Ten US states are in states of emergency over COVID-19, the disease caused by the novel coronavirus that’s sickened over 110,000 people around the world and over 500 in the US. There’s an outbreak of the virus at a nursing facility in King County, Washington, and 18 people in the state have died. Dozens of counties have also declared emergencies, and the entire country has been under a federal public health emergency since the end of January.

Emergency declarations allow officials at the federal, state, and local levels to mobilize quickly and activate a menu of powers that they can use to respond to a crisis situation. “They allow expedited response efforts in ways that don’t circumvent constitutional protections,” says James Hodge, director of the Center for Public Health Law and Policy at Arizona State University. “It lets people say, we have to quarantine 100 people right now, we’ll do that.”

At the federal level, a public health emergency gives the Department of Health and Human Services (HHS) more flexibility to help states respond to a threat. If necessary, it also lets HHS suspend or modify some laws, like parts of the HIPAA privacy rule or laws requiring that medications only be given out in health care facilities.

State and local governments, though, are where the action is, Hodge says. While the federal government took the first steps to respond to the novel coronavirus and placed people in federal quarantine for the first time in 50 years, they won’t be able to sustain those types of practices. “They’re heavily reliant on state and local authorities to do that,” he says.

State and local governments are where the action is

Actions available to states might vary, but they can include the ability to require people to isolate or quarantine, school or event shutdowns, and curfews. States might let medical professionals who are licensed in other places practice there or allow health care volunteers to handle low-level medical tasks under the supervision of a doctor. A state might take all or none of those steps; they’re just some of the options available.

But an emergency declaration was why Washington’s King County was able to quickly purchase a motel to isolate patients with COVID-19. In San Diego County, California, a local emergency declaration increased resources for beds at local hospitals, and in Solano County, it created an operations center to facilitate screening.

It’s not always the case that states have to declare an emergency to tap into additional sources of funding, though, Hodge says. “Some states might say that they’re issuing an emergency to tap into the funds,” he says, but some may be able to pull in money without one. In New York, for example, Gov. Andrew Cuomo appropriated $40 million to the state Department of Health without declaring an emergency.

The types of emergencies declared determine who takes charge of a crisis. If there’s an emergency declaration made, that tends to put emergency management experts at the head, Hodge says. A public health emergency, on the other hand, puts departments of health in charge. That’s what happened at the federal level in the US, and that’s why HHS is leading the response to COVID-19. The state of Florida also declared a public health emergency.

The types of emergencies declared determine who takes charge of a crisis

Not all states have laws that allow for public health-specific emergencies, though. “For those states, the route is an emergency or disaster declaration,” Hodge says. In those cases, the general emergency declaration policies include health emergencies, he says.

Right now, only two states have declared emergencies, but that’s likely to change as the outbreak of the novel coronavirus in the US continues to unfold. Until this week, only a very limited number of people in the US were being tested for COVID-19. Testing is set to expand as more states receive permission to run their own tests. With more testing, doctors are likely to find more cases — genetic evidence suggests the virus has probably been spreading undetected for the past few weeks in Washington state, for example.

States might analyze the risks and benefits of declaring a disaster in different ways. Some might take more time to watch and wait because emergency declarations can hurt economies, Hodge says. “[Florida Gov. Ron] DeSantis knows this is going to hurt business badly. In the same vein, if you have unknown cases running around, you have to take that seriously.”

Meanwhile, at the federal level, the Federal Emergency Management Agency (FEMA) is readying for the possibility that President Trump would make an emergency declaration, reported NBC News. That would come in addition to the public health emergency declaration at HHS, and it would bring in the agency for additional disaster support.

FEMA isn’t usually called on for public health emergencies. After Hurricane Katrina, efforts to improve health response during disasters shifted responsibility for pandemic and disease response to HHS, under the Pandemic and All-Hazards Preparedness Act. “HHS would have the lead and keep it, but FEMA might have a role in emergency management, but not in disease prevention,” he says. For example, they might be called on to help build quarantine facilities, if needed.

This is the first real public health threat faced by the Trump administration, and Hodge says he’ll be watching closely to see how far the administration will go in their response. Conflicts between states and the federal government over response to the virus have started already and will likely continue, he says. The California city of Costa Mesa already sued to prevent people in federal quarantine at a military base from being relocated within city limits, for example. The federal government eventually scrapped the plan. Officials in San Antonio, Texas, sued the Centers for Disease Control and Prevention over the release of quarantined people as well.

“We’re seeing how far the feds will go, and how the states will react,” Hodge says. “It’s going to result in some testy legal battles.”

Correction March 3, 5:40PM ET: An earlier version of this story included a misspelling of King County. We regret the error.

Update March 9, 1:46 PM ET: Updated with the latest number of states that have declared emergencies.