Patent expiry

Cross-referenced

Maintenance fees

Periodic fees that must be paid to the USPTO to keep a granted utility patent in force. For US utility patents, fees are due at 3.5 years, 7.5 years, and 11.5 years after grant. If a fee is missed, the patent expires. Many patents go abandoned not because the invention was worthless, but because the owner decided the cost of maintenance wasn't justified by the remaining commercial value.

Cross-referenced

Patent

A government-granted right that gives an inventor the exclusive right to prevent others from making, using, selling, or importing a patented invention within the country that granted the patent, for a limited time. A patent does not give the owner the right to practice the invention — only the right to exclude others. The US issues three types: utility, design, and plant patents.

Cross-referenced

Public domain

The status of an invention (or creative work) that is no longer — or never was — protected by any intellectual property rights, meaning anyone can use it freely. Patents enter the public domain after expiration (typically 20 years from filing for utility patents). Expired patents represent a vast, free library of technology available to all. Many foundational technologies — aspirin, the original CRISPR patents — have entered or are approaching the public domain.

Patent family

The set of related patents and applications that share a common priority claim — an original application plus its continuations, divisionals, and foreign counterparts. Members of a family typically share the same earliest filing (priority) date.

Post-grant review (PGR)

A USPTO proceeding to challenge a recently granted patent, within nine months of grant, on almost any ground of invalidity — including eligibility and written description. It is broader than inter partes review, which is narrower and becomes available later.

Patent citation

A reference connecting two patents: the earlier patents and publications a patent cites as prior art (backward citations), and the later patents that cite it in turn (forward citations). Citations map the lineage of an idea — what an invention built on, and what was later built on it. A 2010 patent cited by 200 later patents is, by that measure, a foundational piece of its field.