If you are e-filing and have entered Forms 1099-R that have an amount in box 4, TurboTax automatically includes in your e-filing the details that you entered from the Form 1099-R provided by the payer. This electronically "attaches" the Form 1099-R to your e-filed tax return so that you do not need to provide the IRS with the printed Copy B.
If you are filing by mailing a printed federal tax return, you must attach Copy B that you received from the payer.
