When Do US Patents Expire

written on April 15, 2009 by David Burge

I am often asked about the expiration dates of patents.  The answer used to be much simpler, namely 14 years after issuance for Design Patents, and 17 years after issuance for Utility Patents.  These days, however, the answer is far more complex, as the following explanation illustrates.

In the United States, Design Patents (which protect ornamental features of articles of manufacture) have shorter terms than Utility Patents (which protect inventions relating to such things as how devices are built and how they function).  When most folks use the term "patent," they are referring to a Utility Patent, not to a Design Patent which provides different protection than a Utility Patent.

All of the Design Patents that still are active (i.e., "in force") in the United States will expire 14 years measured from the dates on which they issued as patents from the U.S. Patent and Trademark Office (the USPTO).  Some older Design Patents had term lengths that were elected by paying USPTO Issue Fees that cost more if the patent owner elected a longer term of up to 14 years instead of a shorter term.

Not all U.S. Utility Patents have terms of the same length.  Those Utility Patents that expired prior to June 8, 1995 had 17-year terms measured from the dates on which they issued as patents from the USPTO.  A term of 20 years from the earliest applicable application filing date now applies to Utility Patents issuing from applications that were filed in the USPTO on or after June 8, 1995.  Many Utility Patents having patent numbers between 5,400,000 and 5,900,000 fall into this category.

U.S. Utility Patents that were still in force on June 7, 1995, and U.S. Utility Patents that issued on or after June 8, 1995 from applications filed before June 8, 1995 have terms that are the longer of two possibilities:  1) 17 years measured from their issue dates, or 2) 20 years measured from the earliest applicable application filing date.  This "longer of two possibilities" option applies to many U.S. Utility Patents that bear patent numbers between 4,094,014 and 5,900,000. 

Most U.S. Utility Patents that remain active today expire 20 years measured from the earliest filing date of an associated Utility Patent application.  However, if the owner of a Utility Patent fails to pay any of three Maintenance Fees that are due 3.5, 7.5 and 11.5 years following the issue date of the Utility Patent, the Patent lapses unless the unpaid Maintenance Fee is paid during a six-month grace period together with a Late Payment Surcharge Fee.

Maintenance Fees apply to all U.S. Utility Patents issuing from applications filed on or after December 12, 1980 -- which means that Maintenance Fees apply to all Utility Patents that currently are in force (i.e., those that have not expired).  If the payment of a Maintenance Fee was unintentionally overlooked, it may be possible to revive the patent that lapsed as a result; but consult your pa­tent attorney in the event that patent revival is needed, and act diligently to attend to the overlooked fee payment upon discovery of a failure to timely pay a Maintenance Fee, for revival can be tricky, and acting promptly and with diligence may affect the result.

Some U.S. Utility Patents issued from original applications filed between June 8, 1995 and May 28, 2000, and all U.S. Utility Patents that issue from original applications filed on or after May 29, 2000 may be eligible to have their terms extended by a few days to compensate for such things as prosecution delays that occurred through no fault of the applicant during application pendency.  Some of these term extensions are stated on the front pages of the patents to which they apply; and most are made "of record" in the file histories of the patents to which they apply.