- Level 3 (lowest level): This level implies that, with modest augmentation, the lead agency or program can address the primary needs of the response. In the United States, many small natural disasters or environmental responses fall into this activation level. An example is the CDC response to the 2016 water contamination crisis in Michigan.
- Level 2 (intermediate level): This level implies substantial augmentation is required for the lead agency or program to meet response requirements. For CDC, the response to the 2011 Japan earthquake, tsunami, and nuclear disaster was a Level 2 activation.
- Level 1 (highest level): This level requires an agencywide response and often includes domestic and international partners. As an example, CDC has recorded four Level 1 activations: Hurricane Katrina (2005), influenza A (H1N1) pandemic (2009–10), Ebola virus disease outbreak (2014–2016), and Zika virus outbreak (2016–2017).