The patent maintenance fee grace period is a six-month window after each scheduled payment deadline during which you can still pay the fee, keep your patent alive, and avoid expiration by adding a surcharge of $108 to $540 on top of the base fee. The patent remains fully enforceable throughout this window. It expires only if the last day of the grace period passes without payment.1United States Patent and Trademark Office. Acceptance of Delayed Payment of Maintenance Fee in Expired Patent to Reinstate Patent
When Each Grace Period Runs
Utility patents require three maintenance payments over a 20-year term. Each has a six-month surcharge-free window, followed immediately by a six-month grace period. The grace periods are:2eCFR. 37 CFR 1.362 – Time for Payment of Maintenance Fees
- First fee: from 3 years 6 months through the 4th anniversary of the grant date.
- Second fee: from 7 years 6 months through the 8th anniversary of the grant date.
- Third fee: from 11 years 6 months through the 12th anniversary of the grant date.
The deadline is the anniversary date itself. There is no built-in extension, and you cannot pay before the surcharge-free window opens.
What It Costs
Late payment during the grace period requires the base maintenance fee plus a flat surcharge tied to your entity status:3eCFR. 37 CFR 1.20 – Post-Issuance Fees
- Large entity: $540
- Small entity: $216
- Micro entity: $108
Combined totals under the April 2026 USPTO fee schedule work out as follows:4United States Patent and Trademark Office. USPTO Fee Schedule
First fee (3.5-year interval) with grace surcharge:
- Large entity: $2,150 + $540 = $2,690
- Small entity: $860 + $216 = $1,076
- Micro entity: $430 + $108 = $538
Second fee (7.5-year interval) with grace surcharge:
- Large entity: $4,040 + $540 = $4,580
- Small entity: $1,616 + $216 = $1,832
- Micro entity: $808 + $108 = $916
Third fee (11.5-year interval) with grace surcharge:
- Large entity: $8,280 + $540 = $8,820
- Small entity: $3,312 + $216 = $3,528
- Micro entity: $1,656 + $108 = $1,764
The USPTO will not process the payment if the surcharge is missing or the amount is wrong. If your entity status has changed since the patent was granted, update it before paying.
Is the Patent Enforceable During the Grace Period?
Yes. The patent stays in force for the full six months of the grace period. Your enforcement rights against infringers are unaffected during that time.1United States Patent and Trademark Office. Acceptance of Delayed Payment of Maintenance Fee in Expired Patent to Reinstate Patent Expiration is triggered only by the grace period ending without a valid payment on file.
How to Pay Before the Deadline
You need the patent number and the corresponding application number for any maintenance fee payment.5United States Patent and Trademark Office. Maintain Your Patent The fastest route is the USPTO Patent Maintenance Fees Storefront, which requires a USPTO.gov account. Once you enter the patent and application numbers, the system calculates the total balance including the surcharge and accepts credit cards, debit cards, electronic funds transfers, and USPTO deposit accounts. You receive an electronic receipt when the transaction completes.
You can also fax the Maintenance Fee Transmittal Form (PTO/SB/45) with the Credit Card Payment Form to 571-273-6500, or mail the transmittal form with a check or money order to:
Mail Stop Maintenance Fee
Director of the U.S. Patent and Trademark Office
P.O. Box 1450
Alexandria, VA 22313-1450
Anyone can pay on the patent owner’s behalf. No formal authorization is required, which is why many patent holders use third-party annuity services to track deadlines, especially if they hold multiple patents.
Do Not Rely on a USPTO Reminder
The USPTO has no legal duty to notify you that a fee is due. Any reminders it sends are courtesies, and errors or delays do not excuse a late payment.6United States Patent and Trademark Office. MPEP Section 2575 – Notices Those courtesy reminders are not sent until after the surcharge-free window has already closed and the grace period has begun. Reminders go to the fee address on file under 37 CFR 1.363, so keeping that address current is essential. Tracking the deadline is your responsibility.
What Happens If You Miss the Grace Period
Once the grace period ends without payment, the patent expires. Expiration is not always permanent. You can petition the USPTO to accept a delayed payment if you can state that the delay was unintentional.7eCFR. Acceptance of Delayed Payment of Maintenance Fee in Expired Patent to Reinstate Patent
The petition must include the overdue maintenance fee, a signed statement that the delay was unintentional, and a separate petition fee. Under the April 2026 fee schedule, the petition fee is $2,260 within two years of expiration and $3,000 after that.4United States Patent and Trademark Office. USPTO Fee Schedule The petition fee is on top of the maintenance fee and grace surcharge. The Director may request more information if there is reason to question whether the delay was unintentional.
Revival also comes with a real risk to your enforcement rights. If a third party began making, using, or selling the invention after the grace period ended and before the USPTO accepted your late payment, federal law may allow that party to continue. A court can permit continued manufacturing where the party made substantial preparations during the lapse.8Office of the Law Revision Counsel. 35 U.S. Code 41 – Patent Fees; Patent and Trademark Search Systems The longer the patent stays expired, the more likely these intervening rights take hold, which is a strong reason to act inside the grace period rather than counting on revival.