What happens if the elected species is not allowable in a Markush claim?

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.

If the elected species is not allowable in a Markush claim, the examiner will follow a specific procedure outlined in MPEP 803.02:

“If the elected species is not allowable, the examiner should extend the search and examination to the extent necessary to determine patentability of the Markush claim.”

This process involves:

• Determining the next species to be searched and examined
• Continuing this process until either an allowable species is found or the entire claim is determined to be unpatentable
• If no allowable species is found, the examiner should reject the Markush claim as unpatentable over the prior art

The applicant may then present arguments or amendments to overcome the rejection.