Multi-Step U.S. Patent Search Strategy

Summary of the Multi-Step U.S. Patent Search Strategy

  1. Brainstorm terms describing your invention. Try to think of alternative words to describe your concept. For example, an umbrella could also be called a parasol or a sunshade.
  2. Conduct a keyword search using Patent Public Search. You can begin with a broad search for your main concept, and then narrow the search results by adding additional features of your invention. Review the front pages of patents and published patent applications, eliminating those that are irrelevant. Guidance on how to search is available in our Quick Reference Guides.
  3. Conduct an in-depth review of the documents found by your search. Review in detail the complete patents and published patent applications you found that are similar to your invention. Don’t forget to review the drawings, specification and claims for similarities to your invention.
  4. Expand the search with relevant CPC classifications. Go to the Classification Resources page and select the CPC classification system. Find a relevant classification and use it in a classification search in Patent Public Search’s Advanced Search with the .CPC. field code.
  5. Review cited references. The front page of a patent includes a section of cited references provided by the applicant and/or the patent examiner. Review the U.S. patents and published patent applications that a patent has cited and/or the patents that have cited them since their publication. Patent Public Search can provide a search of both the backward and forward citations.
  6. Broaden your search with foreign patents, non-patent literature and/or a patent professional’s search. Check Espacenet, the European Patent Office’s worldwide patent publication database of over 140 million patent publications. Also search books, journals, websites, technical catalogs, and conference proceedings in the applicable field. You may want to hire a registered patent attorney or patent agent to review the search.

Search preparation and documentation

Plan on spending hours learning the search process, searching, and evaluating results. The length of time spent on your search depends on the complexity of the invention. It is important to carefully record the details of your search process, such as the databases you used, the date and time of your search, the keywords you searched, and which patents/published patent applications were retrieved.


Additional Resources 

The Patent and Trademark Resource Center Program also provides a CBT (computer-based training) tutorial with a detailed review of the step-by-step strategy. The current CBT covers searching using Cooperative Patent Classification (CPC).

Search assistance at a Patent and Trademark Resource Center (PTRC)

PTRC library staff around the country are available to provide training on U.S. patent search processes and research tools including Patent Public Search. For the PTRC nearest you, check