How Long Does a Patent Last?

Introduction

How long does a patent last? In the United States, utility and plant patents generally have a term of up to 20 years from the applicable filing date, while design patents generally last 15 years from the date they are granted. The actual expiration date can differ depending on the patent's filing history, applicable adjustments or extensions, disclaimers, and other legal factors.

Understanding how long a patent lasts is important when developing a new product, planning to commercialize an invention, licensing intellectual property, or researching whether an existing patent may have expired.

This guide explains how long each type of U.S. patent lasts, when the patent term begins, what can cause a patent to expire early, and how to research the expiration date of a particular patent.

Quick Answer: How Long Does a Patent Last?

The general patent terms in the United States are:

• Utility patents: Generally up to 20 years from the applicable U.S. filing date, subject to adjustments, extensions, disclaimers, maintenance requirements, and other applicable rules.

• Plant patents: Generally up to 20 years from the applicable U.S. filing date, subject to applicable term rules and limitations.

• Design patents: Generally 15 years from the grant date for applications filed on or after May 13, 2015. Design patents from applications filed before that date generally have a 14-year term from grant.

These are general rules, not guarantees that every patent will remain in force for its entire ordinary term. Older patents and patents with unusual filing histories may be subject to different rules.

How Long Does Each Type of Patent Last?

The type of patent is one of the most important factors in determining how long patent protection lasts.

How Long Does a Utility Patent Last?

A U.S. utility patent generally has a term that ends 20 years from the applicable filing date. For many patents, this is the filing date of the nonprovisional application. If the application claims the benefit of certain earlier related U.S. applications, the term may instead be measured from the earliest qualifying application in that chain.

Utility patents protect new and useful processes, machines, articles of manufacture, compositions of matter, and qualifying improvements.

For example, an inventor who develops a new mechanical locking mechanism may seek a utility patent to protect the mechanism's functional features.

Several factors can affect how long a particular utility patent remains in force:

• Related applications: An earlier qualifying U.S. application may determine the date from which the 20-year term is measured.

• Patent term adjustment: Certain delays attributable to the USPTO may result in additional term under the applicable rules.

• Patent term extension: Certain qualifying patents may receive an extension under specific statutory provisions.

• Terminal disclaimers: A terminal disclaimer can limit a patent's term.

• Maintenance fees: Failure to pay required maintenance fees can cause a utility patent to expire before the end of its ordinary term.

Utility patent owners generally must pay maintenance fees at specified intervals after the patent is granted to keep the patent in force.

Learn more about the differences between patent types in our guide to Utility Patent vs. Design Patent.

How Long Does a Design Patent Last?

For U.S. design patent applications filed on or after May 13, 2015, the patent term is 15 years from the date the patent is granted.

Design patents protect the ornamental appearance of an article, rather than its functional features. Depending on the product, this can include its shape, surface ornamentation, or overall visual appearance.

For example, a designer may seek a design patent for the distinctive appearance of a lamp, chair, or consumer product.

Design patents issued from applications filed before May 13, 2015, generally have a 14-year term from the grant date. The application filing date determines which rule applies, not simply the date the patent was issued.

Design patents do not require periodic maintenance fees to remain in force.

For a more detailed comparison of functional and ornamental protection, see our guide to Utility Patent vs. Design Patent.

How Long Does a Plant Patent Last?

A U.S. plant patent generally has a term that ends 20 years from the applicable U.S. filing date, subject to the rules that apply to the particular application.

Plant patents protect qualifying new and distinct plant varieties that have been invented or discovered and asexually reproduced.

Plant patents do not require maintenance fees. However, the term of a particular plant patent may still be affected by its filing history and other applicable legal provisions.

When Does the Patent Term Start?

One common source of confusion is the difference between a patent's filing date and its grant date.

For most modern U.S. utility and plant patents, the term is generally measured from the applicable filing date, even though the patent is not granted until later. The patent's enforceable rights as an issued patent generally arise upon grant, but the time spent waiting for the patent to be issued generally counts toward its ordinary term.

For design patents filed on or after May 13, 2015, the 15-year term is measured from the grant date.

This difference matters because patent applications can take years to be examined and approved. A utility patent that takes several years to issue generally does not receive a fresh 20-year term beginning on the grant date.

Does a Provisional Patent Application Start the 20-Year Clock?

A provisional patent application is not an issued patent and does not itself provide an enforceable patent grant.

A provisional application generally lasts 12 months. An inventor who wants to pursue patent protection based on a provisional application must file an appropriate follow-on application within the applicable period and meet the requirements for claiming the provisional application's benefit.

The provisional filing date itself does not count as the starting date for the standard 20-year term of a resulting utility patent. That term is generally measured from the applicable nonprovisional filing date or the earliest qualifying related nonprovisional application date.

Simply filing a provisional application does not guarantee that a patent will be granted.

If you are considering this route, see our guide to Provisional vs. Non-Provisional Patents.

Can a Patent Expire Before Its Full Term?

Yes. A patent can expire before the end of its ordinary term. The reasons depend on the patent type and its history.

1. Unpaid Maintenance Fees

Utility patent owners generally must pay maintenance fees at 3.5, 7.5, and 11.5 years after the patent is granted.

A six-month grace period follows each maintenance-fee due date. If the required fee and applicable surcharge are not paid within the permitted period, the patent can expire for failure to pay.

Certain procedures may allow a lapsed patent to be reinstated in qualifying circumstances, but reinstatement is not automatic.

Design and plant patents do not require maintenance fees.

