Some cities or states will recover sooner than others. It’s helpful to have criteria by which cities or states could determine they’re ready. A recent American Enterprise Institute report by Scott Gottlieb, Caitlin Rivers, Mark B. McClellan, Lauren Silvis and Crystal Watson staked out some goal posts.

Hospitals in the state must be able to safely treat all patients requiring hospitalization, without resorting to crisis standards of care.

Other cities and states fear that they will approach New York City’s state of crisis. They’re trying to increase the number of available beds and ventilators — as well as doctors, nurses and other health care providers — to make sure they aren’t overwhelmed in their capacity to provide care to all those who need it.

This is the most immediate bar, and the focus of most public health officials’ attention. At the moment, there’s no reason to believe any area is over a surge of cases, and analysts’ models predict many places won’t peak for weeks to come.

A state needs to be able to at least test everyone who has symptoms.

Dr. Gottlieb and colleagues estimate that the nation would need to have the capacity to run 750,000 tests a week — this is after things have calmed down greatly. There are times we might need even more.

“The 750,000 number should be viewed as a reasonable expectation for when we haven’t been having any major pockets or regional outbreaks to manage,” said Mark McClellan, an author of the report and a professor of business, medicine and policy at Duke. “If more testing to help contain outbreaks and potential outbreaks is needed, which seems very plausible, especially early on, the number would need to be significantly larger. We’ll also have to do some surveillance of people without symptoms, especially in higher-risk settings.”

A national estimate means less in deciding whether a state can reopen than its local capabilities. A state would need to be sure it could test every single person who might be infected, and have the results in a timely manner. That would be the only way to achieve the next requirement.

The state is able to conduct monitoring of confirmed cases and contacts.

A robust system of contact tracing and isolation is the only thing that can prevent an outbreak and a resulting lockdown from recurring. Every time an individual tests positive, the public health infrastructure needs to be able to determine whom that person has been in close contact with, find those people, and have them go into isolation or quarantine until it’s established they aren’t infected, too.

This will be a big challenge for most areas. Other countries have relied on cellphone tracking technology to determine whom people have been near. We don’t have anything like that ready, nor is it even clear we’d allow it. The United States also doesn’t have enough people working in public health in many areas to carry out this task.