In March 2026, the Census Bureau released its population estimates for counties across the United States. The data show how the District of Columbia has fared demographically relative to its urban neighbors in the broader D.C. region. In 2025, the District’s population grew by 0.3 percent—below Alexandria’s 0.8 percent and Arlington’s 1.8 percent. Beyond these headline figures, two trends emerge from the data. First, the District’s domestic migration rate has had a flatter trajectory than that of its urban neighbors. Second, the District’s declining birth rate stands out relative to the stable birth rates of its urban neighbors.
While more people have been leaving the District than moving in every year between 2021 and 2025, the rate at which residents have been leaving the city (domestic out-migration) has fluctuated less. In 2021, people left D.C. at a lower rate compared to its urban neighbors, and the subsequent easing has also been more muted. The District’s rate of domestic out-migration eased from 9.3 per 1,000 people to 6 per 1,000 in 2025. Nevertheless, more people continue to leave the District than move in.
Arlington and Alexandria—the two other urban jurisdictions in the D.C. region—provide instructive contrasts with the District. In 2021, Arlington experienced substantial domestic out-migration—at an approximate rate of 30 per 1,000 people. Four years later, Arlington’s domestic migration rate turned barely positive. Domestic migration in Alexandria followed a similar arc but its rebound recently faltered. In 2025, Alexandria had the highest rate of domestic out-migration of any urban jurisdiction in the D.C. region at nearly 14 per 1,000 people. Only Arlington posted a positive domestic migration rate.
Birth rates have been declining faster in the District than in neighboring urban jurisdictions. Put simply, fewer babies are being born. Between 2021 and 2025, the birth rate in D.C. fell from approximately 12.7 to 10.6 per 1,000 people. By contrast, birth rates in Arlington and Alexandria barely changed over the same period — though Arlington’s 2025 rate, while stable, remained the lowest among the region’s three urban jurisdictions.
One consequence of a declining birth rate in the District —combined with the city’s continuing out-migration—will be lower enrollment in its public schools. Research by the D.C. Policy Center’s Education Policy Initiative suggests that while D.C.’s public school system is overall stable, enrollment in earlier grades—and especially pre-kindergarten—will face the greatest strain from fewer births. But schools in Arlington or Alexandria may not be spared. Arlington’s stable but stagnant birth rate, if not offset by young families moving in, could create enrollment pressure over time, while schools in Alexandria may face enrollment difficulties because people are still leaving the city at a relatively high rate.
In sum, the 2025 data highlight the challenges facing the District relative to its urban neighbors. Though domestic out-migration has persisted, the District’s domestic migration rate has followed a more muted trajectory than those of Arlington and Alexandria. At the same time, the District has seen a notable decline in its birth rate—a trend that is likely to have material consequences for public school enrollment.
Data notes:
- The 2025 county population estimates can be accessed here.
- The authors follow the urban classifications in the 2025 State of the Capital Region report produced by George Washington University’s Center for Washington Area Studies.