In 2026, there are three payment deadlines for U.S. patent maintenance fees: 3.5 years, 7.5 years, and 11.5 years. Missing a payment means abandoning the patent rights—who should be responsible for keeping track of payment reminders?

If a U.S. patent maintenance fee is missed, the patent will lapse outright; it is not just a matter of paying a fine. The legal duty to monitor payment rests with the patent owner. The USPTO (United States Patent and Trademark Office) only sends reminders to the address of record, and neither loss in the mail nor failure to receive the reminder can be used as an excuse. In practice, we generally recommend putting the payment deadlines on an internal calendar and designating a foreign agent to provide dual reminders, rather than relying only on that letter from the USPTO.

The three nodes are not on the day of "year 3.5," but rather a window period calculated from the issue date

Maintenance fees for U.S. utility patents are paid only three times, respectively at 3.5 years, 7.5 years, and 11.5 years after grant. The "years" here are counted from the patent issue date, not from the filing date; many clients encountering this for the first time calculate from the filing date and end up off by a full year. The window period is also not a single day, but a payable range: the earliest payment can be made 6 months before the due date, and the latest within 6 months after the due date, but the latter falls within a grace period and incurs an additional surcharge. Taking the current fee schedule for 2026 as an example, the 3.5-year maintenance fee for a large entity is $2,000, plus a grace period surcharge of about $150; small entities pay half, and micro entities pay one quarter. Do not underestimate this surcharge—what is truly costly is the consequence of missing the grace period.

Legal consequences of failure to pay: the patent right lapses as of the original due date and cannot be remedied retroactively.

Under 35 U.S.C. §41(b) and §41(c), if the maintenance fee is not paid in full within the grace period, the patent right is deemed to expire as of the original fee due date. Note this "as of"—it is not counted from the day the grace period ends, but relates back to the last day of the window period. This means that during the period from missing the payment to discovery, the patent legally no longer exists, and third-party implementation does not constitute infringement. To restore it, one can only file a request for unintentional delay under 37 C.F.R. §1.378, which requires submitting a declaration and paying a restoration fee, and the USPTO will only accept it within a certain period after expiration. In practice, we generally advise: once a missed payment is discovered, file the restoration request immediately rather than first negotiating infringement with the other party, because acts during the lapse period are difficult to pursue.

The USPTO will send a reminder, but non-delivery is not its responsibility.

The USPTO does indeed send reminder letters to the patentee's registered address before each payment window, and also issues notifications through the Patent Center electronic system. However, federal regulations clearly provide that the obligation to pay is borne by the patentee, and USPTO reminders are courtesy reminders, not a legal obligation. Address changes, changes of agent, and invalid email addresses can all cause reminders to fail. Among the inquiries we have handled, the most common type is that an enterprise changed its U.S. agent firm, the old agent did not file a transfer-out registration, and the new agent did not take over payment monitoring, with both sides assuming the other was handling it, resulting in the 7.5-year installment quietly expiring. So do not treat reminders as insurance; they are only auxiliary.

Who should keep watch? The patentee, foreign agents, and the in-house IP role—all three are indispensable.

There is only one legally responsible party: the patent holder. At the execution level, however, responsibilities are usually split into three layers. The first layer is the patent holder itself, responsible for confirming the status of each case in the patent portfolio and the fee budget. The second layer is the overseas agent, responsible for sending formal reminders 60 to 90 days before the payment window and verifying the entity type (large/small/micro entity, which directly affects the amount). The third layer is the enterprise’s internal IP role or an external IP management platform, responsible for maintaining the ledger. If any of these three layers breaks down, the risk falls on the patent holder. Cross-border sellers should pay particular attention: if a U.S. patent is held through an applicant entity company, any change, deregistration, or acquisition of the corporate entity will affect who has the authority to pay fees and receive notices. Such structural issues must be clarified before payment and can be handled together with reference to the approach to overseas IP layout.

An error in the entity type means the payment was not made correctly, and it may still be invalid.

The amount of U.S. patent maintenance fees is divided into three tiers based on entity type: large entity, small entity (usually an enterprise or nonprofit organization with fewer than 500 employees), and micro entity (with stricter conditions). Small entity and micro entity status is not obtained automatically; it must be claimed at the time of payment and the conditions must be met. If the eligibility is no longer satisfied (for example, the enterprise has grown in size or the patent has been assigned to a large company) but payments continue to be made at the small entity rate, the USPTO has the right to require payment of the difference, and in serious cases this may affect patent validity. In practice, we generally recommend: reconfirm entity status before each payment, especially for patents that have undergone assignment, financing, or mergers and acquisitions. Such compliance actions are usually done together with routine trademark and patent maintenance, and can be combined withU.S. and EU Intellectual Property Legal Servicesto proceed according to the overall arrangements.

Once a patent expires, can it still be "revived"? The boundaries of restoration requests

Restoration is not unconditional. 37 C.F.R. §1.378 requires the applicant to declare that the entire delay was unintentional. The USPTO's standard for unintentional is relatively lenient, but the premise is that the cause of delay was indeed due to oversight rather than knowingly failing to pay. If the acceptance period for the restoration request has already passed, the patent right cannot be saved at all; one can only reapply, and refiling must confront a series of new issues such as prior art, publication date, and priority, with costs far higher than the original maintenance fee. Therefore, restoration is a remedy, not a routine operation. The truly prudent approach is still to manage payment nodes in advance.

2026 Practical Recommendations: Put Milestones in the Calendar and Assign Responsibility to Individuals.

How specifically to do it? First, immediately after obtaining the issue date, convert the three dates of 3.5 years, 7.5 years, and 11.5 years into calendar reminders for yourself, and note "payable 6 months in advance, 6-month grace after due date." Second, designate an internal responsible person and an overseas agency, with each setting reminders and cross-checking. Third, before payment, confirm whether the entity status and registered address are up to date. Fourth, if the patent portfolio covers multiple countries, do not focus only on the United States; annual fee rules in Europe, Japan, South Korea, and elsewhere differ, and they can be handled uniformly by a team capable of cross-jurisdictional coordination; refer to other countries' intellectual property legal services to understand the connecting methods. The amount of U.S. patent maintenance fees is not large, but the patent rights they correspond to may be highly valuable; using a small process to protect them is extremely cost-effective.

The foreign-related intellectual property team at Guangdong Zhiming Law Firm has long handled trademark, patent, and copyright matters in the United States, the European Union, and major jurisdictions. If you have any questions about the deadlines for paying U.S. patent maintenance fees, entity status determinations, or restoration after missed payments, please feel free to call our hotline at 0755-25986969 for consultation.

Disclaimer: This article is compiled based on publicly available U.S. patent laws and regulations and USPTO fee rules as of 2026 and is provided for general informational purposes only. It does not constitute legal advice for any specific case. U.S. patent maintenance fee amounts, grace period rules, and standards for requests for restoration may change with regulatory adjustments. For specific cases, please rely on the latest USPTO announcements and formal legal advice.