(CNN) A school district in New York has canceled classes and activities until next week because a faculty member contracted the novel coronavirus.

Seattle Public Schools, near the epicenter of an outbreak in Washington, says a staff member tested positive for the virus this week, triggering closures for a minimum of 14 days.

And another district nearby has closed for up to two weeks and transitioned to "online learning" because a parent in the district has also contracted the disease.

But as other schools deliberate shutting their doors to slow the spread of the coronavirus, some parents may be left to wonder: If schools close, how will my child eat?

Across the United States, millions of students rely on school lunches, more than 20 million of which are distributed for free each day, according to the US Department of Agriculture

If classes are canceled, figuring out how to provide those meals to students is a challenge, with a web of federal rules governing when and where students can receive food.

While regulators have eased some of those restrictions due to the coronavirus pandemic, school closures remain "an evolving situation with many unknowns and complex considerations that vary from one community to the next," said Diane Pratt-Heavner, a spokesperson for the School Nutrition Association.

Federal waivers relax rules for coronavirus closures

When schools close unexpectedly -- during a pandemic , for example -- the USDA allows them to provide food to students using programs designed for summer meals, which are often offered at churches, parks and other community sites.

Schools can then be reimbursed by the federal government for the meals they provide, just as they would be during the summer, according to a USDA memorandum issued last year.

The catch, according to the School Nutrition Association, is that the meal distribution sites, including unused schools, must be located in areas where at least half of children come from low-income families.

Using those sites is a "first step that gives schools in many low income communities the option to continue some form of meal service during coronavirus school closures," but the reality is that "needy students live in all communities," said Pratt-Heavner, whose group represents school nutrition professionals.

Underscoring the complex bureaucracy that governs school lunches, meals distributed during unexpected closures also typically have to be eaten in " congregate feeding " sites intended to encourage community bonding.

But federal health officials have warned that students should avoid eating in large groups during the coronavirus outbreak, and the USDA issued waivers this past weekend to allow to-go meals in two states hardest hit by the coronavirus epidemic, California and Washington.

Sack lunches and grab-and-go foods

In Washington, a state that has seen more than 200 coronavirus cases, the Northshore School District has moved classes online because a parent tested positive for the coronavirus.

The district, which said it would not have in-person classes for up to two weeks, is offering meals for pick up at 22 school sites. Five production sites are making grab-and-go meals, according to Juliana Fisher, the district's director of food and nutrition services.

And while school closures are always a last resort, some of the nation's largest districts are also making plans to feed students if the coronavirus forces them to shut down.

Not far from the early epicenter of the US outbreak, for example, Seattle Public Schools prepared "to provide sack lunches prepared by staff in our central kitchen," according to Tim Robinson, a spokesperson for the district.

The NYC Department of Education, which serves more than a million students, said that "if a school is closed for 24 hours, we're prepared to serve grab-and-go breakfast and lunch for any student who wants it," according to spokesperson Miranda Barbot.

Miami-Dade County Public Schools, also one of the nation's largest school systems, said it would work with state and federal officials to "ensure that students in any affected schools are provided with the meals they have come to depend on," according to spokesperson Jackie Calzadilla.

And Chicago Public Schools, which currently has one school closed, has "established a special hotline and email for those families who need support with meals or have additional questions," said Emily Bolton, a district spokesperson.

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Many schools are preparing to provide meals during potential coronavirus closures. But what those will look in practice -- especially if closures are widespread and prolonged -- remains to be seen.

In California, for example, a spokesperson for the Los Angeles Unified School District, Shannon Haber, said that schools are operating normally. But "we are planning for everything," she said. "Meals to students included."

Asked how meals would be distributed and what parents can expect, though, her response was brief: "I have no further information at this time."