What are the criteria for establishing distinctness between a combination and subcombination?

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.

To establish distinctness between a combination and subcombination, two criteria must be met:

• 1. The combination as claimed does not require the particulars of the subcombination as claimed for patentability (e.g., to show novelty and unobviousness).
• 2. The subcombination has utility by itself or in other combinations (MPEP § 806.05(c), subsection II).

The MPEP states: “To support a requirement for restriction between combination and subcombination inventions, both two-way distinctness and reasons for insisting on restriction are necessary, i.e., there would be a serious search burden if restriction were not required as evidenced by separate classification, status, or field of search.” (MPEP 806.05(a))