Which age group is the fastest growing in the US? An analysis of recent demographic trends

According to the U.S. Census Bureau, the population of Americans aged 65 and older grew nearly five times faster than the total population over the century from 1920 to 2020. This rapid increase is largely driven by the aging Baby Boomer generation, leading to a profound demographic shift, and confirming which age group is the fastest growing in the US. The implications of this growth are widespread, affecting everything from social services to the economy.

Quick Summary

The older adult population, specifically the 65 and over demographic, is expanding at an unprecedented rate due to increasing longevity and the aging of the Baby Boomer generation. This demographic change has significant societal consequences.

Key Points

• The 65+ demographic is the fastest growing: Driven primarily by the aging Baby Boomer generation, the population of Americans 65 and older is expanding at an unprecedented rate.

• Seniors outnumber children in some areas: The rapid increase in the older population is compounded by a declining population of children in many U.S. metro areas, shifting the median age upward.

• The oldest-old segment is booming: Within the 65+ group, the population of individuals aged 85 and older is the fastest growing, projected to more than double by 2040.

• Immigration plays a key role: Higher birth rates among immigrant populations help to counteract the declining native-born youth population, mitigating the pace of national aging.

• Economic and social impacts are widespread: This demographic shift affects everything from the labor force and housing market to government programs like Social Security and Medicare.

• Longevity is increasing: Advances in healthcare and improved living conditions contribute to longer life expectancies, further accelerating the growth of the older population.

• Future growth relies on immigration: The Congressional Budget Office projects that immigration will account for all U.S. population growth starting in 2040, as births continue to lag behind deaths.

The Rapid Rise of the Older Population

Recent data from the U.S. Census Bureau confirms that the population of Americans aged 65 and older is expanding at an unprecedented rate. Between 2010 and 2020, this age group saw its largest 10-year numeric increase, adding 15.5 million people. This growth is primarily fueled by increased life expectancy and the aging of the large Baby Boomer generation (born 1946-1964).

The Impact of the Baby Boomer Generation

Starting in 2011, Baby Boomers began turning 65, significantly increasing the older population. Their large numbers mean they are expanding the ranks of seniors more than any previous generation. By 2030, all Baby Boomers will be over 65, and the 65 and older population is projected to reach 78.3 million by 2040.

Other Contributing Factors to Population Aging

Beyond the Baby Boomers, other factors contribute to the aging U.S. population:

• Increased Longevity: Medical advancements have led to longer life expectancies. The 85 and older group is the fastest growing within the older population, expected to more than double by 2040.
• Declining Youth Population: In contrast to senior growth, the child population is shrinking in many areas. Between April 2020 and July 2023, the number of U.S. children decreased by 3.3% nationally. This disparity raises the national median age.
• Regional Variations: While aging is a national trend, some areas like Florida and Arizona have higher median ages due to retirement, while others like Utah have lower median ages. In states like Maine, older adults outnumber children.

Comparison of Age Group Growth Rates (2010-2022)

The table below, using USAFacts data based on U.S. Census Bureau reports, compares growth rates of different age groups.

Age Group	Percentage Change (2010–2022)	Key Driver(s)	Societal Impact
65 and older	+42.8%	Aging Baby Boomers, increased longevity	Increased demand for healthcare, social security, and elder care services
20 to 34	Modest Growth	Population dynamics of Millennials	Changes in labor force composition, housing market demand
35 to 49	Modest Growth	Population dynamics of Millennials and Gen X	Impact on mid-career workforce and family structures
50 to 64	Modest Growth	Aging of Gen X, some later Boomers	Preparations for retirement, effects on experienced labor pool
0 to 4	-8.2%	Declining fertility rates	Reduced demand for pediatric services, changes in school systems

Economic and Societal Implications

This demographic shift has significant consequences. A smaller working population supports a larger retired one, impacting programs like Social Security and Medicare. Population growth is projected to slow, with immigration becoming increasingly vital. An older population also changes market demands towards healthcare and senior services. The workforce sees more older adults working longer.

The Role of Immigration

Net immigration helps counterbalance aging, as immigrant populations are generally younger with higher birth rates. The CBO projects immigration will account for all U.S. population growth starting in 2040. This influx offsets declining native-born birth rates.

Conclusion

The oldest age groups are growing fastest, driven by Baby Boomers, lower birth rates, and immigration's offsetting effects. U.S. Census Bureau data clearly shows the 65 and older demographic is expanding faster than any other. This trend will continue to shape U.S. society, presenting both challenges and opportunities.

Source: U.S. Census Bureau

Frequently Asked Questions

Why is the 65 and over age group the fastest growing?

The primary drivers are the aging of the large Baby Boomer generation, born between 1946 and 1964, and increased life expectancy due to advancements in healthcare and living standards.

How does the aging population affect the economy?

An aging population increases the demand for healthcare and elder care services while putting a strain on government budgets that fund social programs like Social Security and Medicare. It also shifts the composition of the workforce as more older adults work longer.

Is the number of children in the U.S. also increasing?

No, data shows that the population of children is declining in many parts of the U.S. Between 2020 and 2023, the U.S. child population dropped by 3.3% nationally.

What is the 'oldest old' demographic?

The 'oldest old' refers to individuals aged 85 and older. This segment is growing the fastest within the overall older population and is projected to more than double between 2022 and 2040.

How does immigration influence U.S. population growth by age?

Net immigration, particularly among Hispanic and Asian populations who are younger on average, provides a significant source of population growth that helps counteract the effects of a lower native-born birth rate.

By what year will all Baby Boomers be over 65?

All Baby Boomers will be over the age of 65 by 2030, marking a significant milestone in the country's demographic shift.

How does the median age in the U.S. compare to other countries?

While the median age in the U.S. is increasing, other developed countries like Japan have an even older population. The U.S. median age reached a record high of 39.1 in 2024, but Utah remains the youngest state with a median age of 32.4.