Fairfax County Public Schools, one of the country’s largest districts, is asking families to choose between 100 percent virtual learning or part-time in-person schooling next year, one of the first concrete plans for fall released by schools nationwide.

The superintendent of the Northern Virginia district, which serves 189,000 students, announced the setup to parents in an email Wednesday morning, writing that all families will be able to choose between two enrollment options for the 2020-2021 school year.

In the first, students will receive “virtual, interactive instruction” four days each week, and they will never set foot on campus. In the second, students will attend school for at least two “full days” of instruction inside school buildings and participate in independent study and work on the remaining days.

“Our first preference, of course, remains 100 percent in-person learning . . . however, based on current health data, that seems unlikely,” Superintendent Scott Brabrand wrote in the email. “In developing this plan, our first priority is the health and well-being of our students and staff.”

Those who do choose to enter schools will have to follow “social and physical distancing recommendations” in classrooms, on buses and in all shared spaces, Brabrand wrote. That means students and staffers will remain six feet apart, reducing capacity inside school buildings — which is why, Brabrand wrote, the option for in-person school is currently limited to two days of instruction each week.

Depending on how many families choose full-time virtual education, Brabrand wrote, the school may be able to offer more than two days of face-to-face teaching.

Regardless, one day each week will be set aside to allow teachers to plan and give extra support to students who need it, according to the email. The school system is also exploring ways it can give “increased in-person or synchronous instruction” to special education students and English language learners, Brabrand wrote.

He promised to release more information about Fairfax’s reopening plans in coming weeks, as administrators continue to finesse the details. He also promised that teachers will be surveyed for their preferences on how best to return to school.

Staffers and families said the superintendent’s plans raise more questions than answers. Parents said they feel unclear about what forms of education, exactly, are being offered — will the virtual schooling be an in-home replica of the school day, or will it just be a half-hour of video class each day? And some are concerned that the proposed setup could force already stressed and struggling parents to balance child care with work responsibilities for more than a year to come, which could prove an impossible task.

“There are people in this county who do not have the resources or the flexibility to do this for another nine months,” said Robb Watters, father to a Fairfax County third-grader.

Some educators, meanwhile, said the return to in-person schooling may be premature.

“We must not rush,” Kimberly Adams, president of the 4,000-strong Fairfax Education Association, wrote in a statement. “FCPS should not return to in-person learning until a vaccine or approved treatment is widely available.”

Becca Ferrick, president of the Association of Fairfax Professional Educators, which represents 1,800 educators, said she is preparing questions for administrators ahead of a meeting later this week. Among them are queries about which teachers will be allowed to work virtually, whether teachers will be required to submit medical information to request a virtual teaching position, and whether educators offering virtual and face-to-face instruction will be asked to follow the same curriculum at the same pace.

In an interview, Ferrick praised the plan for giving families and employees more choice. But it’s still nowhere near sufficient, she said.

To be fair, “a solution . . . simply doesn’t exist,” Ferrick said. “They are trying to make definite plans in a situation that is completely unpredictable and ever-changing — like trying to chart a straight course through a hurricane.”

Fairfax is one of the first districts in Virginia to release specific, detailed plans for the fall. Nearby Loudoun County Public Schools last week announced a tentative plan that would permit its 84,000 students to learn in person two days a week, while spending three days learning virtually at home.

The Fairfax announcement also comes after a troubled rollout of online learning last semester, in which the school system suffered privacy breaches, online harassment and multiple technical failures. The fiasco ultimately led to the resignation of the school system’s longtime information technology chief.

In the waning weeks of the semester, Fairfax appeared to find a solution — which partly involved switching some functions of online learning to the Google Classroom platform — that worked well for many teachers and students. But some frustrated parents had already chosen to pull their students from the system, and the previous difficulties may complicate some families’ enrollment decision for next year.

Brabrand wrote that, if the state of Virginia moves beyond Phase 3 of Gov. Ralph Northam’s (D) reopening process, the school may be able to bring everyone back into the buildings on a “full-time, pre-COVID basis.” The state is in Phase 2 but could move into Phase 3 this month, which would reopen child-care services and allow for gatherings of up to 250 people.

“But until that time, we believe the back to school model described in this letter — while not a perfect solution — best addresses the concerns and desires we have heard,” Brabrand wrote, “about reopening schools in a safe and responsible manner.”

Families in Fairfax must submit their preferences to the school system by July 10, Brabrand wrote, so administrators can begin to properly plan for the first day of class on Aug. 25.

Watters, parent to the third-grader, plans to wait another week or so before making his decision. He wants to see whether the school system will offer more specific information or proof that it has solved its technical troubles.

“But if we go into this year and it resembles anything like what happened last semester,” Watters said, “I would seriously consider moving my daughter to private school.”