Which patents are subject to maintenance fees?
Maintenance fees are required for utility patents based on applications filed on or after December 12, 1980. As stated in MPEP 2504:
“Maintenance fees are required to be paid in all patents based on applications filed on or after December 12, 1980, except as noted in paragraph (b) of this section, to maintain a patent in force beyond 4, 8 and 12 years after the date of grant.”
Plant patents and design patents are exempt from maintenance fees.
To learn more:
Topics:
MPEP 2500 - Maintenance Fees,
MPEP 2504 - Patents Subject To Maintenance Fees,
Patent Law,
Patent Procedure