How to Tell If a Patent Is Still Active

Knowing whether a patent is currently active sounds like a simple question. It's not. A patent can be expired by the calendar, lapsed for nonpayment, abandoned during prosecution, invalidated by a court, or disclaimed. Each has different implications.

Here's how to check status systematically.

Step 1: Confirm it actually granted

Published patent applications (numbers like US 2019/0123456 A1) are not granted patents. If you found a publication number rather than a patent number, check whether the application proceeded to grant.

In Patent Center (patentcenter.uspto.gov), search the application number. The status field will show whether the application is pending, issued as a patent, abandoned, or otherwise resolved.

An abandoned application has no patent rights. The applicant gave up, or failed to respond to office actions, or paid fees late beyond the grace period.

Step 2: Calculate the expiration date

For a granted patent, calculate the expiration date:

• Utility patents filed after June 7, 1995: 20 years from earliest effective filing date, plus PTA, minus any terminal disclaimer cutoff
• Design patents granted after May 12, 2015: 15 years from grant
• Design patents granted before May 13, 2015: 14 years from grant
• Pre-1995 utility patents: greater of 17 years from grant or 20 years from filing

If today's date is past the calculated expiration, the patent is expired.

The Patent Sunset calculator handles this calculation automatically. Enter the patent number and it computes the expiration date including PTA, PTE and terminal disclaimer data from the USPTO's Open Data Portal.

Step 3: Check maintenance fee status for utility patents

Even if the calendar-based expiration date is in the future, a utility patent may have expired for nonpayment of maintenance fees.

In Patent Center, pull up the patent and look at the Fee Status or Bibliographic Data tab. Look for "expired" or "abandoned" status in the maintenance fee section.

Maintenance fees are due at 3.5, 7.5 and 11.5 years after grant. Missing one, plus the 6-month grace period, causes the patent to expire before its full 20-year term.

Step 4: Check for terminal disclaimers

If the prosecution history includes a terminal disclaimer, the patent's effective expiration date may be earlier than the 20-year calculation suggests.

In Patent Center, look at the Documents tab in the prosecution history. Filter for "Terminal Disclaimer" documents. If you find one, identify which patent it was disclaimed over and check that patent's expiration date.

Step 5: Check for reexamination, IPR, or invalidation

A patent can be challenged after grant through several mechanisms:

• Inter partes review (IPR) at the USPTO's Patent Trial and Appeal Board
• Post-grant review (PGR)
• Ex parte reexamination
• Court invalidation in litigation

If a patent has been through one of these processes and claims were cancelled or the patent was found invalid, those claims are unenforceable even if the patent appears "active" by dates.

Patent Center shows reexamination and trial proceedings in the prosecution history and related proceedings sections.

Step 6: Check the assignment and ownership

A patent can be sold, licensed exclusively, or subject to ownership disputes. If you're tracking whether a patent can be enforced against you specifically, who owns it matters.

The USPTO Assignment Database (assignments.uspto.gov) records patent assignments and transfers. If the patent has been assigned, the current assignee is the party with enforcement rights.

What "active" means for different purposes

If you're assessing whether a patent can be enforced against your product, all of the above factors matter.

If you're asking whether a patent is still in force in the patent system's records (even if it might not be enforceable due to invalidity), that's a simpler question answered by steps 1-4.

If you're doing competitive intelligence and want to know when a technology becomes freely available, you need the expiration date from steps 1-4 and an assessment of whether claims are meaningful in step 5.

The depth of the analysis depends on the stakes involved.