1099-R box 2a blank and 2b not checked

HI,

 

I recently received a 1099-R after I had already filed by taxes. Following are the details on this 1099-R :

 

  1. Box 1 has a gross distribution amount
  2. Box 2a has been left BLANK.
  3. Box 2b is NOT checked.
  4. There is an amount in box 5 that is about 10% less than the gross distribution amount in Box 1. 
  5. The distribution code in box 7 is BG.

    This was a  rollover from my previous employer's ROTH 401K to my current employer's  ROTH  401K account. Should I have reported this in my tax return? Was any portion of this distribution taxable?