2104 Patentable Subject Matter [R-08.2012]
35 U.S.C. 101 Inventions patentable
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.
35 U.S.C. 101 has been interpreted as imposing three requirements.
First, whoever invents or discovers an eligible invention may obtain only ONE patent therefor. This requirement forms the basis for statutory double patenting rejections when two applications claim the same invention, i.e. claim identical subject matter. See MPEP § 804 for a full discussion of the prohibition against double patenting.
Second, a claimed invention must fall within one of the four eligible categories of invention, i.e., process, machine, manufacture, or composition of matter, as these categories have been interpreted by the courts. See MPEP § 2106 for a detailed discussion of the subject matter eligibility requirements and MPEP § 2105 for special considerations for living subject matter.
Third, a claimed invention must be useful or have a utility that is specific, substantial and credible. See MPEP § 2107 for a detailed discussion of the utility requirement.