To order federal 2016 tax products delivered by mail from the IRS go to:
Forms and Publications by U.S. Mail
If you type in one of the form numbers you need (Eg. 1040) in the Search box and hit Enter, a list of forms and instructions you may order will appear. Click the boxes next to the ones that you want and then click on the Add to Cart button. Continue until you have added all of the forms and instructions that you need. (If you are brought to your Shopping Cart before you are finished, just click on the Resume button to return to the list.) If you need a form NOT on the list, use the Search box at the top to find it.