The Internal Revenue Service (IRS) publishes current and past tax forms on their website. The IRS also publishes many different instructional guides and publications to inform and instruct taxpayers.

Some states also collect income taxes. For information about finding state tax forms and publications, visit the Law Library's Guide to Law Online and consult the resources listed under the state that you are researching.

Forms for state income taxes are available online from that state's treasury department or revenue agency. For more information on how to locate online legal resources for a particular state, please see the Law Library of Congress's guides on its Guide to Law Online - U.S. States and Territories pages.