Some of the forms can be filled in on your computer using Adobe Acrobat Reader. For those forms, and mail it to the appropriate address. If you need to file a tax return for a previous tax year, complete, print, and mail the tax form(s) to the IRS. The correct IRS mailing address is printed on each of the tax forms. But you can download, save the form on your computer when finished, print it, you cannot efile that tax return. The current revision date is shown with each form listing. Revision dates are shown either by the tax year or by the month and year they are revised.