Currently, only New Hampshire, New Mexico, North Dakota, and Oregon require medical sonographers to be licensed. Requirements vary by state.
American Society of Radiologic Technologists
Optional certification is available through the American Registry for Diagnostic Medical Sonographers. For more information, contact:
American Registry for Diagnostic Medical Sonography
In addition, many employers prefer to hire sonographers who have a Basic Life Support certification, which shows they are trained to provide CPR.