Amended 2019 for more income. Turbotax gives different amount

[Trooper2]

I had to add 20k to my return because I was careless and didn't get my husband's 1099-r.  I did the form through Turbotax  with my original return and the column B amount is about 7k more than the amount I added. What would make this happen? 

[VolvoGirl]

Adding more income would make more of any Social Security you get taxable.  

[NCperson]

@Trooper2 you can check the social security issue by reviewing the original return

Divide Box 5b by 5a.  if this is less than 85%, then adding the $20,000 to your income will add more to box 5b, so the result gets closer to or acheives 85%. I would expect that explains the entire $7,000. 

If Box 5b divided by 5a is already 85% before adding in the $20,000 then the problem is elsewhere. 

[rjs]

I assume you mean the column B amount on line 1. Compare the revised Form 1040 to the original 1040, lines 1 through 8a, to see which individual income items changed.

[Trooper2]

We are already at the maximum, but would that make the number in column B different, since it is referred to as the amount of increase?

[Trooper2]

Oops!  Nevermind!  It was the Social Security.  Thanks all, for putting up with me.