In 2011, the CDC released the PHIN Implementation Guide (IG) for Syndromic Surveillance v.1 under the Public Health Information Network. In the intervening years, new technological advancements, EHR capabilities as well as epidemiological and Meaningful Use requirements have led to the periodic update and revision of the IG through informal and semi-structured solicitation and collection of comments from across public health, governmental, academic, and EHR vendor stakeholders.