What Is Patent Expiration?

As part of the how to patent an idea process, in the United States, patents expire within 14-20 years from the filing date, depending on what you've patented and when. Once this happens, your idea passes into the public domain.

Once a patent expires, an average of 17.2 competing companies hit the market with similar products. While the public may view this as good because it means the invention is available to everyone, it often results in a loss of income for the company that originally held the patent.

To see if a patent is still in force, use the United States Patent and Trademark Office (USPTO) website and look up the patent. You'll see its image in a PDF format. The USPTO does have a Patent Term Estimator spreadsheet, which helps you estimate a patent's term and expiration date with Microsoft Excel. You can also see patent information through Google Patents or the European Patent Office's espacenet system. Lexis or Westlaw or BNA USPQ databases will also provide expiration information. However, there is a fee associated and access is required.  Through their systems you would search court cases for the patent number.  If th patent number is involved in a case, you'll use that case citation to locate it through the Public Access to Court Electronic Records System, also called PACER.

Details That Affect Patent Expiration

If you hold a patent, you need to know how much time you have to work on your product and have it on the market. Meanwhile, someone else might be waiting for the idea to enter the public domain. Various details affect how long your patent will be good for.

Patent Research Procedure

Before researching a patent for its expiration date, check the patent number and type. Any original-issue Utility Patents (not Design Patents starting with "D" or "Des"), Plant Patents, or Reissues of Utility Patents with patent numbers of 4,999,999 or less expired on or before August 31, 2010, so you can be confident they're already in the public domain.

If you're unable to use this shortcut for reviewing patent expiration dates and you don't yet have a printed copy, call up the patent in question on the USPTO patent database, Google Patents, or the espacenet system. You'll need to review how to read a patent.

  • Utility and Plant Patents filed after June 8, 1995 have a 20-year patent term from those filing dates.
  • Utility and Plant Patents that were pending on June 8, 1995 or were issued on or after June 7, 1978 and hadn't expired before June 8, 1995 have patent terms measured by 17 years from the issue date or 20 years from the US filing date.
  • Utility and Plant Patents issued before June 7, 1978 have all expired, having a 17-year term from the date of issue.
  • Design Patents granted before May 13, 2015 have a 14-year term from the date of issue.
  • Design Patents filed on or after May 13, 2015 have a 15-year term from the date of issue.

Terminal Disclaimers

Certain patent terms may be tied to other patents. When this happens, a patent may have fewer patented years based on an earlier-issued patent. This is a result of filing two separate applications on the same invention and is called a "terminal disclaimer." Terminal disclaimers may be marked with an asterisk or add text in the "related application" data on the patent database.

Using the USPTO Public PAIR system can help you locate terminal disclaimer files. Look for the Image File Wrapper or, if there isn't one, the "Continuity" tab in the PAIR system. Call up the patent and review its procedure to find common expirations for all patents the invention is associated with.

Terminal Disclaimers are based on the following:

  • Full Statutory Term: generally includes the patent term extension.
  • Specific Dates: disclaims a specific term past a stated date without references the term of an associated patent.
  • Both a Term and Date: often found in older disclaimers.

Terminal disclaimers for patents filed after June 1995 will have little effect since associated patents will have the same expiration date.

In the case of extended basic terms:

  • Patents filed on or after May 29, 2000 might have extended terms due to Patent Office delays. Extensions callled "patent term adjustments" and are automatically marked on the patent. Adjustments are based on a USPTO formula.
  • Patents issued between August 2009 and March 2010 contain miscalculated adjustments, opening up extensions. Any affected patent holders can fill out a Wyeth request form on the Public PAIR system.
  • Special cases include extreme government delays, which are very unusual and almost always associated with pharmaceuticals, food products, and medical procedures or devices due to Food and Drug Administration approval. These patents can have their terms extended by Congress.

Essentially, terminal disclaimers and extensions are often granted to patents affected by either a long FDA-approval process or USPTO delays. Any voluntary disclaimer or re-examination is attached to the patent image in the USPTO database unless in rare occasions when patents are withdrawn.

Maintenance fees on Utility Patents are due at 3.5, 7.5, and 11.5 years from the issue date. This is because U.S. patents expire at years 4, 8, or 12 if the fees are not received by the USPTO. Payment windows are open six months before the due date and close one year later. During the grace period after the due date, a surcharge goes into effect. If the proper maintenance fees are not paid in time, the patent expires.

Reasons to Research Rolling Patent Expirations

Rolling expiration dates are somewhat different and require careful research or patent search and analytic software. A rolling expiration date field on a patent allows you to find active patents coming up for renewal, which allows you to plan budgets. You can also find active patents in grace period to catch mistakes and even acquire patents. If you find expired patents still in their resurrection window, you can acquire previously expired patents.

When patents expire after the 4, 8, or 12-year maintenance periods, they can only be reinstated with a surcharge and legitimate excuse. While patents are occasionally reinstated, they're often allowed to expire in what are known as expiration tranches, which comes from the French word for "slice." These are called E1, E2, and E3, and the reinstatement fees for each tranche get subsequently higher.

