The 1099-R is from OPM, as I'm a Postal Service retiree.
"Learn more" says, "If you have basis - an amount of money you contributed and already paid taxes on - in your retirement funds, then you'll use one of two methods (Simplified method or General Rule) to determine the taxable amount..."
How/when could there be a situation where I contributed money to OPM and already paid taxes on it? Or how would I know if I did?
Note: I also clicked the links to "simplified method" and "general rule" but that info just raises *more* questions. I don't remember getting stuck here last year.
Oh here's another possible clue: Both this year and last year, the amount in box 2a of my 1099-R form was precisely $401.76 less than the box 1 "gross distribution" even though the gross distribution and taxable amounts between the two years are quite different. That seems incredibly coincidental and unlikely. I have no idea where the $401.76 came from.
And finally, from "Learn more" it says "Take a look at your 1099-R from last year.... Generally, the taxable amount would be on line 16b of your 2020 1040." But there's no line 16b on last year's 1040. Moreover, line 16 is labeled "Tax," not "Taxable amount." I'm wondering if the mention of line 16b was a mistake by TurboTax.
