A patent expires on a date set by its type and filing history. A utility patent or plant patent expires 20 years after the non-provisional application was filed. A design patent filed on or after May 13, 2015 expires 15 years after the patent was granted.1United States Patent and Trademark Office. Manual of Patent Examining Procedure Section 15052Office of the Law Revision Counsel. 35 USC 154 – Contents and Term of Patent Those are the baselines. The real expiration date for any particular patent can be earlier if a maintenance fee was missed, or later if the USPTO or a regulatory agency took extra time to clear the invention for market.
The Standard Term by Patent Type
Federal law recognizes three kinds of patents, and each measures its term differently.
Utility patents cover how things work: machines, chemical compounds, manufacturing processes. The 20-year clock runs from the filing date of the non-provisional application, not from the grant date. An application filed January 1, 2010 would carry a baseline expiration of January 1, 2030.2Office of the Law Revision Counsel. 35 USC 154 – Contents and Term of Patent
Plant patents, which cover new varieties of asexually reproduced plants, follow the same 20-year-from-filing rule.3United States Patent and Trademark Office. Manual of Patent Examining Procedure – Patent Term
Design patents protect how something looks rather than how it functions. Because the 15-year term starts at grant rather than filing, review time at the USPTO does not eat into the exclusivity period.1United States Patent and Trademark Office. Manual of Patent Examining Procedure Section 1505
One common source of confusion: a provisional application does not start the 20-year clock. The term runs from the non-provisional filing date, so filing a provisional to lock in an earlier priority date does not cost you patent life.3United States Patent and Trademark Office. Manual of Patent Examining Procedure – Patent Term
What Pushes the Expiration Date Later
Two separate mechanisms can extend the standard term. Both are additive to the baseline calculation.
Patent Term Adjustment for USPTO Delays
When the USPTO takes too long to process an application, the patent holder receives extra days of patent life on a day-for-day basis. Under 35 U.S.C. § 154(b), the most common triggers are the office failing to issue a first response within 14 months of filing, and failing to grant the patent within three years of the actual filing date.2Office of the Law Revision Counsel. 35 USC 154 – Contents and Term of Patent Adjustments often add months, and sometimes years. The number of days added is printed on the front page of the granted patent.
Patent Term Extension for Regulatory Delays
Drugs, medical devices, food additives, and some animal health products cannot be sold until they clear a separate government approval process, which can consume years of patent life before any commercial use is possible. Under 35 U.S.C. § 156, the patent holder can recover some of that lost time. Two caps apply: the extension cannot exceed five years, and the total remaining patent life after the extension cannot exceed 14 years from the product’s approval date.4Office of the Law Revision Counsel. 35 USC 156 – Extension of Patent Term For pharmaceutical patents especially, the 14-year cap often controls the outcome.
What Pulls the Expiration Date Earlier
Missed Maintenance Fees on Utility Patents
A utility patent will end before its 20-year term if the owner fails to pay maintenance fees at 3.5 years, 7.5 years, and 11.5 years after the grant date. The fees escalate at each step and depend on entity size, with small entities (generally individuals, nonprofits, and businesses with no more than 500 employees) and micro entities paying reduced amounts.5United States Patent and Trademark Office. USPTO Fee Schedule6United States Patent and Trademark Office. Save on Fees With Small and Micro Entity Status
Miss a payment window, and there is a six-month grace period with a surcharge. Miss the grace period, and the patent expires and the invention enters the public domain.7Office of the Law Revision Counsel. 35 USC 41 – Patent Fees The 11.5-year fee is the largest, and many utility patents are deliberately abandoned at that point because the owner has decided the remaining protection is not worth the cost.
Design patents and plant patents carry no maintenance fees. Once granted, they run their full term with no further payments required.7Office of the Law Revision Counsel. 35 USC 41 – Patent Fees Early lapse for non-payment is only a utility patent concern.
Terminal Disclaimers
When an applicant files multiple patents on closely related ideas, the USPTO may require a terminal disclaimer that forces the later patent to expire on the same date as the earlier one. The disclaimer runs with the patent through any sale or assignment, so a later owner cannot undo it.8United States Patent and Trademark Office. Manual of Patent Examining Procedure Section 1490 – Disclaimers If you are calculating a patent’s expiration and a terminal disclaimer appears on the record, the tied-earlier date controls.
Older Patents Filed Before June 8, 1995
Patents filed before the United States adopted the Uruguay Round Agreements Act used a different rule: 17 years from grant rather than 20 years from filing. Patents that were in force on June 8, 1995, or that resulted from applications filed before that date, get whichever term is longer.3United States Patent and Trademark Office. Manual of Patent Examining Procedure – Patent Term Most such patents have long since expired, but if you are researching one, calculate both dates and use the later.
Reviving a Patent That Expired for Non-Payment
A patent that lapsed because a maintenance fee was missed can sometimes be brought back. The owner petitions the USPTO to accept a delayed payment, submitting the overdue maintenance fee, a separate petition fee, and a statement that the delay was unintentional.9United States Patent and Trademark Office. Acceptance of Delayed Payment of Maintenance Fee in Expired Patent to Reinstate Patent The petition fee is higher when the delay exceeds two years, and a separate petition and fee are needed for each missed window.5United States Patent and Trademark Office. USPTO Fee Schedule
Revival has a catch. Anyone who began making, using, or selling the invention during the lapse period may have intervening rights: a court can allow that competitor to continue existing activity and, in some cases, to continue manufacturing products for which substantial preparations were made during the lapse.7Office of the Law Revision Counsel. 35 USC 41 – Patent Fees The patent comes back on paper, but the monopoly may not fully come back with it.
How to Confirm the Exact Date for a Specific Patent
The USPTO does not officially calculate expiration dates. Working it out means gathering several pieces of information from the patent record.10United States Patent and Trademark Office. Patent Term Calculator
Start by pulling up the patent in the USPTO Patent Public Search database at ppubs.uspto.gov. The front page shows the filing date, the grant date, and any patent term adjustment measured in days.11United States Patent and Trademark Office. Patent Public Search Calculate the baseline from filing date (utility, plant) or grant date (design), then add any adjustment days.
Check whether a patent term extension applies. For patents covering drugs or medical devices, the USPTO maintains a list of patents that received extensions under 35 U.S.C. § 156.12United States Patent and Trademark Office. Patent Term Extension Under 35 USC 156 Look for any terminal disclaimer on the record as well, since that would shorten the term to match a related patent.
For utility patents, verify the maintenance fee history. The USPTO’s fee inquiry system, accessible through the Patent Center portal, shows whether the 3.5-year, 7.5-year, and 11.5-year payments were made. A status of “lapsed” means the patent already expired regardless of how much time was left on the 20-year term.
The USPTO also publishes a downloadable patent term calculator spreadsheet that walks through the same inputs. The agency notes that the tool is only an educational estimate.10United States Patent and Trademark Office. Patent Term Calculator For decisions with money at stake, confirming the date with a patent attorney is worth the cost.