Enrollment in D.C. Public Schools fell by hundreds of students this academic year, spoiling hopes of city education leaders who predicted more families would return to campuses in the third school year altered by the pandemic.

About 49,000 students attend school in the city’s traditional school system, according to preliminary data released Tuesday by the Office of the State Superintendent of Education (OSSE). That’s about 850 fewer students than last year.

City officials said they are still studying the data. A more detailed breakdown of enrollment numbers by grade level won’t be publicly available until next year.

Based on a review of the early information, Deputy Mayor for Education Paul Kihn pointed to several factors that could explain the drops: more families moving out of the District; parents choosing to homeschool; and fewer students enrolling in preschool, which also experienced steep drops last year.

“We expected that we would see our pre-K and early childhood grades come back more strongly,” Kihn said. “We did not see that happen.”

Overall enrollment in all the District’s public schools — traditional and charter — remained flat at about 93,840 students, according to OSSE. That’s because charter school enrollment grew by nearly 1,000 students, which Kihn attributed to new school openings and expansions at existing campuses.

Public school enrollment fell across the country during the pandemic, with earlier grades sustaining the greatest drops. Federal data show pre-K enrollment tumbled by 22% in the 2020-21 academic year and kindergarten enrollment fell by 9%.

School funding nationwide is largely determined by enrollment numbers so campuses that educate fewer students could receive fewer dollars.

D.C. Public Schools Chancellor Lewis Ferebee said the school system would redouble efforts to recruit families for preschool. He acknowledged some families are still worried about sending their children to school during the pandemic, especially if they are too young for a COVID-19 vaccine.

The stakes are high: studies show preschool helps build a foundation for academic success later in life. It also serves as an entry point for families into the school system, which could determine future enrollment in later grades.

“We know this is critical because this allows us to build a strong elementary cohort and could have lasting effects for elementary, middle and high school grades,” Ferebee said.

It is the second consecutive year the school system’s enrollment dropped. It follows a decade of mostly steady growth — the school system reached an enrollment high in 2019-20 when it educated more than 50,000 students.

Officials had hoped enrollment would rebound this academic year. During the last budget cycle, D.C. Public Schools projected enrollment would jump to 52,000 in 2021-22.

Most students who left their schools at the end of last year did not transfer to another campus within the city but moved out of the District entirely, according to city officials. It is hard to pinpoint exactly how many of those departures are because of the pandemic.

Chelsea Coffin, who directs education research at the D.C. Policy Center, said birth rates in the District have declined since 2016, a possible indicator that fewer students can be expected to enroll in school.

She also pointed to research from CBRE, a real estate and investment firm, which found D.C. and other expensive coastal cities experienced some of the highest levels of people moving away during the pandemic.

Some of those families may have left the city because they lost employment and needed to find more affordable housing, she said. Others with remote-friendly work options may have left to live elsewhere.

Kihn said the uncertainty of the pandemic makes it difficult to figure out what current enrollment means for coming years.

“This is one of the challenges that we currently have as we try to interpret the public school trends,” he said. “So much of our public school enrollment and so much of family decisions have been predicated on family circumstances.”