The simple answer is, not all ideas are patent-eligible.
35 USC Section 101 states,”[w]hoever invents or discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof, may obtain a patent … .”
Thus, to procure a patent, an idea should fall into one of the statutory defined categories — (i) a process, (ii) machine, (iii) manufacture, or (iv) composition of matter.
Machine or Transformation Test
A process, or also known as a business method, that is either be tied to a specific machine or transform physical matter is generally considered patent eligible. This is called the machine or transformation test. Please note, while this is not the sole test to determine patent eligibility of a process, in most cases, this remains the test followed by the USPTO, and challenging this assertion will be an uphill battle (although outliers do exist).
1. Actions performed by a person
Generally actions performed by a person do not pass the machine or transformation test. However, if the actions are performed by an intermediary machine (for the person), then the process will pass the machine or transformation test.
2. Medical Procedures
While medical procedures are patentable, per se, they are not enforceable for the purposes of awarding damages, based on medical procedure exception of 35 USC Section 287 (c). However, if the patented procedure requires a process (passing the machine or transformation test), machine, manufacture or composition of matter to implement the procedure, then the medical procedure is enforceable.
3. Tasks that can only be performed by a computer
Since a computer, by definition, is a machine, software programs or tasks performed by a computer, are processes that will pass the machine or transformation test as long as those tasks cannot be performed without a computer (more on this follows below).
4. Tasks that are ordinarily performed by humans, but can be performed by computers as well
Tasks, like escrow systems, have been performed by humans for at least hundreds, if not thousands of years. And prior to the Alice case, tasks performed by humans, and that could also be performed by computers, were considered patentable. Thus, pre-Alice, while an escrow system performed by a person was considered abstract (failed the machine or transformation test), the same process, when performed by a computer was patent eligible. However, the Supreme Court in Alice stated that simply implementing an, otherwise, abstract idea on a computer was not sufficient to make the patent ineligible matter eligible. Thus, now computer software programs need to have a concrete implementation to provide a showing that the implementation is not one that can be performed without a computer. For more information on this, please read our post on the Alice case.