Emergency medical responder levels by U.S. state

In the United States, the licensing of prehospital emergency medical providers (emergency medical technicians (EMTs)) and oversight of emergency medical services are governed at the state level. Each state is free to add or subtract levels as each state sees fit. Therefore, due to differing needs and system development paths, the levels, education requirements, and scope of practice of prehospital providers varies from state to state. Even though primary management and regulation of prehospital providers is at the state level, the federal government does have a model scope of practice including minimum skills for EMRs, EMTs, Advanced EMTs and Paramedics set through the National Highway Traffic Safety Administration (NHTSA).
While states are able to set their own additional requirements for state certification, a quasi-national certification body exists in the form of the National Registry of Emergency Medical Technicians (NREMT). The NREMT offers a national certification based on the NHTSA National Standard curriculum for the levels of EMR, EMT, Advanced EMT and Paramedic. Individual states are allowed to use NREMT certification as part of their certification process, but are not required to. As of 2011, 38 states use the NREMT examination for EMT certification and 45 states use the NREMT examination for Paramedic certification. These levels are denoted below using an asterisk (*). At present time, use of the NREMT examination for EMT-Intermediate 85 and 99 have not been included in this list.
Any provider between the levels of EMT-Basic and EMT-Paramedic is either a form of EMT-Intermediate or an Advanced EMT. The use of the terms "EMT-Intermediate/85" and "EMT-Intermediate/99" denotes use of the NHTSA EMT-Intermediate 1985 curriculum and the EMT-Intermediate 1999 curriculum respectively. In addition, not all states use the "EMT" prefix for all levels (e.g. Texas uses EMT-Paramedic and Licensed Paramedic). Finally, some states have levels that have partially been phased out. While no "new" certifications are provided at this level, providers can sometimes be grandfathered in provided they meet recertification requirements. Any level that has been completely phased out (i.e. not used for new "or continuing" providers) is not listed.
In some states there are also EMS-RN's which is a Registered Nurse trained in Pre-Hospital response.
In the list, each state's certification levels are provided from most basic at the top to most advanced at the bottom.
Colorado.
Colorado EMS Scope of Practice and Education Standard Comparison
Iowa.
Transition to new levels began January 2011, and finished in March 2015. 
Utah.
Now have been phased out of the state of Utah:
Wyoming.
Wyoming has adopted the National Registry model with an addition of IEMT. The IEMT has all of the skills of an AEMT with the addition of additional medications, endotracheal intubation, cardiac drugs and skills (manual defibrillator, epi 1:10000, etc.) chest darts and pain management. National Registry is NOT required, and not accepted for licensing in Wyoming.