Using software like Acclaim IP or Innography can help you break down each tranche within specific search parameters. In the case of Innography, you can calculate patent expiration dates worldwide, reviewing such factors as:

  • The 1995 Rule
  • Term Adjustments
  • Legal Status Events
  • Continuity Priorities
  • Abandonments
  • Maintenance Activities
  • Terminal Disclaimers

What Could Happen After a Patent Expiration?

The point at which the patent protection goes away is known as the "patent cliff." When a patent reaches this cliff, the effects depend on the industry. For instance, in the pharmaceutical industry, an expired patent means the addition of generic medications. This results in more competition, making it easier for customers to afford medications.

For companies holding invention patents, they may need to lower their market prices on products reaching the patent cliff. This is because competing companies will have access to the patent and can produce their own products. This leaves the original company with a large amount of unsold stock and often leads to profit streams drying up.

On the flip side, companies may increase advertising leading up to the patent cliff to draw from their loyal customer base who demand quality. They may take a pre-expiration strategy and release their own generic form of a product before the patent expiration.

Additionally, cutting production as the patent cliff approaches is often a smart move. It's expensive to store stock, and in the case of food or medications, some products have a shelf life. Nearing the end of a product's patent life, decreasing production can help make sure there isn't a large amount of stock left that can't be sold.When facing the cliff, no company wants to be left with stock on hand that they will never see a return from. 

Another pre-expiration strategy, called "layering innovations," is when the original patent holder is given more patents for improvements to the original patent. By making an upgraded version, the patent is extended and the company continues to enjoy its monopoly.

Line extension is another option. This strategy calls for finding new ways to use a patented idea. For instance, pharmaceutical companies can find new diseases that can be treated by a previously patented drug. Patents must meet specific criteria of being useful and novel, but they cannot be so obvious that just anyone can think of them.

Additional Line of Protection

Of course, you don't have to leave your expiring patent to the mercy of the USPTO's rules. As long as you keep part of your invention a secret, no one else can ever copy it. These fine details only the inventor knows are known as "trade secrets." In fact, major brands such as Coca Cola are known for keeping their recipes a secret, helping preserve the product's taste and keep customers from switching to a generic version.

So, why provide the USPTO with every tiny detail of your creation? In doing so you leave yourself and your invention completely vulnerable. Of course they require that you provide them with the process when you initially obtain the patent. Many inventors, like a chef, has special ingredients or a special formula. By holding back a key ingredient or two, no one else can ever truly copy your invention.

What Could Happen When a Patent Is Infringed Before the Expiration?

Patent infringement is a situation in which a competitor violates the patent protection without permission. When this occurs, the patent holder can ask for an injunction from the courts that stops the competitor from profiting. The patent holder can also claim damages.

While patent infringement typically isn't an issue within the U.S., it is a major source of international conflict. Asian companies, for instance, cost U.S. pharmaceutical companies hundreds of millions of dollars each year from patent infringements.

A high-profile patent issue affecting individuals is found in Monsanto and the company's Roundup Ready soybeans. Launched in 1996, these soybeans were a creation of science and agricultural technology. This resulted in larger soybean yields and Roundup-resistant traits. Due to the patent, however, farmers had to make sure they could legally save the seeds for replanting. Unlike most patent expirations, the variety of patents Monsanto holds will be valid long after the Roundup Ready trait patent expires. Farmers cannot save seeds from patented Monsanto soybeans beyond 2015, and these trait patents are not expected to expire until the end of the 2020s.

Frequently Asked Questions

  • How long does a patent provide protection?

In the United States, patents provide protection for 14-20 years from the original date of application filing. Other countries have specific patent processes ranging from 10-20 years.

  • Where can I search for patent information?

Search for patents on the United States Patent and Trademark Office website, Google Patent Search, the espacenet system, or analytical software.

Missing your patent maintenance fees can result in costly surcharges and other fees. The worst-case scenario is losing your patent altogether.

  • What do I do when my patent is nearing its expiration date?

Depending on the nature of the patent, you could utilize pre-expiration strategies like pre-emptively launching your own generic product to extend the patent or retain financial success following the expiration.

  • Can the law declare a patent invalid?

Yes. When a patent is deemed invalid by a court, it becomes unenforceable and the patent holder loses all protections.

You can look up patent numbers and their reported court cases in paid databases such as Westlaw, Lexis, or BNA USPQ. Once you know the case citation, you can then look it up in the PACER system. In addition, you can try performing a Google search on a certain patent number to see if it's associated with any court case.

If you need help with an expiring patent, you can post your question on UpCounsel's marketplace. UpCounsel accepts only the top 5 percent of lawyers to its site. Lawyers on UpCounsel come from law schools such as Harvard Law and Yale Law and average 14 years of legal experience, including work with or on behalf of companies like Google, Menlo Ventures, and Airbnb