LOOK AT whether the IRA box in line 7 is checked (I am talking about the box, not the line 7 code). IF it is checked then TurboTax will deduct whatever nondeductible IRA contributions you have been recording on Form 8606 from your taxable income (it seems to deduct them in full from the 1st distribution). If you have made non deductible contributions to that IRA and have not created form 8606 for those then then I guess you will need to create form 8606.
I am not a tax professional, but the above is what happened on my 1099-R for my 1st RMD
