Under current United States law, the term of a utility patent is 20 years from the filing date of the earliest U.S. or international (PCT) application from which priority is claimed. This presumes, of course, that applicable maintenance fees are timely paid to the Patent Office (at four, eight and twelve year anniversary dates from when the patent first issued).
It used to be that the term of a patent was 17 years from the date the patent was issued; this changed back in the mid-1990’s as part of the updating of the U.S. patent laws. This updating was done so that the U.S. patent laws would be consistent with the World Trade Organization’s Agreement on Trade-Related Aspects of Intellectual Property Rights (TRIPs).
By comparison, U.S. design patents have a shorter term than utility patents. Design patents filed on or after May 13, 2015 have a term of 15 years from issuance. Design patents filed prior to May 13, 2015 have a term of 14 years from issuance.
If the United States Patent Office fails to examine a patent application in a timely fashion (deadlines for various steps during the examination process are different), the patent term may be extended. On the other hand, extensions or other delays taken or caused by the patent applicant during application examination can reduce or eliminate whatever patent term extension might be available.
The extension of the patent term is typically referred to as a patent term adjustment (PTA). The purpose of it is to take into account delays caused by the U.S. Patent Office during examination of a patent application. The total PTA that may be given to an issued patent is an addition to the 20-year patent term. Such delays include when the Patent Office fails to timely reply to a filed application or to a patent applicant’s response to an Office Action as well as when the overall examination of the patent application exceeds three years.
In contrast to extending the term of a patent, the patent term can also be reduced. This most often occurs when the patent applicant is required to file what is referred to as a terminal disclaimer. A terminal disclaimer is a process by which a U.S. patent’s term is shortened because its coverage overlaps with the coverage of another patent owned by the same patent applicant and which expires sooner. If this is the case, the patent applicant may be required by the Patent Office to give up a part of the 20-year patent term.
Most of the information for determining the term of a patent can be found on the front page of an issued patent, including its issue date, its filing date (or the filing date of the U.S. or PCT application from which priority is claimed), the PTA that was granted and if a terminal disclaimer was filed.