A utility patent lasts 20 years from its earliest non-provisional filing date, a design patent lasts 15 years from the date it is granted, and a plant patent lasts 20 years from its filing date. Those are the baseline terms that answer how long patents are valid, but the actual lifespan of any given patent depends on whether the owner pays required fees on time, whether the USPTO caused processing delays, whether the invention needed regulatory approval before it could be sold, and whether anyone successfully challenges the patent’s validity.
Utility Patents Run 20 Years From the Filing Date
Utility patents cover the functional side of an invention: a new process, machine, manufactured item, or chemical composition. The term runs 20 years from the date the earliest non-provisional application was filed in the United States.1Office of the Law Revision Counsel. 35 US Code 154 – Contents and Term of Patent; Provisional Rights The clock starts on the filing date, not the grant date. That matters, because examination often takes two to four years, and every one of those years is spent inside your 20-year window.
Provisional applications are where people get confused. Filing a provisional gives you an early priority date and 12 months to file the full non-provisional application, but the 20-year clock does not begin at the provisional filing. It begins at the non-provisional filing. Priority claims under the Paris Convention or the Patent Cooperation Treaty also don’t shorten the term.1Office of the Law Revision Counsel. 35 US Code 154 – Contents and Term of Patent; Provisional Rights So a provisional effectively buys you an extra year of priority without eating into the 20.
Design Patents Run 15 Years From the Grant Date
Design patents protect the ornamental appearance of a manufactured item rather than how it functions. A distinctive shape for a phone case, a unique pattern applied to furniture: that visual element is what a design patent covers. The term is 15 years measured from the date the patent is granted.2Office of the Law Revision Counsel. 35 US Code 173 – Term of Design Patent Because the term starts at grant rather than filing, examination delays don’t shorten your protection.
The 15-year term applies to applications filed on or after May 13, 2015. Design applications filed before that date carry a 14-year term from grant.3United States Patent and Trademark Office. Manual of Patent Examining Procedure – 1505 Term of Design Patent Design patents also require no maintenance fees at any point during their term.4Office of the Law Revision Counsel. 35 US Code 41 – Patent Fees; Patent and Trademark Search Systems Once granted, they simply run for their full 15 years.
Plant Patents Run 20 Years From the Filing Date
Plant patents cover new and distinct varieties of plants reproduced asexually, through methods like grafting or cuttings rather than seeds. The term is 20 years from the earliest non-provisional filing date, the same rule that governs utility patents.1Office of the Law Revision Counsel. 35 US Code 154 – Contents and Term of Patent; Provisional Rights Like design patents, plant patents carry no maintenance fee obligation.4Office of the Law Revision Counsel. 35 US Code 41 – Patent Fees; Patent and Trademark Search Systems
Utility Patents Need Maintenance Fees to Stay Alive
This is where many utility patents quietly die before their 20 years are up. A utility patent doesn’t stay in force automatically. The owner has to pay three rounds of maintenance fees, and missing any one of them ends the patent. Design and plant patents are exempt.4Office of the Law Revision Counsel. 35 US Code 41 – Patent Fees; Patent and Trademark Search Systems
For a large entity (generally a company with more than 500 employees), the fees are:5United States Patent and Trademark Office. USPTO Fee Schedule
- $2,150 at 3.5 years after grant
- $4,040 at 7.5 years after grant
- $8,280 at 11.5 years after grant
Miss a due date and you have a six-month grace period to pay the fee plus a $540 surcharge.5United States Patent and Trademark Office. USPTO Fee Schedule After the grace period, the patent expires. Over the full 20-year life of a large-entity utility patent, that’s $14,470 in maintenance fees alone, before any surcharges. Many owners deliberately let later-stage patents lapse when the underlying invention no longer justifies the escalating cost.
Small and Micro Entity Discounts
The USPTO reduces most patent fees for smaller applicants. Small entities pay 60% less than the standard rate. Micro entities pay 80% less.
Small entity maintenance fees are $860 at 3.5 years, $1,616 at 7.5 years, and $3,312 at 11.5 years.5United States Patent and Trademark Office. USPTO Fee Schedule Micro entity fees are $430, $808, and $1,656 at the same intervals.
Small entity status generally covers independent inventors, nonprofits, and businesses with no more than 500 employees. Micro entity status requires small entity qualification plus two further conditions: neither you nor any co-inventor can have been named on more than four previously filed patent applications (with some exceptions), and your gross income must fall below a threshold set annually by the USPTO. The discounts apply to filing, examination, and issue fees as well as maintenance, so it’s worth confirming eligibility early.
