Before using the National Electronic Disease Surveillance System (NEDSS), CDC developed and used the National Electronic Telecommunications System for Surveillance (NETSS). NETSS is a computerized public health surveillance information system that provided CDC with weekly data regarding nationally notifiable diseases. NETSS continues to be used by reporting jurisdictions that are transitioning to the more robust NEDSS. A bare-bones approach for providing basic data and information, NETSS file content was not changed or updated substantially since NETSS launched in 1990. While the NETSS file format has changed little since 1990, NEDSS is flexible enough to update standards with new technology as epidemiology evolves. New technology has resulted in changes in laboratory tests and vaccinations, increased automation, and additional standards for electronically transferring patient and public health data. NEDSS embraces this newer technology so that NEDSS-compatible systems, including the NEDSS Base System (NBS), can provide the standards and tools required for health departments to receive data from laboratories through an automated system.