Patent Law Changes – is Best Mode Still Required?

The America Invents Act, signed by President Obama on September 16, 2011, has numerous provisions.Some of these provisions, by attempting to address one aspect of United States patent law, create confusion in other aspects.

For example, under existing U.S. patent Law (35 U.S.C. 112, first paragraph, in part), an inventor:

“… shall set forth the best mode contemplated by the inventor of carrying out his invention”.


The above part of existing U.S. patent law has not been expressly deleted by the America Invents Act.

However, the America Invents Act has expressly changed a section of U.S. patent law dealing with defenses in validity or infringement actions (35 U.S.C. 282) as follows:

“…the failure to disclose the best mode shall not be a basis on which any claim of a patent may be canceled or held invalid. ” (As amended by America Invents Act, 35 U.S.C. 282 (3)(A)

So is an inventor required to still set for the best mode in a patent application?

The answer, at least for now, is yes.


35 U.S.C. 112, first paragraph clearly states that best mode shall be set forth.Even though failure to set forth the best mode may not result in a canceled or invalid claim, there may be other negative consequences of failure to set forth best mode.

In any case, patent attorneys and patent applicants would be wise to follow an abundance of caution approach and continue to set forth best mode.

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