Two major public school systems in Northern Virginia are moving ahead with plans to welcome small groups of students back into classrooms starting next month, as novel coronavirus cases trend downward in the Washington region.

The school boards of Fairfax County Public Schools and Loudoun County Public Schools voted in meetings on Tuesday evening to approve separate but similar plans laid out by the superintendents of the two systems that follow what is known as a “cohort” approach. Under this program, certain categories of students will come back in phases over the next six weeks.

Both school systems are prioritizing students typically seen as most likely to fall behind during online learning: those with learning disabilities, English-language learners and very young children.

In Fairfax, which serves 189,000 students, the first batch of 62 students — those taking career and technical education courses, which are difficult to pursue remotely — will return in early October. By mid-October, preschoolers with autism, some other preschoolers and more career and technical education students will return, bringing a total of 1,734 students back to classrooms.

By mid-late October, nearly 4,000 students will return, according to the plan, including English-language learners and some students at the secondary and elementary school level. By late October, high-schoolers taking courses that “benefit strongly from in-person hands-on experiences” will return.

The students invited back to classrooms will follow a range of plans: Some will learn in-person for four full days every week, others for just one or two days per week. The school board voted to approve the plan 8 to 3, with one abstention.

Loudoun, which serves 83,000, has offered more specific dates. The school board had approved a plan in August that allowed 900 high-schoolers at the Monroe Advanced Technical Academy, which offers vocational classes, to return for in-person learning on Sept. 8 — which they did. That previously approved plan also calls for schools to allow some children with disabilities to return to classrooms starting Oct. 13, which the school system still plans to do.

On Tuesday, the board voted unanimously, 9 to 0, to advance to the next stage of the plan: Loudoun will welcome roughly 7,000 kindergartners, first-graders and second-graders to classrooms two days a week starting Oct. 27.

Fairfax and Loudoun’s announcements come as new research suggests school systems that have reopened are seeing extremely limited spread of the coronavirus.