Currently only New Hampshire, New Mexico, North Dakota, Oregon, Tennessee, and West Virginia require MRI technologists to be licensed. Requirements vary by state.
Optional certification is available. Many employers prefer to hire certified MRI technologists. Certification can be obtained through the American Registry of Radiologic Technicians (ARRT) or the American Registry of Magnetic Resonance Imaging Technologists (ARMRIT).
For more information on certification, go to: