Where are you seeing the full amount of the SS benefits being taxed?
The total of the SS benefits received is on the Form 1040 Line 6a. The taxable amount of the SS benefits is on Line 6b and it will never be more than the amount of 85% of Line 6a.
Click on Tax Tools on the left side of the screen. Click on Tools. Click on View Tax Summary. Click on Preview my 1040 on the left side of the screen.
