"The share of senior citizens in the U.S. population is projected to grow from 18.7% in 2025 to nearly 23% by 2050, while children under 18 decline from almost 21% to a projected 18.4%.
Without any immigration, the U.S. population will start shrinking in five years. That’s when deaths will surpass births, according to projections from the Congressional Budget Office, which were revised in September to account for the Trump administration’s immigration crackdown. Population growth comes from immigration as well as births outpacing deaths."