Patents filed after June 8, 1995 last for a period of 20 years from the date the application was filed. Patents filed before June 8, 1995 have whichever is the greatest of a term of 17 years from the date the application was granted or 20 years from the date the application was filed.

A patent duration also depends on what kind of patent is being filed. The validity of patents is as follows:

  • Utility Patent: 20 years from the date of filing if filed prior to June 8, 1995 (or 17 years from the date the patent is issued, whichever is longer)
  • Utility Patent: 20 years from the date of filing if filed after June 8, 1995
  • Design Patent 14 years from the date of issue for design patents
  • Plant Patents: 17 years from the date of issue

Do Patents Ever Expire Early?

Patents can and sometimes do expire early. Some of the common ways that the duration of a patent term is cut short are:

  • The patent is found to be invalid
  • The inventor fails to pay maintenance fees

Once the patent expires, either because the time limit expired or failure to pay the required fees, the patent goes into the public domain and can be used, sold, or imported by anyone. The patent owner does not have rights over the patent after it expires, but may bring infringement action or enforcements actions if the patent was infringed during the time when the patent was not expired and was valid.

What Could Make My Patent Invalid?

A patent can be deemed invalid for a number of reasons. Usually, a patent will be found to be invalid during infringement cases where an accused infringer defends himself by claiming your patent is invalid. Some of the common reasons patents are found to be invalid are:

  • The invention was not actually patentable – if someone can bring evidence that your invention lacked the requisite novelty, utility, or non-obviousness required for a patent, the USPTO can declare your patent invalid.
  • You obtained the patent fraudulently – even if your invention was patentable, if someone can show that you got your patent by deceiving the USPTO, your patent can be declared invalid.
  • You used your patent to commit illegal acts – if you use your patent to engage in illegal conduct, the USPTO can declare your patent invalid.

What Are Maintenance Fees and When Do I Have to Pay Them?

Maintenance fees must be paid to the USPTO to keep the patent in force. Maintenance fees are due 3 ½ , 7 ½, and 11 ½ years after the patent has been granted. However, if you miss these deadlines, you have a 6 month grace period to pay the maintenance fee along with a penalty surcharge to keep your patent in force. If you fail to pay the maintenance fees, your patent will expire.

Can I Extend the Duration of My Patent?

Under certain circumstances, you can extend the duration of your patent. Generally, if the USPTO or another government organization has deprived you of any of the enjoyment of the rights granted to you by the patent, you can get an extension. However, no extension will exceed five years. Some of the common circumstances resulting in the extension of a patent occur when:

  • The application is initially denied and you win on appeal.
  • The USPTO takes a lot of time trying to decide if your invention infringes on another patent, and then decides it doesn’t infringe.
  • You invented a drug, medical device, food additive, or color additive and although you have a patent, you have to wait for the FDA to approve it before you can put it to commercial use. The USPTO enacted the Patent Term Restoration Program to deal with this very problem. The PTR Program restores up to 5 years from the time lost waiting for FDA approval.

How Can I Determine If My Patent Is Still In Force?

To determine whether a patent is still in force or whether the patent has expired, you will need to access the USTPO website and access the patent database. The patent website will allow you to access your patent information and determine whether the patent has been expired and when the patent will actually expire.

Do I Need a Patent Attorney?

If you have questions about the duration of your patent, you may want to consult a patent attorney. An experienced patent lawyer or intellectual property lawyer can explain the rules governing the length of your patent term and can help you ensure that your invention will be protected for as long as possible.