Box 9a, percent of total distribution, is generally used when a 1099-R distribution is split between more
than one person. This is unusual, and if it was empty on the form you received you can leave it blank in TurboTax.
Option 1. You should leave box 9a blank in TurboTax if that section is blank/missing on your 1099-R. Click in the box and hit the backspace/delete buttons several times (or hold them down) to make sure the box is really empty.
Option 2. If you are unable to leave the space empty
(if you receive an error message), then you will need to delete and
manually re-enter the form. Here are the steps to do that:
https://ttlc.intuit.com/replies/4233654
