How Long Is a US Patent Good for?

Rich Goldstein

Founder & Principal Patent Attorney

Are you wondering how long is a US patent good for?  A patent’s term depends on the type of patent, but most patents are good for 20 years. The calculation depends on many factors, including the type of patent, whether regulatory approval is needed, and how long the United States Patent Office takes to approve the patent. 

The Patent Term Depends on the Patent Type

How long does a patent last? The first thing to consider is what type of patent. Different patent types protect different intellectual property and last different lengths of time. There are two main patent types issued in the United States to protect intellectual property:

  1. Utility patents
  2. Design patents
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How Long Is a Utility Patent Good for?

Utility patents are good for a period of 20 years from the filing date the nonprovisional patent application for the invention. This patent term of 20 years from the date can be subject to adjustments and extensions, which are explained in more detail below.

Utility patents are the main types of patents that are issued. These patents protect the intellectual property of novel products, machines, processes, or compositions of matter that are considered useful. It protects the way something is used and works. 

How Long Are Design Patents Good For?

Design patents are good for a period of 15 years from the date of issuance of a patent application for the design invention. This 15-year patent term is generally not subject to adjustments and extensions like a utility application could be.

Design patents protect the intellectual property of the shape, appearance, or other attributes of how something looks. You can apply for both utility and design patents for the same invention if your invention has both a useful application and the design features you want to protect.

How Long Is an International Patent Good for?

When people go to patent a product, they often apply for a patent internationally.  There is no “international patent” per se, but the Patent Cooperation Treaty provides a unified procedure for filing patent applications “hold” or establish priority patent rights in all countries participating in the treaty. An international patent application under the Patent Cooperation Treaty will give you up to 30 months to file “national” applications in the individual countries.  

The patent office and law of each individual country will determine the term of your patent in that country. However, most countries have a patent term of 20 years from the date of filing.

How Long Was a Patent Good for Historically?

The 20-year patent term and 15-year patent term now applied were not always the standard practice in the United States for intellectual property. Historically, the Patent Office could choose the patent’s term period on an individual basis, with the patent term never exceeding 14 years from the date of filing. Then in 1861, the patent office changed it to a patent term of 17 years.

Moreover, under the old patent law, the patent term began on the date the patent was issued by the Patent Office rather than the filing date, as it is today for utility patents (and as it still is for design patents).

In 1995, the United States patent office changed its patent laws to come in line with the patent term laws applicable internationally. 20 years from filing is now the standard patent term that is generally applied internationally. US patent laws were also changed at this time to move to a first-to-file system rather than a first-to-invent system, also coming in line with international patent laws.

Patent Application Filing Dates Affect How Long a Patent Is Good for

The date that you file your patent application has a direct effect on how long the patent will be good for. This date is also known as your “priority date.” The type of patent application you file with the Patent Office will also affect the term of your patent.

Man holding a stamp

How Long Does a Patent Last When Filed Under a Provisional Patent Application?

A provisional patent application is an informal patent application that preserves your filing date with the United States Patent Office without requiring you to file a more formal application. A provisional patent application expires after one year. 

People often like to file a provisional patent application to preserve an earlier filing date in the first-to-file patent right environment.  This gives themselves additional time to perfect their invention before filing the more formal, nonprovisional patent application. 

How long does a patent last after filing a provisional patent application? Interestingly, the date you file your provisional patent application is not considered your “filing date” for purposes of calculating either a 20-year utility patent term or a 14-year design patent term. If you file a provisional patent application first, you can think of it as a “bonus year” in that you may actually end up with 21 years of protection.

How Long Does a Patent Last When Filed Under a Nonprovisional Patent Application?

 A nonprovisional patent application is the formal patent application you submit under oath or declaration to the United States Patent Office. This application’s filing date is the “filing date” used to calculate the patent’s term.  Therefore, a patent will generally expire 20 years after the filing date.

How Long Does a Patent Last When Filed Under a Continuing Patent Application?

A continuing patent application (or continuation-in-part) is used when you seek to claim additional subject matter or made improvements or add-ons to a patent that you have already submitted an application for. A patent granted on a continuing patent application preserves this priority and will expire 20 years from the date you filed the first nonprovisional application for the original, underlying patent. 

This rule prevents inventors from extending their patent monopoly.  Because your continuing patent application is simply building off of your original patent application and associated intellectual property, it makes sense to apply that same term to any improvements that might have been made to its original form. 

Otherwise, people could circumvent the core principles of the patent system and obtain a seemingly never-ending patent by continuing to make minor tweaks to their original invention.

This rule also originated when the patent term was changed in 1995.  In part, the rule was created to stop “submarine’” patents, where an inventor would file a chain of patent applications over a period of decades. When each application was approved, the inventor would prevent it from issuing so that the application would remain secret.  Then after the public had been using the invention for decades, the inventor would allow the patent to issue, taking everyone by surprise.  Then, the investor would have a full 17-year patent term and be able to suddenly control what was already a mature market for the invention!

