Pago Pago, AMERICAN SAMOA — U.S. population growth slowed in 2025 and is expected to decline eventually. In some large U.S. territories, however, the population drop has already begun and is projected to continue through the end of the century.

The U.S. Census Bureau updated long-range population estimates and projections for four U.S. territories and 21 countries yesterday.

The Census Bureau regularly develops population estimates and projections for over 200 countries and areas with populations of 5,000 or more. These updates integrate the latest available data and reflect recent changes in fertility, mortality and migration trends.

The IDB serves as an important resource for the U.S. government and the public by helping answer foundational questions about how populations are growing, aging or declining.

U.S. TERRITORIES

This IDB release is the first since 2017 to include updated estimates and projections of four U.S. territories: American Samoa, Guam, the Northern Mariana Islands and the U.S. Virgin Islands.

Three of the territories have been experiencing population declines for several years — and all four are set to shrink by 2100:

    •    The population in the Northern Mariana Islands had already begun declining at the start of our data series in 2000 and is projected to drop another 17% by 2100.
    •    The population in American Samoa started falling around 2010 and is projected to plummet another 61% by 2100.
    •    The U.S. Virgin Islands experienced its most rapid decline between 2010 and 2020 and is projected to lose 41% of its current population by 2100.
    •    Guam’s population is not projected to start falling until 2030 and is forecast to end the century with about 38% fewer people than it has now.
    •    
Natural decrease — when deaths exceed births — is expected to begin as early as 2027 in the U.S. Virgin Islands but not until 2089 in the Northern Mariana Islands. Such long-term declines are driven by a combination of falling fertility and persistent outmigration.

FERTILITY TRENDS AND PROJECTIONS

Fertility declined in all four territories over the past decade, but American Samoa and the Northern Mariana Islands experienced the steepest decreases.

In American Samoa, the total fertility rate (TFR) or the average number of children per woman was already on a downward trajectory in 2000, falling from 4.0 that year to 2.1 in 2026. In the Northern Mariana Islands, fertility did not begin to decline until 2016 but fell rapidly from 3.3 to 2.0 by 2026.

Guam experienced a 0.8 decrease in TFR over a 12-year period, from 3.2 in 2014 to 2.4 in 2026, and the U.S. Virgin Islands’ TFR dropped from 2.5 in 2007 to 1.9 in 2026.

The TFR level needed for long-term population replacement is 2.1. The U.S. Virgin Islands and the Northern Mariana Islands are currently below that level. American Samoa has hovered around the replacement level since 2021 but is projected to fall below it in 2029, and Guam is expected to do so in 2056.

MIGRATION TRENDS AND PROJECTIONS

More people have left than moved into each of the territories since 2000. In 2026, the net migration rate (the number of people entering minus those leaving per 1,000 residents) was -4.8 per thousand people in Guam; -5.4 in the U.S. Virgin Islands; -11.2 in the Northern Mariana Islands; and -25.1 in American Samoa.

Guam saw fewer people leave than enter the territory during the COVID 19 pandemic — which hit in March 2020 — due to travel restrictions. While net outmigration has started to pick up, it remains below pre-2020 levels.

In the U.S. Virgin Islands, net outmigration jumped sharply between the 2010 and 2020 Censuses, likely linked to the shutdown of a large oil refinery, the 2017 hurricanes Irma and Maria, and persistent economic and structural issues.

Across territories, projections assume that net outmigration will decline gradually and reach zero by 2100, helping maintain realistic long term population estimates for these small populations.

OTHER COUNTRIES

Today’s IDB release also updates estimates and projections of 21 countries: Armenia, Benin, Cyprus, the Democratic Republic of the Congo, Ghana, Indonesia, Iraq, Japan, Libya, Mali, Mozambique, Nepal, North Macedonia, South Sudan, Syria, Thailand, Turkey, Uganda, United States, Venezuela and Vietnam.

For some of the 21 countries, adjustments were incorporated for both crisis-related mortality and changes in the prevalence of HIV/AIDS.

For example, the 2023 earthquake in Turkey represented a substantial mortality shock, estimated at 53,000 deaths. This adjustment increased estimated 2023 deaths by nearly 7% from the previous year.

In Libya, catastrophic flooding in 2023 resulted in more than 13,000 deaths. Accounting for these deaths increased estimated deaths by 22% from 2022 to 2023 and contributed to a drop in life expectancy from 73.4 to 71.2 years.

AIDS-related mortality is incorporated in IDB population estimates and projections using specific guidelines because its age and sex specific patterns differ markedly from those in populations with less than 1% of HIV/AIDS prevalence rate.

In this update, the HIV/AIDS mortality component was removed from the projections of three countries because HIV prevalence fell below 1% since the last update. This happened for Benin, Mali and the Democratic Republic of the Congo.

(Sophia Magalona is a statistician and Rachel J. Bacon is a survey statistician and demographer at the Census Bureau.)