All utility patents which issue from applications filed on and after
December 12, 1980 are subject to the payment of maintenance fees which
must be paid to maintain the patent in force. These fees are due at 3½,
7½ and 11½ years from the date the patent is granted and can be paid
without a surcharge during the “window-period” which is the six month
period preceding each due date, e.g., 3 years to 3 years and six months.
(See fee schedule for a list of maintenance fees.)
Failure to pay the current maintenance fee on time may result in
expiration of the patent. A 6–month grace period is provided when the
maintenance fee may be paid with a surcharge. The grace period is the
6–month period immediately following the due date. The Patent and
Trademark Office does not mail notices to patent owners that maintenance
fees are due. If, however, the maintenance fee is not paid on time,
efforts are made to remind the responsible party that the maintenance
fee may be paid during the grace period with a surcharge.
Patents relating to some pharmaceutical inventions may be extended by
the Commissioner for up to five years to compensate for marketing delays
due to Federal premarketing regulatory procedures. Patents relating to
all other types of inventions may be extended for certain circumstances
as provided by law.