TurboTax does a terrible job with QCD, Qualified Charitable Distributions. It’s almost impossible to figure out how the data in box 2a of Form 1099-R should be entered.

You will enter your Form 1099-R exactly as shown on the Form (enter the amount from box 2a into field 2a in TurboTax). Please follow these steps to enter your Qualified Charitable Distributions (QCD):

1. Login to your TurboTax Account 
2. Click on the "Search" on the top and type “1099-R” 
3. Click on “Jump to 1099-R” and enter all your information as shown on your Form 1099-R (make sure the IRA box is checked) on the "Enter your 1099-R details" screen
4. Continue until "Tell us if any of these uncommon situations apply" screen and check "I transferred all or part of this money directly to charity"
5. Continue through the questions

Please be aware, you must be age 70-1/2 or older at the time the distribution is made to QCD. 

I do not know whether or not this works.   It came too late.   I had already figured out a sloppy method to get around the program's limitations, and I had by then submitted my tax form to the IRS.

It works, and you will probably get an IRS notice near the end of the year for your manual adjustment of the form since it won't have properly reported this as a QCD on your return.  Make sure your records of theQCD are easy to find so you can reply to that notice.  Or amend the return when you can - your way won't report it properly and the IRS does notice.