@ivatan
I dropped out of the TurboTax "SuperUsers" group some years ago when they changed the program from SuperUsers to "Champions" whereby we were required to promote TurboTax via social media and sign NDA's, but I still get emails when posts are made to my old answers. In the main I never reply unless some "expert" - @RobertB4444 in this case - gives really bad advice.
Let's start with your 1099-R where you say "The 1099-R I received from my former employer shows the same amount in box 1 and box 2a." That strikes me as completely wrong so the first thing I'd do is go back to the employer and asks "what gives?" Based on your made-up numbers it seems like box 2a should be $12,000 such that $90,000 - $12,000 = $78,000. So the basis for ALL THE SHARES should be $12,000.
Next, the statement "long term sale occurs over a year after the purchase of the stock sold. In your case because it is less than a year between purchase and sale you will enter short term" just isn't the case. The whole point of taking stock with NUA is that the NUA is LONG TERM by definition, even if you sell the stock the same day you acquired it.
TurboTax just doesn't have any sort of "guidance" when it comes to this situation, so you need to sorta fake things a bit to get it entered properly.
