Abstract
On October 1, 2015, all US hospitals will be required to transition from using ICD-9-CM codes to ICD-10-CM codes for billing and administrative purposes. This study describes the lessons learned from a statewide syndromic surveillance system, NC DETECT, for handling the transition. This study describes the updating of existing surveillance case definitions to ICD-10-CM, the development of new ICD-10-CM case definitions, the challenges and rewards of the transition to ICD-10-CM, and an assessment of the updated case definitions used in syndromic surveillance of emergency department data.