2. An Earlier Related Application

A utility or plant patent may claim the benefit of an earlier related U.S. application, such as a qualifying continuation or divisional application.

When the applicable rules require it, the earliest qualifying filing date in the application chain determines the ordinary 20-year term. This means the expiration date cannot always be calculated by adding 20 years to the filing date shown most prominently on a patent document.

Not every earlier application or foreign priority date determines the patent term. The relationship between the applications and the specific legal provisions involved matter.

3. Patent Term Adjustments and Extensions

Some patents qualify for a patent term adjustment because of certain delays during examination by the USPTO. Other qualifying patents may receive a patent term extension under specific laws, including provisions relating to certain regulatory review delays.

These adjustments and extensions are subject to legal requirements and limitations. They do not automatically apply to every patent.

4. Terminal Disclaimers and Other Limitations

A terminal disclaimer can limit the term of a patent, including by specifying an earlier expiration date. The effect depends on the terms of the disclaimer and the applicable law.

Other legal circumstances, including certain court decisions or administrative proceedings, may also affect a patent's status or enforceability.

For these reasons, the ordinary 20-year or 15-year term should be treated as a starting point for research, not a definitive expiration date for a particular patent.

How Can You Find Out When a Patent Expires?

If you want to determine whether a specific patent is still in force, start by identifying the patent and reviewing its official records.

The USPTO Patent Public Search is a useful starting point for finding U.S. patents and published patent applications.

Use these steps to begin your research:

1. Find the patent. Search by patent number, inventor name, or other identifying information.

2. Identify the patent type. Determine whether the patent is a utility, design, or plant patent.

3. Review the relevant filing dates. Look for related applications and qualifying earlier filing dates that may affect the term.

4. Check the patent's maintenance-fee history. For utility patents, verify whether required maintenance fees were paid.

5. Look for adjustments, extensions, and disclaimers. These may change the expected expiration date.

6. Confirm the patent's status using official records. If the date has legal or commercial consequences, consider consulting a registered patent attorney or agent.

The USPTO also provides a Patent Term Calculator to help estimate patent expiration dates. The calculation may require details about the patent's application history and other factors.

The calculator is a research aid, not a definitive legal determination. Review the relevant records and applicable rules before relying on an estimated expiration date.

Free Download: Patent Term & Expiration Planning Sheet

Trying to keep track of patent dates, maintenance fees, and expiration information? A printable worksheet can help you organize the details you need to research.

Our free Patent Term & Expiration Planning Sheet is designed to help inventors, product developers, and researchers record:

• Patent number and patent type

• Relevant filing and grant dates

• Estimated expiration date

• Applicable maintenance-fee milestones

• Patent term adjustments, extensions, or disclaimers to investigate

• Official records used to verify the information

Use the worksheet as a planning aid while researching a patent. It does not calculate or certify a legally definitive expiration date, and it does not replace a review of the patent's official records.

Download the Patent Term & Expiration Planning Sheet (PDF)

What Happens When a Patent Expires?

When a U.S. patent expires, the exclusive rights provided by that patent generally end. Others may then be able to use the invention described by the expired patent without permission under that patent.

However, an expired patent does not automatically mean every version of a product is free to make, use, or sell.

Other active patents may cover related features or improvements. Products may also be subject to separate intellectual property rights, regulatory requirements, or other legal restrictions.

Before commercializing a product based on an expired patent, it is important to consider whether other active patents or restrictions may apply.

Frequently Asked Questions

Do all patents last 20 years?

No. Utility and plant patents generally have a term ending 20 years from the applicable filing date, subject to relevant rules and limitations. Modern U.S. design patents generally last 15 years from the grant date, while design patents from applications filed before May 13, 2015, generally have a 14-year term from grant.

Does a patent last 20 years after it is approved?

Generally, no. For most modern U.S. utility and plant patents, the ordinary term is measured from the applicable filing date, not 20 years after grant. Design patent terms are measured from the grant date.

Do I have to pay to keep a patent active?

Utility patent owners generally must pay maintenance fees at specified intervals after issuance. Design and plant patents do not require maintenance fees.

Can an expired patent be renewed?

A patent generally cannot be renewed simply to extend its ordinary term. In certain circumstances, a lapsed patent may qualify for reinstatement, or the applicable term may be affected by a statutory adjustment or extension. The rules depend on the particular circumstances.

Can I use an invention after its patent expires?

The expiration of a patent generally ends the exclusive rights provided by that patent. However, other active patents or legal restrictions may still apply to the product or invention.

Where can I check a patent's expiration date?

Start with the USPTO's Patent Public Search and review the patent's official records. The USPTO Patent Term Calculator can help estimate the term, but related applications, adjustments, extensions, disclaimers, and maintenance-fee history may affect the result.

Final Takeaway

How long a patent lasts depends primarily on its type and the applicable filing or grant dates. Most modern U.S. utility and plant patents have ordinary terms ending 20 years from the applicable filing date, while modern design patents generally last 15 years from the grant date.

The actual expiration date may differ because of related applications, patent term adjustments or extensions, terminal disclaimers, maintenance fees, and other legal circumstances.

If you are researching an existing patent, use official USPTO records to verify its status and estimated expiration date. If you are planning to file for patent protection, understanding patent duration can help you make better-informed decisions about development, commercialization, and licensing.

For more help navigating the patent process, explore our guides to Patent Basics, How to File a Patent, and Patent Costs Explained.

This article provides general educational information about U.S. patent terms and is not legal advice. Patent terms and expiration dates depend on the applicable law and the details of each patent.

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