From UFStarfleet Wiki
The First Contact Ribbon is awarded to any United Federation Starfleet Member or crew who made First Contact with a warp capable species. The First contact can not be in violation with the Prime Directive. The First Contact ribbon is only awarded when the First Contact mission was peaceful but does occasionally recognize contacts that begin hostile but end peacefully.
Addition of award to Service Jacket must be requested by member through the Service Jacket Update Request form after the completion of First Contact for the verification of the event, before the granting of the award.