts paid, credited, or required to be distributed to beneficiaries is limited to DNI. This amount, which is figured on Schedule B, line 7, is also used to determine how much of an amount paid, credited, or required to be distributed to a beneficiary will be includible in his or her gross income.
Please refer to the following link for additional information:
IRS Instructions for Form 1041
You can distribute corpus, but it generally is not taxable because only the taxable income is reported on the 1041. The taxable income is allocated to beneficiaries via k-1 and any excess distributions (corpus) beyond the taxable income does not show on the 1041 nor k-1s unless a comment is made in the comment section to that effect.
Also, the amount of corpus distributed beyond the taxable income allocation is also not deductible on the
