Data report · 2026
The state of expiring patents
Every year, landmark inventions lose their patent protection and become free for anyone to build on, manufacture, and improve. Here's what entered — and is entering — the public domain, drawn from the 838 most consequential US patents we track.
landmark US patents already in the public domain — free to use without a license
of the 838 landmark patents we track have entered the public domain
more enter the public domain during 2026, including foundational biotech and social-media inventions
Why it matters
Expiry is when a patent gives back
A US utility patent lasts 20 years from its filing date. When it expires, the invention enters the public domain: anyone can make, use, sell, and build on it without permission or a license. Expiry is the bargain at the heart of the patent system — a temporary monopoly in exchange for permanently teaching the world how something works. The patents reaching that point now were filed around the turn of the millennium, which means foundational internet, mobile, and biotech inventions are coming free.
Entering the public domain in 2026
The landmark patents expiring this year
Ranked by how often later patents cite them — a proxy for influence. Each links to a plain-English explanation of what it covers.
The long arc
When today's public-domain patents were granted
The 271 landmark patents now in the public domain, by the decade they were granted. The wave crests in the late 20th century — the inventions that defined modern computing and medicine are now free.
Methodology & data
Figures are drawn from PatentBrief's curated corpus of 838 landmark US patents — not the full US patent system — which is what makes them about consequential inventions rather than averages. A patent is counted as public domain when its status is expired or its expiration date (20 years from filing) has passed. Counts update daily. The underlying data is open: public-domain.json, patents.json, and the developer endpoints.