MA state tax for non-resident with tax treaty

[anojjj]

I am an international student on F1, a resident alien for federal tax filing and a non-resident for MA state tax filing. I had a remote appointment last year and worked x days outside the US and y days physically in MA.

My home country also has a $5000 tax treaty exemption with the US and my school in MA has already considered this treaty so the amount in my W2 box1 is my salary (let's denote it by s) - 5000, the post-treaty amount.

1. So I need to apportion my W2 income based on the working days in MA and outside MA right?

2. So should the MA taxable income be (s-5000)/(x+y)*x or s/(x+y)*x-5000? Bascially, should I use the post-treaty salary for apportion or the pre-treaty salary to apportion and then deduct the exemption?

Thanks!

[ErnieS0]

If I understand your question correctly, both your W-2 box 1 (federal wages) and Box 16 (state wages) already include a $5,000 subtraction.

Massachusetts starts with federal income. If both boxes include the adjustment you should not add any wages to either your federal or state total. 

[anojjj]

Yes, both boxes already include a $5,000 subtraction. In that sense, I should use the box 1 number to apportion based on working days? w2-box1-amount/(x+y)*x? Thanks!

[DaveF1006]

Yes, that is correct to use the amount reported in Box 1.

@anojjj