What maintenance fees are and when they apply
US utility patents require periodic maintenance fees to remain in force beyond the first 4 years after grant. Under 35 U.S.C. § 41, three maintenance fees are due: at 3.5, 7.5, and 11.5 years after the patent grant date. Each maintenance fee must be paid within the 6-month window following those benchmarks. If not paid within the window, there is an additional 6-month grace period (with a surcharge). Failure to pay within the grace period causes the patent to expire — the invention enters the public domain. Maintenance fees apply only to utility patents; design patents and plant patents do not require them. The maintenance fee system was introduced in 1980 to generate USPTO revenue and to let unneeded patents lapse into the public domain, reducing the number of patents patent holders must actively maintain.
Fee schedule and entity status
Maintenance fee amounts depend on entity status. Large entities pay full fees; small entities (fewer than 500 employees, universities, certain nonprofits) pay half; micro-entities (meeting income and prior-application limits) pay a quarter. As of 2024: the 3.5-year fee is approximately $2,000 (large), $1,000 (small), and $500 (micro). The 7.5-year fee is approximately $3,760/$1,880/$940. The 11.5-year fee is approximately $7,700/$3,850/$1,925. Late surcharges apply within the grace period ($160/$80/$40). Entity status can be updated at the time of maintenance fee payment — if a company grew from a small to large entity, it must pay large entity fees going forward. Overclaiming small or micro-entity status when ineligible is a serious issue that can affect patent enforceability.
The grace period and late payment
If a maintenance fee is not paid during the 6-month payment window after each anniversary, there is a 6-month grace period. During this grace period, the fee can still be paid with a late surcharge. The patent remains technically in force during the grace period (it has not yet expired). After the grace period ends without payment, the patent expires. The USPTO sends courtesy reminder notices to the correspondence address on record, but is not legally required to do so. Many patents have lapsed because notices were sent to an outdated address. Best practice: maintain an accurate correspondence address with the USPTO and independently track maintenance fee deadlines in a docketing system, not just relying on USPTO notices.
Reinstatement of an expired patent
A patent that expired for non-payment of maintenance fees can be reinstated under 37 C.F.R. § 1.378 if the delay was unintentional. The patentee files a petition to accept the delayed payment, submits the missed maintenance fee plus the late surcharge, and provides a statement that the delay was unintentional. There is no regulatory time limit for filing a reinstatement petition, but the USPTO scrutinizes petitions more carefully for long delays and the burden of showing unintentional delay increases over time. Reinstated patents are treated as though they never expired for enforcement purposes — but parties who began infringing during the expiration period may have acquired intervening rights (the right to continue acts that began during the expiration gap). Patentees should evaluate whether the value of reinstated coverage outweighs the cost and risk of the reinstatement petition.
Strategic maintenance fee management
Maintenance fees represent an ongoing cost commitment that must be weighed against a patent's commercial value. A patent covering a product currently being sold at significant margin is worth maintaining; a patent covering technology that was never commercialized or that has been superseded is often not. Many companies conduct periodic patent portfolio reviews to identify patents approaching maintenance fee deadlines and decide whether to pay or allow them to expire. Decisions to let patents lapse can be strategic: allowing a patent to expire (and enter the public domain) can be a competitive tool (preventing competitors from obtaining patents on the same subject matter), a cost management decision, or simply a recognition that the patent no longer serves business objectives. Portfolio management software and outside patent counsel typically help companies track maintenance fee deadlines across large patent portfolios.
Maintenance fees for PCT and foreign patents
Maintenance fee requirements vary by country. In addition to US maintenance fees, a company holding an international patent portfolio must also pay annuities or renewal fees in foreign countries. European patents (granted by the EPO) require annual renewal fees in each designated country after grant. Japanese patents require annuities from the third year after filing. Chinese patents require annuities from the second year. Most other countries have similar annual fee requirements. Unlike the US system (which has only three scheduled maintenance fees over the full patent term), many foreign countries require annual payments throughout the patent's life. International patent portfolio management therefore involves tracking hundreds of renewal fee deadlines across many jurisdictions — typically handled by patent annuity services or outside IP counsel with docketing systems.
