The CDC has issued guidelines for re opening. The CDC plan is a multi phase approach addressing business, education, healthcare, and individuals.
The CDC guidelines assign the following criteria for state or regional openings.
Downward trajectory of documented cases within a 14-day period
Downward trajectory of positive tests as a percent of total tests within a 14-day period (flat or increasing volume of tests)
The CDC states: "State and local officials may need to tailor the application of these criteria to local circumstances (e.g., metropolitan areas that have suffered severe COVID outbreaks, rural and suburban areas where outbreaks have not occurred or have been mild). Additionally, where appropriate, Governors should work on a regional basis..."