The TurboTax software uses the IRS worksheet for determining if the SS benefits reported are taxable. SS benefits reported on Form 1040 Line 5a and the taxable portion of the benefits reported on Line 5b.
IRS worksheet from IRS Publication 915 Social
Security
and
Equivalent
Railroad
Retirement
Benefits on page 16 - https://www.irs.gov/pub/irs-pdf/p915.pdf#page=16
Up to 85% of Social Security Retirement/Disability/Survivors benefits 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