First responders and EMTs are required to practice under the direction of an EMS medical director. The trained individual must apply for local credentialing from each EMS provider with which they are affiliated.
"Credentialing" is a term being used nationally. The National Highway Traffic Safety Administration (NHTSA), National EMS Scope of Practice Model (PDF, 1.2 MB) states that "credentialing is a local process by which an individual is permitted by a specific entity (the medical director) to practice in a specific setting (with an EMS agency or organization)." While EMS personnel will be state licensed, they must be locally credentialed with an EMS agency/organization in order to practice.
Any advanced skills may only be performed under medical direction (approved local credentialing).