America's missing middle: The shrinking 45-64 population

America has a missing-middle problem — and this one is demographic.

Why it matters: The shrinking 45-64 population could leave fewer experienced adults to run institutions, mentor younger workers and care for the fast-growing population behind them.

• This is the Gen X-ish squeeze: The age group includes most of Generation X, plus younger baby boomers.
• It also overlaps with the "sandwich generation" years, when many adults are juggling children, aging parents, careers and their own retirement worries.

By the numbers: The U.S. population ages 45-64 fell by 2.68 million from April 1, 2020, to July 1, 2025, according to new https://www.census.gov/newsroom/press-releases/2026/vintage-2025-pop-estimates.html" target="_blank">Census Bureau population estimates reviewed by Axios.

• The group declined 3.2% nationally, from 84 million to 81.3 million.
• The Northeast had the steepest percentage drop, falling 7.1%.
• The Midwest fell 6.2%.
• The West fell 2.7%.
• The South was the only region where the 45-64 population grew — barely — adding 18,749 people, or 0.1%.

State of play: The decline is happening as the country gets older overall.

• The U.S. median age rose to 39.4 in July 2025, up from 38.6 in April 2020.
• The 65-and-older population grew 16.2% nationally during the same period.
• The under-18 population fell 2.4%.

Zoom in: The demographic math is catching up.

• The 45-64 group isn't vanishing so much as aging up: Younger boomers are moving into retirement age, and older Gen X cohorts are filling in behind them.
• Coupled with aggressive internal migration, high costs of living and housing shortages in the Northeast and West are driving this experienced cohort southward.

Context: Gen X is smaller than the baby boom because it was born during the https://www.pewresearch.org/short-reads/2018/03/16/how-millennials-compare-with-their-grandparents/" target="_blank">"baby bust" that followed the postwar birth surge.

• Birth rates fell sharply in the 1960s and 1970s as https://www.verywellhealth.com/a-brief-history-on-the-birth-control-pill-3522634" target="_blank">contraception became more widely available, women delayed marriage and childbirth and divorce and new family structures became more common.

Zoom out: The U.S. is not alone.

Other wealthy countries also are wrestling with aging populations, slower workforce growth and rising pressure on public budgets.

• With fewer peak-earning workers to tax, nations face compounding pressure on how to fund services for massive, aging populations (like Social Security and Medicare in the U.S.).

Gen X generally refers to people born from 1965 to 1980 — those now ages 45 to 61.

• Baby boomers were born from 1946 to 1964.

  Millennials were born from 1981 to 1996.

The intrigue: Gen X was the last generation to experience peak https://www.axios.com/2024/06/15/gen-x-school-racial-integration-brown-education" target="_blank">school integration.

• Today's shrinking 45-64 group includes many adults who came of age in schools with broader exposure to students of other races than the students who came after them.
• As this group ages out of workplaces, school boards and local civic life, communities of color could lose leaders shaped by that rare integrated moment — just as schools are becoming more https://www.axios.com/2024/05/17/suburban-schools-white-latino-segregation" target="_blank">segregated again.

Between the lines: Corporations and local governments should be on high alert, analysts say.

• The 45-64 demographic typically represents peak earners who anchor municipal tax bases and possess decades of institutional knowledge.
• A declining middle-aged group could gradually thin the ranks of experienced workers, caregivers and civic leaders.

Yes, but: Overall, the U.S. population is still growing.

• The aggregate growth masks the severity of the dip in the mid-career population.
• An area might boast top-line population gains while quietly losing the veteran teachers, senior managers and local leaders who typically keep many communities running.