Many SEOs have been busy reverse engineering featured snippets to increase their odds of getting them.  But Gary Illyes from Google debunked one of the common rumors that has been floating around recently.

During his State of Search keynote Monday in Dallas, Illyes talked quite a bit about featured snippets and one thing he mentioned is that structured data markup does not influence or make a difference on a webpage earning the featured snippet in the Google search results.

That said, Illyes also mentioned that he is proposing using it in the future.  So structured data could potentially play a role in featured snippets sometime in the future.

Bottom line?  If you have pages that can take advantage of structured data, you might want to think about adding it to those pages so that if it does play a role in featured snippets in the future, your sites are ready to go.  But do be aware that there is a manual action associated with spammy structured data, so only use if when the pages should be showing it.