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Intellectual Property Toolkit

What is the Public Domain?

Defined by the U.S. Copyright office a work of authorship is in the “public domain” if it is no longer under copyright protection or if it failed to meet the requirements for copyright protection. Works in the public domain may be used freely without the permission of the former copyright owner.

It is important not to confuse public availability with public domain. The availability of a document online has nothing to do with its copyright status. Even though there isn't a legal requirement to cite public domain works, you should still do so as a matter of best practice. Not citing your sources could be considered plagiarism which can have severe professional and educational consequences.

There are four common ways an item becomes available in the Public Domain:

As noted in 17 U.S. Code § 102 "In no case does copyright protection for an original work of authorship extend to any idea, procedure, process, system, method of operation, concept, principle, or discovery, regardless of the form in which it is described, explained, illustrated, or embodied in such work."
Not all federal government documents are in the public domain. Work by private individuals or contractors is frequently included in government documents through the use of a license. That work still has its own copyright.

  • The Copyright has expired.
    • All works made in the United States prior to 1923, publication date prior to 1923.
    • Works published in 1923 expired in 2019.
    • Works published in 1924 expired in 2020.
    • Works published after 1977, copyright will not expire until 70 years after the death of last surviving author.
  • The copyright owner failed to comply with copyright requirements at the them of publication or renewal.
    • Research with the Copyright office for works published between 1923 and 1964
    • Stanford University Libraries provide a helpful guide, Searching the Copyright Office and Library of Congress Records. 
  • Copyright never existed, such as facts, short phrases, ideas and select U.S. federal government documents.
  • Copyright owner places the item in the public domain.
    • A copyright owner may choose to release their work to the Public Domain.
    • This can be done with a Creative Commons CC0 license or
    • By placing a statement such as "This work is dedicated to the Public Domain" on their work.

Information for this section was based on information presented In "Public Domain" section of University of Pittsburgh Library System's Copyright and Intellectual Property Toolkit and "Welcome to the Public Domain" from the Stanford University Libraries.