Maintenance Fees and Patent Expiration: Deadlines, Grace Periods, and Revival

A US utility patent can have a perfect term calculation — 20 years from the earliest effective filing date, plus PTA, minus any terminal disclaimer cap — and still expire prematurely if the patent owner fails to pay maintenance fees. Under 35 U.S.C. § 41(b), maintenance fees must be paid at three intervals during a patent's life: 3.5, 7.5, and 11.5 years after the grant date. Missing a payment causes the patent to expire at the end of the corresponding grace period. While revival is possible in some cases, it is not guaranteed and becomes more difficult the longer the lapse persists. For anyone evaluating patent term — whether for portfolio management, licensing, or freedom-to-operate analysis — maintenance fee status is a critical data point.

Scope: This article covers maintenance fee requirements for US utility patents under 35 U.S.C. § 41(b) and 37 CFR 1.362–1.378. Design patents, plant patents, and patents issued before December 12, 1980 are not subject to maintenance fees.

The Three Maintenance Fee Windows

Maintenance fees are structured as three escalating payments due at fixed intervals after the patent grant date:

First maintenance fee: Due 3.5 years after grant. The payment window opens 6 months before the due date (at the 3-year mark) and closes 6 months after (at the 4-year mark, with a surcharge for the final 6 months).

Second maintenance fee: Due 7.5 years after grant. Same window structure: opens at 7 years, closes at 8 years (with surcharge for the last 6 months).

Third maintenance fee: Due 11.5 years after grant. Opens at 11 years, closes at 12 years (with surcharge).

If the fee is paid within the first 6 months of the window (before the due date), no surcharge applies. If paid in the second 6 months (the grace period), a surcharge is added. If not paid by the end of the grace period, the patent expires.

Entity Status and Fee Amounts

Maintenance fee amounts depend on the patent owner's entity status:

Large entity: The standard fee for applicants that do not qualify for reduced fees.

Small entity: A 50% reduction is available under 37 CFR 1.27 for individuals, small businesses with fewer than 500 employees, and nonprofit organizations.

Micro entity: A 75% reduction is available under 35 U.S.C. § 123 for applicants meeting additional income and filing thresholds.

Fee amounts are adjusted periodically. The current fee schedule is published on the USPTO Fee Schedule page. As of 2025, the third maintenance fee for a large entity is several thousand dollars — a meaningful expense that some patent owners choose not to pay for patents they no longer consider valuable.

Misrepresenting entity status to obtain reduced fees can result in the patent being held unenforceable and, as of June 2025, may trigger monetary fines and PTA penalties. See the USPTO's notice on false entity status claims and our applicant delay guide for details.

How to Check Maintenance Fee Status

The USPTO provides a Maintenance Fee Lookup tool where you can enter a patent number and see the payment history, including which fees have been paid, which are upcoming, and whether any have lapsed.

Our Patent Expiration Calculator also checks maintenance fee status as part of the expiration calculation, flagging patents that have expired due to non-payment.

What Happens When a Maintenance Fee Lapses

If a maintenance fee is not paid by the end of the grace period, the patent expires under 35 U.S.C. § 41(b). The expiration is effective as of the date the grace period ended — not the original due date.

Once expired for non-payment, the patent is no longer enforceable. The patented invention enters the public domain as of the expiration date (though intervening rights may apply if the patent is later revived).

Revival After Lapse: Unintentional and Unavoidable

A patent that has expired due to non-payment of maintenance fees can potentially be revived under 37 CFR 1.378. The standard is that the delay in payment was unintentional.

A petition to accept late payment must include:

1. The required maintenance fee.
2. The surcharge under 37 CFR 1.20(i).
3. The petition fee.
4. A statement that the delay in payment was unintentional.

The USPTO does not require a detailed explanation of why the delay occurred, but the Director retains discretion to require additional information in appropriate cases. See MPEP § 2590.

Intervening Rights

When a patent is revived after a maintenance fee lapse, third parties who began using the invention during the lapse period may have intervening rights under 35 U.S.C. § 41(c)(2). These rights can allow continued use of the invention without liability for infringement. This is an important consideration for anyone relying on a lapsed patent's public domain status.

Maintenance Fees and Patent Term Calculations

Maintenance fee expiration is independent of the 20-year term calculation. A patent can "expire" multiple different ways:

• Term expiration: The 20-year base term (adjusted by PTA and capped by any terminal disclaimer) runs out.
• Maintenance fee expiration: The patent owner fails to pay a required maintenance fee.

The actual expiration is whichever comes first. When calculating patent expiration, both must be checked. A patent with 5 years of remaining term on paper is worthless if the second maintenance fee was never paid.

Worked Example: Patent Expiring Due to Unpaid Maintenance Fee

Common Mistakes

• Confusing the due date with the grace period deadline. The "due date" is 3.5/7.5/11.5 years after grant, but you have an additional 6 months (with surcharge) before the patent actually expires.
• Assuming maintenance fees are someone else's problem. If you acquired a patent through assignment or licensing, verify that fees were actually paid — don't assume the prior owner kept up.
• Not checking maintenance fees during freedom-to-operate analysis. A patent that appears threatening based on its claims and term may have already expired due to non-payment.
• Ignoring intervening rights after revival. If a lapsed patent is revived, third-party use during the lapse period may be protected.
• Misclaiming entity status. Filing as small or micro entity when the requirements are not met can result in the patent being unenforceable and, under the 2025 rules, monetary fines and PTA penalties.

Last reviewed: April 2026

Authorship: Written by the patentreply.ai editorial team. See our editorial methodology for how guides are drafted, sourced, and reviewed.

Legal disclaimer: This article is for informational purposes only and does not constitute legal advice. Consult a registered patent attorney or agent for advice specific to your situation. patentreply.ai is not a law firm.