IRA deductible contribution calculation while receiving Social Security Income

[Winstoncup]

Why is the taxable amount of my social security income different on the SS calc worksheet vs the IRA SS Worksheet?  Only a portion of my IRA contribution is showing as deductible on the IRA SS Worksheet because it is showing $3,000 more SS as taxable

[KathrynG3]

It depends. The taxability of social security is a complicated formula, but this link provides additional information: Is my social security taxable? 

Start with this calculation to determine what amount should be included in the IRA SS Worksheet.

[Winstoncup]

Thanks, I understand that a portion of the SS is taxable.  What I do not understand is why the 2 worksheets arrive at a different amount of the SS that is taxable.  The jSSBenefits Worksheet for 1040 Line 5 calculates the taxable amount at let's say 8000.  However, the SS Recipeints Who Contribute to a Traditional IRA Worksheet PAGE 1 calculates the taxable SS amount at 11,000.  That makes no sense to me as it results in a lower allowable IRA contribution which was not reflected nor calculated until I complete the State tax section.  Then, all of a sudden the calculation changed dramatically.  Since it did not recalculate until the 3rd time I had gone thru the taxes, it makes me suspect that it IS calculating correctly.  Also the SS Benefits Worksheet does not have any of the detail  on lines 2 thru 19 completed on said worksheet - just line 1 & 20.  I recalculated it using excel to confirm that figure.  Again, thank you for your assistance  🙂

[MaryK4]

There is a different calculation for the taxable social security for income tax and the new calculation for IRA contributions are different because they are used for different purposes.  

@Winstoncup