What is the impact of a species restriction on patent prosecution?

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.

A species restriction in patent prosecution can significantly impact the examination process and the scope of patent protection. The MPEP 806.04 outlines the following effects:

• The applicant must elect a single species for initial examination.
• Non-elected species are withdrawn from consideration.
• If a generic claim is later found allowable, withdrawn species claims may be rejoined.

The restriction can lead to a more focused examination on the elected species, potentially resulting in faster prosecution. However, it may also require the filing of divisional applications to pursue protection for non-elected species, which can increase costs and complexity for the applicant.