Can i just go by AGI from last year if i am filing single this year?

[bluedeb · Accepted solution]

If you are referring to e-filing your return, you do use your 2017 AGI.  It does not matter what your filing status is for 2018. Your 2017 AGI is

• On your originally-filed 2017 tax return, form 1040 (Line 37), 1040A (Line 21), 1040EZ (Line 4), 1040NR (Line 36), Form 1040X (Line 1, column A)

[boogley2010]

does it have to be the total of both incomes from you and your spouse?

[bluedeb · Accepted solution]

Your AGI is not your income from your W-2's.  If you filed a joint return in 2017 then you would use the whole AGI number from the joint return.  Do not split it.  To find your 2017 AGI look at the above answer for what line to look at.