CDC SVI Frequently Asked Questions (FAQ)

CDC Social Vulnerability Index (CDC SVI) is a tool that uses U.S. Census data to determine the social vulnerability of every census tract. ATSDR’s Geospatial Research, Analysis & Services Program (GRASP) maintains CDC SVI to help public health officials and local planners better prepare for and respond to emergency events like hurricanes, disease outbreaks, or exposure to dangerous chemicals.

Learn more about CDC SVI in the frequently asked questions and responses below.

Flood Protection Sandbags with flooded homes in the background (Montage)

For more information, please contact the CDC SVI Coordinator (

Page last reviewed: April 21, 2021