TurboTax is reminding you that the effect of the return of the Roth IRA contribution was reportable on your 2016 tax return. The result on your 2016 tax return should have been that that amount returned was not included as part of your Roth IRA contribution, that any gains shown in box 2a of the Form 1099-R was included in income, if you were under age 59 when you received the return of contribution your tax return should have included Form 5329 calculating the 10% early-distribution penalty on the box 2a amount and that you included an explanation statement describing the return of contribution. If your 2016 tax return already showed these there is no need to amend your 2016 tax return.
