Deductions & credits

Thanks for the clear and simple explanation, RobertG. Now I get the concept!   I  followed the links and did a bunch of reading and remain mystified how I type this info into the Form 8958. I did the math, added the income for my spouse and myself. Divided in half, and figured out which amount gets added or subtracted so we each report 50% of our total income.   When I entered the allocation in column B, however, turbo tax decided to change the amount previously auto-filled in Column A.  It would be so helpful to simple see an example of how it is done. I am not finding the TT software helps with this calculation.  It didn't offer the step-by-step on mine either.