Pre-1995 Patents: Why the Expiration Rules Were Different
Patents filed before June 8, 1995 follow different expiration rules than modern patents. Understanding the old rules is still relevant for portfolios that include older patents.
·4 min read
Patent Blog
Practical guides on US patent expiration, patent term adjustment, extensions and maintenance fees.
How to Read a US Patent Number
US patent numbers follow specific formats that tell you the type of patent and roughly when it was filed or granted. Understanding the format helps you work with patent data more effectively.
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What Is a Utility Patent and How Long Does Protection Last?
Utility patents are the most common type in the US, covering functional inventions. Understanding what they protect and how long they last is the foundation of patent literacy.
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Can You Use an Invention After Its Patent Expires?
The short answer is yes, but the full picture involves checking all related patents, not just the one you found. Here's what to verify before assuming something is clear to use.
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How Patent Expiration Makes Generic Drugs Possible
Generic drugs aren't possible until the relevant patents expire. The path from brand-name exclusivity to generic competition involves patent law, FDA regulation and legal challenges.
·3 min read
Famous Patents That Have Expired
Some of the most transformative inventions in history are now in the public domain. Here's a look at notable patents that have expired and what their expiration meant.
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The Patent Cliff: Why Multiple Drug Patents Expire at the Same Time
When a major drug's patents expire and generics flood in, it's called a patent cliff. Understanding why these cliffs happen explains a lot about pharmaceutical industry dynamics.
·3 min read
When a Patent Expires, What Goes Into the Public Domain?
Patent expiration doesn't automatically mean anyone can do anything. Understanding what actually enters the public domain requires reading the claims, not just the title.
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Continuation Patents and Why Filing Date Matters More Than Grant Date
A continuation patent can be granted decades after its parent was filed but still expire at the same time. Understanding continuation chains is essential for accurate expiration tracking.
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How Drug and Device Patents Get Extra Time Under Section 156
The FDA regulatory review process can consume years of a patent's life. Section 156 allows patent owners to apply for an extension to partially compensate for that lost time.
·3 min read
What Is a Terminal Disclaimer and How Does It Affect Expiration?
A terminal disclaimer voluntarily shortens a patent's life to the term of a related patent. It can significantly change when a patent actually expires.
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Design Patent Expiration: How the Rules Differ
Design patents expire 15 years from grant, not 20 years from filing. Understanding these differences matters when tracking ornamental design protection.
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What Happens When a Patent's Maintenance Fees Go Unpaid?
Utility patents require maintenance fee payments at regular intervals after grant. Missing a payment can end a patent's life early, sometimes intentionally.
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What Is Patent Term Adjustment?
When the USPTO delays patent prosecution, applicants can get extra days added to their patent's term. Here's how PTA works and when it matters.
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How to Find a US Patent's Expiration Date
Finding a patent's expiration date isn't as simple as adding 20 years to the filing date. Here's what you actually need to check and how to do it quickly.
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How Long Does a US Patent Last?
US utility patents last 20 years from the filing date, but the real expiration depends on patent term adjustment, extensions and maintenance fees. Here's what affects it.
·3 min read