Can failure to disclose the best mode be grounds for patent invalidity?

Yes, failure to disclose the best mode can be grounds for patent invalidity. However, it’s important to note that this only applies to patents issued from applications filed before September 16, 2011. As stated in MPEP 2165:

“The failure to disclose the best mode is a basis for a defect under 35 U.S.C. 282 (b)(3)(A). This basis for invalidity only applies to patents filed before September 16, 2011.”

For applications filed on or after September 16, 2011, failure to disclose the best mode is not a basis for invalidating or rendering a patent unenforceable. This change was implemented by the America Invents Act (AIA).

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Topics: MPEP 2100 - Patentability, MPEP 2165 - The Best Mode Requirement, Patent Law, Patent Procedure
Tags: America Invents Act, Best Mode, patent enforcement, Patent Invalidity