What is the doctrine of equivalents in patent law?

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Source: FAQ (MPEP-Based) BlueIron Update: 2024-09-29 9 Rules 5 Related FAQs This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice. The doctrine of equivalents is a legal principle that arises in the context of patent infringement actions. As stated in MPEP 2186 : “If an accused product or process does not literally infringe a patented invention, the accused product or process may be found to infringe under the doctrine of equivalents.” This doctrine allows for a finding of infringement even when the accused product or process doesn’t literally meet every element of a patent claim, but is substantially equivalent. Related Rules from the Manual of Patent Examining Procedure 9 rules Collapse Infringement Under Doctrine of Equivalents Must Match Function, Way, and Result MPEP 2186 Infringement by Equivalent Elements MPEP 2186 Permitted Infringement by Equivalent Elements MPEP 2186 Means-Plus-Function Claims Must Be Equivalent to Specified Means MPEP 2186 Required Equivalents Not to Influence Means-Plus-Function Determination MPEP 2186 Recommended Equivalence Determination for Infringement MPEP 2186 Infringement by Equivalent Elements MPEP 2186 Means-Plus-Function Claims Must Be Equivalent to Specified Means MPEP 2186 Role of Elements in Determining Equivalence MPEP 2186 Other Related FAQs 5 FAQs Collapse How does 35 U.S.C. 112(f) relate to the doctrine of equivalents? How is the doctrine of equivalents applied in patent infringement cases? How does the doctrine of equivalents affect patent examination? What is the function-way-result test in the doctrine of equivalents? How does an examiner handle new matter in a patent application?