US patent maintenance fee due dates.

How US maintenance fee deadlines work

A US utility patent needs three maintenance fees to stay in force. Under 35 U.S.C. 41(b) they fall due 3.5, 7.5 and 11.5 years after grant. Under 37 CFR 1.362 each can be paid without surcharge from 3, 7 and 11 years after grant through 3 years 6 months, 7 years 6 months and 11 years 6 months. After that a six-month grace period runs through the 4th, 8th and 12th anniversary of the grant, and the surcharge in 37 CFR 1.20(h) applies.

If the fee is not paid by the end of the grace period, the patent expires (35 U.S.C. 41(b)(2)), at the end of the anniversary date shown in the last column of the result. A late payment can sometimes still be accepted through a petition under 37 CFR 1.378; see the link below. This tool does not assess whether such a petition would succeed.

Weekends. If the last day of a window falls on a Saturday or Sunday, the fee may be paid on the next business day (35 U.S.C. 21(b); 37 CFR 1.362(f)). This tool applies that to weekends and shows the rolled date. Federal holidays in the District of Columbia are not tabulated: if the date shown is one, add days until the next business day, and confirm with the USPTO.

Utility patents only. 35 U.S.C. 41(b)(3) says no fee may be established for maintaining a design or plant patent, so this does not apply to them. Maintenance fees apply to utility patents based on applications filed on or after December 12, 1980. Reissue patents count from the grant of the reissue only in the circumstances set by 37 CFR 1.362(h); check that rule for reissues.

Month-end grants. If the grant date is, for example, the 31st and the target month is shorter, the result shows the last day of that month and says so. That is the earlier date, so it is the safe one; confirm it with the USPTO.

Fee amounts are deliberately not shown because they change. Use the official fee schedule for current amounts, and for small and micro entity discounts.

Sources

• 37 CFR 1.362: time for payment of maintenance fees, windows, grace period and expiry.
• 35 U.S.C. 41(b): maintenance fees, grace period, no fee for design or plant patents.
• 35 U.S.C. 21(b): weekend and federal holiday roll-forward.
• 37 CFR 1.378: acceptance of delayed payment of a maintenance fee.
• USPTO fee schedule: current amounts (not reproduced here).

Rules as read from the sources above on September 30, 2026.