When is an applicant required to elect a single species?

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.

An applicant is required to elect a single species in several scenarios according to MPEP 808.01(a):

• When a requirement for restriction between either independent or distinct species is made
• In applications containing claims to a plurality of species with no generic claims
• In applications containing both species claims and generic or Markush claims

The MPEP states: “When a requirement for restriction between either independent or distinct species is made, applicant must elect a single disclosed species even if applicant disagrees with the examiner’s restriction requirement.” This election is necessary to focus the examination on a specific embodiment of the invention.