This article discusses patent subject matter eligibility.

1. Summary

Some of the requirements for an invention to be eligible for a patent include:

- Must fall into one of four categories: process, machine, manufacture, or composition of matter.

- Must be useful. Landfill is not useful.

- Only one patent per invention. Multiple patents cannot be obtained for the same invention. A product may have multiple inventions. An improvement to an invention may be patented.

- Must be new. Novelty issues are typically handled under 35 U.S.C. 102.

- Cannot be abstract ideas, natural phenomena, or laws of nature. Courts have found these to not be patent eligible.

- Meet requirements in Manual of Patent Examining Procedure (MPEP).

2. Process, Machine, Manufacture, or Composition of Matter

35 U.S.C. 101 states:

Whoever 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 therefor, subject to the conditions and requirements of this title. (emphasis added)

To be eligible for a patent, the invention must fall into one of four categories: process, machine, manufacture, or composition of matter.

For how software can be described as a process, machine, and manufacture see Is Software Patentable.

3. Useful

35 U.S.C. 101 states:

Whoever 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 therefor, subject to the conditions and requirements of this title. (emphasis added)

To be eligible for a patent, the invention must be useful. For example, courts have found landfill to not be useful and thus not patent eligible.

4. A Single Patent per Invention

35 U.S.C. 101 states:

Whoever 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 therefor, subject to the conditions and requirements of this title. (emphasis added)

Only a single patent may be granted for an invention. An improvement to the invention is patent eligible.

A product may contain multiple inventions. For example, a mobile phone may have patents on facial recognition, text message summarization, text selection on the screen, cellular communication protocol, and the battery since each of these is an independent invention.

5. New

35 U.S.C. 101 states:

Whoever 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 therefor, subject to the conditions and requirements of this title. (emphasis added)

Although 35 U.S.C. 101 requires the invention to be new, novelty issues are usually handled under 35 U.S.C. 102.

6. Abstract Ideas, Natural Phenomena, and Laws of Nature

Courts have found abstract ideas, natural phenomena, and laws of nature to be not patent eligible. Some courts have found certain patents to be abstract ideas which caused the patent to be lost. Some software and medical diagnostics patents have been lost due to subject matter eligibility issues. As courts have taken differing positions on subject matter eligibility, subject matter eligibility is an unsettled issue.

The Alice/Mayo framework is used to determine if an invention is eligible for a patent. When the U.S. Patent and Trademark Office (USPTO) rejects claims because of subject matter eligibility, these rejections are often called Alice 101 rejections. See MPEP Patent Subject Matter Eligibility for the USPTO guidance.

7. Other Requirements for Obtaining a Patent

There are additional requirements to obtain a patent in addition to subject matter eligibility (35 U.S.C. 101). These include:

- New - 35 U.S.C. 102

- Non-obvious - 35 U.S.C. 103

- certain parts of 35 U.S.C. 112

- USPTO requirements MPEP. The MPEP includes the USPTO interpretation of 35 U.S.C. 101, 102, 103, and 112. The courts are not bound by the USPTO interpretations and may decide an issue differently than the USPTO.