"Other contributions previously taxed by Massachusetts"
this is an interesting way to cook up a workaround in state of MA. But it is essentially a false statement.
"I'm not sure why this is necessary"
It's not necessary, when the entry is done correctly.
Your Traditional IRA contribution should be on Form 8606 Line 1 and that should take care of the issue you were seeing.
@bryonthego
@user17710097333
