Guide · §101 eligibility
Why so many software patents die at “eligible.”
Before noveltynoveltyThe requirement that an invention be different from anything publicly known before its priority date.Read more → or non-obviousnessnon-obviousnessThe requirement that an invention not be an obvious combination of existing prior art to someone skilled in the field.Read more → even matter, a claimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → has to be the kind of thing patents cover at all. Section 101 says you can't patent an abstractabstractA short summary at the front of the patent describing the invention. Not legally binding.Read more → idea — and the Supreme Court's Alice test is where a huge share of software and business-method patents quietly die. Here's how it works, and how to survive it.
The three exceptions
Four categories are eligible — minus three exceptions.
Section 101 says a patent may be granted for any new and useful process, machine, manufacture, or composition of matter. Courts have carved out three judicial exceptions that fall outside it, no matter how clever:
Abstract ideas
Fundamental economic practices, methods of organizing human activity, and mathematical concepts. This is where most software and business-method claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more → fall.
Laws of nature
Natural principles and relationships — you can't patent gravity, E=mc², or a naturally occurring correlation between two things.
Natural phenomena
Products of nature as they exist naturally — a gene as it appears in the body, a mineral, a wild plant. Isolating it alone usually isn't enough.
The Alice / Mayo test
Two steps decide it.
Is the claim directed to an exception?
Ask whether the claimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more →, read as a whole, is really about an abstractabstractA short summary at the front of the patent describing the invention. Not legally binding.Read more → idea, law of nature, or natural phenomenon. If it isn't — a genuine machine or manufacturing process — it's eligible and the analysis stops here.
Is there an “inventive concept” — significantly more?
If it is directed to an exception, look for something extra that transforms it into a patent-eligible application — a specific, inventive technical implementation. Reciting the idea and saying 'apply it' or 'do it on a computer' is not enough. This is the step that fails most claimsclaimsThe numbered statements at the end of a patent that legally define what the inventor owns.Read more →.
The cases that set it: In Mayo v. Prometheus (2012) the Court rejected a claimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → that paired a natural correlation with routine steps. In Alice v. CLS Bank (2014) it rejected computer-implemented escrow as an abstractabstractA short summary at the front of the patent describing the invention. Not legally binding.Read more → idea on a generic computer. Together they built the two-step test every examinerexaminerThe USPTO official who reviews a patent application and decides whether to grant it.Read more → now applies.
What survives, what dies
Rejected
Automating a known practice on a generic computer
“Do escrow / advertising / bookkeeping, but on a computer” is the classic Alice rejection.
Eligible
Improving how the computer itself works
A new data structure, memory scheme, or networking method that makes the machine faster or more efficient is eligible (e.g. Enfish).
Rejected
A result with no specific mechanism
Claiming the goal (“detect fraud”) rather than a particular technical way of achieving it reads as abstract.
Eligible
A concrete improvement to a technical field
A specific, non-generic process that solves a technical problem in a particular way can clear step two.
Check your idea
Eligibility is only the first of four gates.
Clear §101 and you still face noveltynoveltyThe requirement that an invention be different from anything publicly known before its priority date.Read more →, non-obviousnessnon-obviousnessThe requirement that an invention not be an obvious combination of existing prior art to someone skilled in the field.Read more →, and enablementenablement112 requirement: the patent must teach a skilled person to make and use the invention without undue experimentation. Broad claims can fail enablement.Read more →. Run your invention through all four in two minutes.
A plain-English overview, not legal advice. §101 law shifts with each new Federal Circuit decision — confirm current eligibility with a patent attorney. PatentBrief is not a law firm.