Get your taxes done using TurboTax
"1) ESPP: The "Adjusted Cost Basis" in ETrade Supplemental Form is different from "Cost Basis" in 1099-B. Should I correct those entries as well to the "Adjusted Cost Basis" in TT" and choose ""My 1099-B reports incorrect cost basis"?
2) RSU: The "Cost Basis" is 0 , so should I just correct it to Adjusted cost basis in TT?
As I said, ultimately you want to use the correct cost basis which should be the adjusted cost basis reported in the supplemental information provided by the broker. To keep life simply you could just change the basis reported on the 1099-B and be done with it. You wouldn't have followed IRS procedure - enter the basis on the 1099-B, then adjust it, and use a code to indicate why it was adjusted - but that's a "style" issue, not one of substance, and the IRS can't really lay a glove on you if your gain or loss is wrong. The only possible (remote) downside to this is that some computer would notice it an spit out a letter to you, that you'd have to respond to.
I don't use the MAC version but in the Windows version the easiest way to handle the trades correctly is to enter the 1099-B as it reads, click a button below the 1099-B entry form reading "I'll enter additional info on my own" then on the next page enter the correct basis in the "Corrected cost basis" box, and you are done.
The other way to do is is the enter the 1099-B exactly as it reads and then click a button below the 1099-B entry form reading "Guide me step by step." That's the path where you tell TurboTax about where you acquired the stock you sold and TurboTax gives you a customized interview for the stock. i think that's where TurboTax asks you if the amount reported on the 1099-B is correct.
It sounds to me like you might be clicking on that "Guide me Step by Step" button on the page where you enter the correct basis, (I'm assuming the MAC and Windows programs are the same here), and you don't want to do that!
Either use the 1st method of the 2nd method, but not both!
Since you have a desktop version I'm assuming that all the Forms, Schedules and Worksheets are always available to you, as they are in the Windows program. If so, simply open the Form 8949 where the trade(s) are reported and make sure you have them right. If they are not correct, go back to the interview, delete the trades and start over. Use either the "direct correction" of basis method (easiest and least error-prone) or use the step by step method.
(I've answered thousands of "stock" questions in here and have generally advised against using the step by step methods if you know what you're doing. The only exception I'll make to that generalization is if you have Disqualifying Dispositions of ESPP stock, then I'd suggest using the step by step method in that case.)
