Bob Stoll, Commissioner for Patents

Bob Stoll, Commissioner for Patents

Q. If you use the USPTO Web site or Google Patents to do a preliminary search on patents, how can you confirm that the patent is actually an active patent? In other words, how do you know someone didn’t default by missing maintenance fees, etc.? Is there a way to determine if a listed patent is still valid?

A. There are a lot of things to consider when evaluating whether a patent is in force.

The first step is to make an initial estimate of the end of a patent’s statutory term based on its filing date.

For applications filed on or after June 8, 1995, the term of a utility patent begins on the date the patent issues. It ends 20 years from the date the application for the patent was filed.

Alternatively, if the application contains a specific reference to an earlier filed application or applications under 35 U.S.C. 120, 121, or 365(c), the patent expires 20 years from the filing date of the earliest of such application(s).

So, utility patents have a 20-year term. Design patents have a term of 14 years from the date of patent grant.

Once you’ve determined an initial estimate of the end of a patent’s term, you have to look to other factors, which may either shorten or lengthen the patent term.

While not an exhaustive list, factors affecting the length of a patent’s term include failure to pay patent maintenance fees, a terminal disclaimer, patent term adjustment (PTA), patent term extension (PTE), reexamination, and certain findings in litigation.

The USPTO offers a quick and easily accessible online tool for checking to see if a patent owner (or patent assignee) is up to date with all patent maintenance fee payments for a specific patent.

Using the search query on the USPTO’s site called “expired patents,” you find a Web page that allows a user to enter a patent application number and patent number to determine the patent’s status.

The public also can look at the content of a patent’s electronic file record to see activity in the patent file after the patent has issued. This can be done using the USPTO’s Patent Application and Information Retrieval (PAIR) tool.

Furthermore, the USPTO publishes its weekly Official Gazette, which provides a listing of expired patents as of a certain date due to the failure to pay patent maintenance fees.

Commercial Web sites also exist that provide full or partial listings of expired patents.  On word of caution with respect to patents that have expired due to a failure to pay patent maintenance fees: In certain instances these patents may be reinstated if a patent owner meets established requirements.

Editor’s note: this article appears in the February 2010 print edition.