Trusts required to file Form 990-T by the 15th day of the 4th month (April 15 for calendar year taxpayers) (including Employee plans, IRAs, SEPs, SIMPLEs, Coverdell ESA, and Archer MSA) should enter Return Code 05. Trusts required to file Form 990-T by the 15th day of the 5th month (May 15 for calendar year taxpayers) should enter Return Code 06.
