how does Ttax figure tax on social security - interest and dividends?

[Didee]

This is my first year, 2024, getting social security.  I researched and it seems the calculations can be quite complex, yet TTax only takes info from my SS 1099...  How can it include the tax-exempt interest and dividends from my IRA accounts if I am not entering the info?

• Your brokerage doesn’t report it on a 1099-INT (since it’s inside a tax-deferred account).
•  The IRS only knows about tax-exempt income from an IRA because you, the taxpayer, report it when calculating your provisional income for Social Security taxability.

The IRS relies on your reporting on Form 1040, Line 2a, to figure out the total tax-exempt income that affects your Social Security tax calculation.

[Didee]

to add to the above -  Tax-exempt income from any source — taxable account or IRA — counts toward Social Security taxability because you are required to report it when calculating provisional income.

[SharonD007]

If you are single and made between $25,000 and $34,000 last year, up to 50% of your Social Security is taxable.  If you made more than $34,000, you'll pay taxes on up to 85% of your Social Security. When you enter all of your income, TurboTax will calculate the taxable portion of your Social Security.

Refer to the TurboTax articles Is my Social Security income taxable?, How does receiving Social Security affect my taxes? and When Does a Senior Citizen on Social Security Stop Filing Taxes?