Frequently Asked Questions
When are US patent maintenance fees due?
US utility patent maintenance fees are due at three payment windows: (1) 3.5 years after the patent grant date — window is 3 years to 3 years 6 months after grant; (2) 7.5 years after grant — window is 7 years to 7 years 6 months after grant; (3) 11.5 years after grant — window is 11 years to 11 years 6 months after grant. If the maintenance fee is not paid within the 6-month payment window, there is a 6-month grace period (from the end of the payment window) during which the fee can still be paid with a surcharge. If not paid during the grace period, the patent expires. Maintenance fees are paid through the USPTO's fee payment system. The USPTO sends courtesy reminders but is not required to do so — the patentee is responsible for tracking deadlines.
What are the current USPTO maintenance fee amounts?
USPTO maintenance fees for utility patents (2024 fee schedule): Due at 3.5 years — large entity: $2,000; small entity: $1,000; micro-entity: $500. Due at 7.5 years — large entity: $3,760; small entity: $1,880; micro-entity: $940. Due at 11.5 years — large entity: $7,700; small entity: $3,850; micro-entity: $1,925. Late surcharge (within grace period) — large entity: $160; small entity: $80; micro-entity: $40. USPTO fees are updated periodically; verify current fees at the USPTO fee schedule before making payments. Entity status determines the fee: large entity is the default; small entity requires a verified assertion of small entity status (fewer than 500 employees, certain universities and nonprofits); micro-entity has stricter requirements (income limits and 4-application limit).
What patents require maintenance fees?
Maintenance fees are required only for US utility patents. Design patents (D numbers, filed under 35 U.S.C. § 171) do NOT require maintenance fees — they remain in force for their full 15-year term (for applications filed after May 13, 2015) without any ongoing fees. Plant patents (PP numbers) also do NOT require maintenance fees. Utility patents (US numbers) require all three maintenance fees to remain in force for their full 20-year term from the earliest non-provisional filing date. For patents resulting from PCT applications, the 20-year term runs from the international filing date of the PCT application. Note: the 20-year term is measured from the US non-provisional filing date (or PCT filing date for PCT-origin patents), not from the grant date. This means patents that spent many years in examination may have less than 20 years of post-grant term.
Can an expired patent be reinstated?
Yes, an expired US patent can be reinstated if the failure to pay was unintentional. Under 35 U.S.C. § 41(c), the USPTO can accept a delayed maintenance fee payment after the grace period if: (1) the delay was unintentional; and (2) a petition to accept the delayed payment is filed with the missing maintenance fee, the surcharge, and a statement that the delay was unintentional. There is no absolute deadline for reinstatement, but the USPTO is less likely to grant petitions for very long delays. Importantly, there is an intervening rights issue: a party that begins making, using, selling, or importing a product between the date the patent expired and the date it is reinstated may have acquired intervening rights — specifically, continued use rights for actions that began during the expiration period. This is similar to the intervening rights doctrine in patent reissue.
Does not paying maintenance fees make the patent expire before 20 years?
Yes. A utility patent that is not maintained through timely maintenance fee payments expires before its 20-year maximum term. For example: if maintenance fees due at 7.5 years are not paid (even within the grace period), the patent expires at the end of the 8-year mark (end of the grace period). Once expired for non-payment, the patent enters the public domain — the invention described in the patent can be freely used, made, and sold without the former patentee's permission. The former patentee retains ownership but no longer has enforceable exclusive rights. Many patents deliberately expire early for non-payment when the invention no longer has commercial value — it is not cost-effective to pay thousands of dollars in maintenance fees to maintain a patent covering a product that is no longer being sold.