Is social security income not taxable

Maybe. If Social Security is your only income it is not taxable.  If you have other sources of income either from working or other retirement accounts a part of your social security benefits could be taxable.  If you have other sources of income the easiest way to determine how much, if any, of your social security beneftis are taxable is to enter the information into TurboTax.  Once your income from all sources is entered in TurboTax, we will calculate the taxable portion of your benefits.  Entering this information does not mean you have to actually file the return.  You can just use the program to determine the correct tax treatment of your benefits.