Why does the program insist I enter a letter in box 7 on my 1099-R

[nauvooandstar]

My 1099 only shows a 7 in box 7, no letter. Turbotax keeps adding a D.

[SamS1]

The D indicates the distribution is from an annuity or life insurance payments.  If you selected in TurboTax the payments were from a non-qualified plan, it is indicating that with the D lettering in box 7.  This does not effect the taxability of the the distribution.