The United States, unlike the European Union, has maintained population growth through a combination of natural increase (births minus deaths) and net international migration. However, the balance between those two factors has shifted dramatically in recent years.
From 2012 through 2020, the United States continued to experience natural population growth, though the rate slowed steadily. Declining birth rates—especially among younger women—and rising death rates from an aging population, drug overdoses, and COVID-19 have eroded natural increase as a driver. According to the U.S. Census Bureau, by 2021, natural increase nearly stalled. In 2021, the country recorded the lowest natural increase in over a century. Births barely exceeded deaths by about 142,000. In 2022, that margin widened slightly, but the trendline points to natural decrease within the next decade unless fertility rises significantly or mortality falls.
Immigration has filled that gap. Net international migration became the dominant driver of population growth in the United States by 2022, echoing the European pattern. In 2023, net migration accounted for nearly 80% of U.S. population growth. The Census Bureau reported an increase of roughly 1.6 million people from net migration in 2023—the highest since 2017. This surge followed pandemic-era restrictions that had driven numbers sharply lower in 2020 and 2021.
While the U.S. still records slightly more births than deaths nationally, over half of all counties reported natural decrease in 2022. That figure continues to climb, especially in rural areas and Rust Belt states. Growth remains concentrated in urban and Sun Belt regions, where international migrants settle and younger families concentrate.
The long-term trajectory shows the U.S. heading toward the European demographic model unless policy, immigration flows, or reproductive trends change. The U.S. replacement-level fertility rate is 2.1, but the national average stands below 1.7. Without immigration, the population would stagnate or decline.
In contrast to the EU, where population decline has already taken root in multiple countries, the U.S. remains demographically younger overall. However, the margin is narrowing. Immigration—legal and otherwise—has become the single point of demographic leverage. Without it, the U.S. enters the same demographic contraction cycle that Germany, Italy, Spain, and much of Eastern Europe have endured for years.
While the U.S. has not yet experienced annual deaths exceeding births at the national level, it is following the same trend. Immigration now accounts for nearly all population growth. Without it, demographic decline becomes a near certainty before 2040.