Extra Days for USPTO Delays: Patent Term Adjustment
If the USPTO drags out your application, you can get days added back to your patent term through Patent Term Adjustment. This applies only to utility and plant patents. One day of extra patent life is added for each day of qualifying delay, and the USPTO calculates it automatically when the patent issues.
Delays that trigger an adjustment include:1Office of the Law Revision Counsel. 35 US Code 154 – Contents and Term of Patent; Provisional Rights
- The USPTO takes more than 14 months from filing to issue a first substantive action or notice of allowance
- The USPTO takes more than four months to respond after you reply to an office action or file an appeal
- The USPTO takes more than four months to issue the patent after you pay the issue fee and satisfy all requirements
- Total pendency runs longer than three years, excluding time spent on applicant-requested delays, appeals, and continued examination requests
The total adjustment appears on the face of the issued patent.6United States Patent and Trademark Office. Manual of Patent Examining Procedure – 2733 Patent Term Adjustment Determination Adjustments of a few hundred days are common. Any delays you caused yourself, such as late responses, are subtracted from the total. If you think the calculation is wrong, you can request reconsideration from the USPTO or challenge it in federal court.
Extra Years for Regulated Products: Patent Term Extension
Some patented products can’t reach the market until they clear regulatory review. Drugs, medical devices, food additives, and certain veterinary products all go through approval processes that consume years of patent life. Patent Term Extension compensates for that lost time.7Office of the Law Revision Counsel. 35 US Code 156 – Extension of Patent Term
The extension has two hard limits. It cannot exceed five years, and the total effective patent life after regulatory approval cannot exceed 14 years.7Office of the Law Revision Counsel. 35 US Code 156 – Extension of Patent Term Only one patent per approved product qualifies, and the owner must apply within 60 days of approval. The provision matters most in pharmaceuticals, where clinical trials and FDA review routinely consume a decade or more of a drug patent’s 20-year term.
Voluntarily Shortening a Patent: Terminal Disclaimers
A patent owner can shorten a patent’s term by filing a terminal disclaimer. This typically happens when an inventor owns two or more patents on closely related subject matter with different expiration dates. To resolve what’s known as double patenting, the owner disclaims the tail end of the later-expiring patent so both expire on the same day.8Office of the Law Revision Counsel. 35 US Code 253 – Disclaimer
Terminal disclaimers usually come up during prosecution at the USPTO’s request, and they carry a condition. A patent subject to a terminal disclaimer is enforceable only while it remains commonly owned with the earlier patent, or while both patents are licensed to the same party.9United States Patent and Trademark Office. Manual of Patent Examining Procedure – 1490 Disclaimers If ownership splits, the disclaimed patent can become unenforceable.
Validity Challenges That Can End a Patent Early
Even after grant, third parties can challenge a patent’s validity through proceedings at the USPTO’s Patent Trial and Appeal Board. An Inter Partes Review lets anyone argue that a patent’s claims should be canceled for lack of novelty or obviousness in light of prior patents and publications. If the board agrees, it cancels some or all of the claims, which ends protection for those inventions before the term would otherwise run. A Post-Grant Review works similarly but reaches a broader set of invalidity grounds and must be filed within nine months of the patent’s grant. Both proceedings are a routine consideration in technology and pharmaceutical patent strategy.
Reinstating a Patent That Lapsed for Non-Payment
A utility patent that expired because a maintenance fee went unpaid can sometimes be reinstated. You file a petition with the USPTO showing that the delay in payment was unintentional, and you pay the overdue maintenance fee along with a petition fee.10United States Patent and Trademark Office. Manual of Patent Examining Procedure – 2590 Acceptance of Delayed Payment of Maintenance Fee in Expired Patent to Reinstate Patent
The petition fee depends on how long you waited. Delays of two years or less cost $2,260 for a large entity, $904 for a small entity, or $452 for a micro entity. Delays over two years cost $3,000, $1,200, or $600, respectively.5United States Patent and Trademark Office. USPTO Fee Schedule If more than one maintenance window was missed, each requires its own petition and fee.
Reinstatement carries a catch. Anyone who began making or using the invention while the patent was expired may have intervening rights that let them continue. The reinstated patent is treated as if it never lapsed, but those third-party rights survive. The longer the patent sits expired, the harder reinstatement is to justify and the more intervening rights accumulate.
What Happens When a Patent Expires
Once the term ends or the patent lapses for non-payment without reinstatement, the claimed invention enters the public domain. Anyone can make, use, or sell it, and the former owner loses the right to sue for infringement going forward.
Expiration of one patent doesn’t always clear the field. Other patents held by the same owner or by different owners may cover overlapping features and remain enforceable on their own timelines. Trademark, trade dress, and trade secret protections can also outlast a patent. A review of related intellectual property is worth doing before treating an expired patent as an open door.