The number of Americans 65 and older is expected to nearly double by the middle of the century when they will make up more than a fifth of the nation’s population, according to a Census Bureau report released Tuesday.
By 2050, 83.7 million Americans will be 65 or older, compared with 43.1 million in 2012, the report said. Fewer than 10 percent were older than 65 in 1970.
While demographers have long projected a significantly older country later this century, declines in fertility and mortality rates are hastening the shift, leading to what are expected to be profound changes for issues ranging from Social Security and health care to education.
Signs of the change are underway: The Villages, a city in Central Florida with a large retirement community, was the nation’s fastest-growing metropolitan area from 2012 to 2013, according to the Census Bureau.
The report says the graying of the country would occur even as the population was projected to grow 27 percent — to 400 million in 2050 from about 314 million — and as minorities were expected to eclipse the non-Hispanic white population.
“International migration of people 18 to 64 has helped keep the nation younger, and that trend is expected to continue,” said Jennifer M. Ortman, chief of the Census Bureau’s Population Projections Branch and an author of the study.
In addition to the large number of baby boomers, Americans born from mid-1946 to mid-1964 who are now entering or approaching retirement, other factors contributing to the country’s aging include fewer people dying from smoking-related illnesses, the Census Bureau said.
In 1970, 45 percent of people ages 25 to 44 smoked, compared with 22.1 percent of that age group in 2011, according to the American Lung Association and the Centers for Disease Control and Prevention.
As one measure of how much longer people are living, Americans who were 65 in 1972 could expect to live 15.2 more years; in 2010, they were expected to live 19.1 more years, according to the Census Bureau.
The report said the United States would be among a number of nations with a large share of their populations older than 65, including nearly 33 percent of Japanese, 28 percent of Germans and 25.5 percent of Italians who will be 65 or older by 2030.