Median age of population

The median age of the US population is estimated to reach 39.4 years in 2026, underscoring a steady aging trend. This shift reflects improvements in medical care and nutrition, alongside the continued aging of the baby boomer cohort, which together raise the share of older adults in the population. Lower fertility is reinforcing this pattern. The Congressional Budget Office projects that the total fertility rate will fall to about 1.58 births per woman in 2026, down from pre-2007 levels, meaning births are still occurring but not at a pace that would expand the proportion of younger Americans. At the same time, hospital survival rates are improving, keeping more people alive into older age. According to Vizient, key medical outcome indicators for hospitalized patients were about 30.0% better in the second quarter of 2025 than in 2019, reflecting advances in diagnostics and treatment. These gains contribute to higher longevity and add upward pressure on the median age, since more patients survive serious conditions and remain in older age brackets. In combination, declining fertility and improving medical outcomes point to a sustained increase in the median age over the coming years.

From 2021 to 2026, the US median age rose steadily, increasing 1.9% from 39.4 to 39.9 years as the population continued to age. The aging trend picked up in 2021 with a 1.6% jump, following the initial impacts of COVID-19. The brief dip in median age in 2020 (down 0.8%) reflected elevated mortality among older adults during the pandemic, which temporarily reduced the share of seniors in the population. Rapid vaccine rollout and better treatments in 2021 and 2022 supported a rebound among older cohorts, with median age growth of 1.6% and 0.5%, respectively. Continued gains in healthcare, booster campaigns and public health measures helped limit pandemic-related deaths among older adults. At the same time, persistently low birth rates reduced the share of younger people, adding further upward pressure on the median age.

Multiple structural forces are now pushing the median age higher in a durable way. Key drivers include gradual increases in life expectancy, ongoing medical and technological innovation, and sustained declines in fertility rates. Large baby boomer cohorts moving into and through retirement, coupled with better chronic disease management and more widespread preventive care, mean longevity gains are outpacing new births. Falling smoking rates and changing attitudes toward cigarettes have also improved health outcomes, reinforcing these longevity trends. Broader access to healthcare, stronger public health standards and continued subreplacement fertility are expected to keep the median age on an upward trajectory. As a result, the five years to 2025 marked a notable rise in demographic aging, with important implications for labor supply, healthcare demand and long-term economic planning.