Machine-or-transformation test

In United States patent law, the machine-or-transformation test is a test of patent eligibility under which a claim to a process qualifies for consideration if (1) the process is implemented by a particular machine in a non-conventional and non-trivial manner or (2) the process transforms an article from one state to another.

The origin of the test can be traced to the 1972 government's reply brief on the merits in the US Supreme Court case Gottschalk v. Benson:

"we submit that the cases follow such a rule [machine or transformation]—implicitly or explicitly—and that they cannot be rationalized otherwise."

The test was also mentioned in the 1970s patent-eligibility trilogy—Gottschalk v. Benson, Parker v. Flook, and Diamond v. Diehr.

The "machine-or-transformation test" was finally endorsed in 2008 by Federal Circuit in Bilski, while explicitly overruling its earlier “useful, tangible and concrete result” test adopted in 1998 in State Street Bank & Trust Co. v. Signature Financial Group, Inc. Numerous legal commentators praised the "machine-or-transformation" test for its simplicity, objectivity, reliability, and independence of the result from time and prior art availability. Judge Pauline Newman wrote a strong dissent arguing for a broader definition of patentable processes.

On appeal, in its 2010 decision in Bilski v. Kappos the US Supreme Court refused to endorse the "machine-or-transformation" test as the sole criterion for patentable subject matter, stating instead, that machine-or-transformation test "while useful, is not an exclusive test for determining the patentability of a process". Following Pauline Newman's dissent, the SCOTUS opined, that future cases might present fact patterns calling for a different rule from that applicable to past cases, and therefore the machine-or-transformation test was just a "clue" (i.e. it is neither a necessary nor sufficient test- see below) for patent-eligible subject matter.

In the wake of the 2010 Supreme Court's opinion in Bilski v. Kappos, rejecting machine-or-transformation as the sole test of patent eligibility, and confirming that it is only a "useful clue," it is now clear, that this test is only a way to measure whether the patent claim in issue preempts substantially all applications of the underlying idea or principle on which a patent is based—such preemption being a far more basic and general test of patent eligibility or ineligibility.