US patent files being tracked for how long it will last for

How to Calculate a Patent Term by Application Type

An example will help illustrate how a patent’s application dates affect how long it is good for.  If you:

  • Filed a provisional patent application on January 1, 2000;
  • Filed a nonprovisional patent application on January 1, 2001; 
  • Received patent approval on May 30, 2002;

then your patent would last until January 1, 2021. 

The US Patent Office has developed a downloadable patent term calculator to help you estimate how long your patent will be good for. 

The Importance of a Patent’s Term

Understanding the term of your patent is important because it tells you how long a patent owner keeps the intellectual property and patent rights to your patented invention. 

According to the Patent Office, patent rights give the patent owner the right to exclude others from making, using, selling, or importing the invention. Specifically, 35 U.S.C. § 154 states:

Every patent shall contain a short title of the invention and a grant to the patentee, his heirs or assigns, of the right to exclude others from making, using, offering for sale, or selling the invention throughout the United States or importing the invention into the United States, and, if the invention is a process, of the right to exclude others from using, offering for sale or selling throughout the United States, or importing into the United States, products made by that process, referring to the specification for the particulars thereof.

In other words, in order to make, use, or sell a patented invention, other people will have to go through the patent owner and get their express permission. This means the patent owner controls the market for that invention and is able to reap the benefits of their ingenuity.

Patents Cannot Be Renewed After They Expire

Generally, a patent can’t be renewed after the patent expiration. After a 20-year or 15-year term of a patent has expired, the patent cannot be renewed. However, if the patent lapsed prematurely a different reason, the patent owner may be able to reinstate it. 

If you have a utility patent, patent holders are required to pay maintenance fees in certain increments during the lifecycle of your patent. If these maintenance fees are not paid within their proper time periods, the patent will expire prematurely. Under the right circumstances, you can still reinstate this patent for the remainder of its term, as long as you pay additional petition fees to reinstate it on top of the maintenance fees. 

How Patent Term Adjustments Affect How Long Your Patent Is Good for

The US Patent Office applies Patent Term Adjustments to account for delays that may take place while your patent is pending.  Remember that your patent expiration date is dependent on the patent filing date, not the patent’s approval date.

You may experience delays between the patent filing date and the date your patent is issued, i.e., during the patent prosecution phase. The Patent Office may take a while to review your initial application or may take a long time reviewing any changes you make to your application after the Patent Office has issued you an Office Action. 

To combat this, when there has been an unfair delay at the Patent Office, they automatically apply Patent Term Adjustments when it approves your patent. 

Categories of Patent Term Adjustments

There are three categories that will qualify patent owners for a patent term adjustment.  Each category provides varying levels of time that are added on to your patent’s term length to adjust for the Patent Office’s delays.

Man about to sign a document

Category A

Category A Patent Term Adjustments are applied if the Patent Office:

  1. fails to act within 14 months after the application filing date;
  2. fails to respond to an application Reply or Patent Trial and Appeal Board decision within 4 months; or 
  3. fails to issue a patent within 4 months after the issue fee has been paid.

Category B

Category B Patent Term Adjustments are applied if the Patent Office:

  1. fails to issue a patent within 3 years of the filing date.

Category C

Category C Patent Term Adjustments are applied if the Patent Office:

  1. Has any type of delay due to derivation proceedings, secrecy orders, or appeals. 

Applicant Delays 

Delays by the applicant will also impact how the Patent Term Adjustment is calculated.  According to 35 U.S.C. § 154(b)(2)(c), any applicable Patent Term Adjustment will be reduced by the number of days an applicant “failed to engage in reasonable efforts to conclude prosecution … of an application.”

This means it’s important for patent owners to respond promptly and diligently to any requests or inquiries by the Patent Office during the patent prosecution process.

Patent Term Adjustment Calculation

If any of the circumstances within the above three categories apply to your patent prosecution, your patent is eligible for Patent Term Adjustment. This will be calculated by applying the number of days your application was delayed by the Patent Office to your patent’s term.  

If any of the delays overlap between the different categories, the overlapping days are not double-counted in the total.  Moreover, any days that can be attributed to applicant delays are subtracted from the Patent Office delays. 

While the Patent Office automatically calculates and applies this number to your patent, it’s a good idea to check with a patent attorney to make sure you received all applicable time extensions. 

How Patent Term Extension Affects How Long Your Patent Is Good for

Another way to extend the life of your patent is through Patent Term Extension. Patent Term Extension extends the term of a patent that claims a product which requires regulatory approval prior to being sold or requires a specific method of using or manufacturing the product. 

Patent Term Extension most commonly applies to pharmaceuticals, food additives, and medical devices that are regulated by the Food and Drug Administration. Because these products can often take a long time to gain approval by the applicable regulating agency, the Patent Office may extend the patent term extension to account for these regulatory delays.

You must apply for Patent Term Extension, and you must apply for it within 60 days of the regulatory approval of the product. 

How Patent Term Extension Is Calculated

The Patent Office works in tandem with the applicable regulating agency to decide whether or not to apply Patent Term Extension and to determine the associated extension length. The patent term can be extended by one-half the time of the product’s testing phase, and the full time of the product’s review phase with the applicable agency. 

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