It goes without saying that a qualified revocable trust becomes irrevocable when someone dies, and is therefore eligible to elect to be taxed as part of the estate and with a fiscal year.  But maybe @sjrcpa should have said it anyway. 

I feel sorry for these people who paid a paper mill for an estate plan with a bypass trust back when the estate tax exclusion was $600K, and didn't amend it when they had a chance.