What makes me eligible to file?

There’s a good chance you’ll qualify if you’re not working and not being paid as a result of the coronavirus outbreak. Workers who were furloughed or quarantined without pay, for example, would be eligible. But states are still wrestling with who exactly will qualify as quarantined, experts said.

The federal law is somewhat flexible, so states can tweak their laws to provide benefits in several situations that are likely to play out, according to the Department of Labor, which recently issued guidance to states.

A state could decide to provide benefits, for example, to employees of a company that stopped operating because of the coronavirus. It could also provide benefits to quarantined workers who would not otherwise be paid but expect to return to work after the quarantine is over. The law also goes as far as permitting states to provide benefits if employees stopped working because they were at risk of being exposed, were infected or were left to care for a relative.

Many states have started making these changes, but that doesn’t mean all states will.

Can I apply even if I’m technically employed?

Probably. Let’s say you’ve exhausted any employer-provided sick or family leave, or you’ve run through any emergency paid sick and paid family leave that you may eventually receive as part of the legislation lawmakers are working on. Maybe you’re not eligible for some or all of these benefits.

If you’re quarantined or have been furloughed — and you’re not being paid but expect to return to your job eventually — you may be able to get unemployment benefits.

Can I apply if my pay has been reduced?

Probably. Every state has some kind of partial coverage that allows unemployment insurance to replace part of your pay if hours are reduced, Ms. Evermore said. But the amount replaced varies quite a bit by state.

Who is left out?

Roughly half of states do not cover part-time workers, said Andrew Stettner, a senior fellow at the Century Foundation, a public policy research group, and many states have made it more difficult for temporary workers to get coverage.