How can I determine why TurboTax is not calculating taxable social security income properly (using factor of 40% instead of 15%)?

[VolvoGirl]

Do you get Social Security Benefits on a SSA-1099?

Up to 85% of Social Security becomes taxable when all your other income plus 1/2 your social security, reaches:

Married Filing Jointly: $32,000

Single or head of household: $25,000

Married Filing Separately: 0

Social Security is on 1040 line 5a and the taxable amount on 5b.

To see the Social Security Benefits Calculation Worksheet  in Turbo Tax Online version you would have to save your return with all the worksheets to your computer.  Or if you are using the Desktop program you can switch to Forms Mode (click Forms in the upper right) and click on SS in the list on the left side.

[DoninGA]

TurboTax uses the same worksheet as the IRS Social Security Benefits Worksheet to calculate the taxable amount of Social Security benefits.

IRS Form 1040 Instructions Social Security Benefits Worksheet on page 28 - https://www.irs.gov/pub/irs-pdf/i1040gi.pdf#page=28

[VolvoGirl]

Why do you think it should be 15%?  Are you asking about the 15.3% self employment tax on your self employment income?

[Bben99]

What about the exceptions, IRS says go to 590 appendix B, turbo deluxe has totally different form and result= higher taxable.

[JohnB5677]

590 Appendix B is the life expectancy table used to calculate RMD's.

The calculation of your taxable Social Security can be found in the Online version after you've paid or in the Forms mode in the Desktop version.  It is listed as the Social Security Benefit Worksheet (It may be abbreviated in TurboTax).

This link gives the instructions and examples of the calculation worksheet.  

IRS Social Security Worksheet

[Bben99]

I'm looking at 1040 instructions, refers to 590A, appendix B. This worksheet does not match the Deluxe social security worksheet, sequence or results.

[DaveF1006]

Without being able to look in your return, it is hard to determine what the issue is if any. At this point you may wish to contact a specialist that can work through that section of the return with you. The specialists can look at your return on their screen to be able to determine if Turbo Tax is calculating the correct amount of Taxable Social Security benefits.

[azJim]

In 2020 Turbo Tax stopped calculating the taxable SSI on the what-if worksheets.  Is that an error or a planned revision?  Thanks,

[DaveF1006]

it depends. To my knowledge, SSI benefits are not taxable according to irs.gov. Are you referring to regular social security payments?