Phase Description Approximate Population (millions) Cumulative Population (millions)
1aHigh-risk health workers16.216.2
1aFirst responders2.118.3
1bAll ages at high risk20.023.8
1bOlder adults congregate/overcrowded17.255.5
2K-12 teachers, staff, childcare workers9.164.6
2Critical workers in high-risk settings2.767.3
2Moderate comorbid conditions40.0107.3
2Homeless shelters1.0108.3
2Incarcerated people and staff2.7111.1
2All older adults13.2124.3
3Younger adults46.5170.8
3Children82.1252.8
3Workers in important industries27.5280.3
4Everyone else50.7331.0