How should a Markush group be properly formatted in a patent 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.

A Markush group in a patent claim should be formatted as a closed group of alternatives. According to the MPEP 2173.05(h):

“A Markush grouping is a closed group of alternatives, i.e., the selection is made from a group ‘consisting of’ (rather than ‘comprising’ or ‘including’) the alternative members.”

The MPEP also notes that the specific format used is not critical, providing examples:

• “a material selected from the group consisting of A, B, and C”
• “wherein the material is A, B, or C”

It’s important to use closed language to clearly define the scope of the alternatives.