We cannot make changes to Box 2a of the 1099-R. It is the customer’s responsibility to determine the appropriate taxable portion when filing their tax return by completing the Form 8606. The taxable amount in Box 2a on the 1099-R is frequently incorrect for Traditional IRA and Roth IRA distributions. This can happen at many investment firms. Read below to see why this is the case, and how you can correct it when filing your taxes. The taxable portion of a Traditional or Roth IRA distribution is ...