Arizona’s median age in 2020 of 38.9 was nearly identical to the national average, but the state’s increase in median age between 2010 and 2020 tied for the highest in the country. Arizona’s larger-than-average increase can be traced to strong net in-migration at early retirement and traditional retirement ages.

Arizona experienced a large increase between 2010 and 2020 in the number of residents between the ages of 55 and 79. This resulted from a combination of strong net in-migration and the aging of the large baby-boom generation from the 46-to-64 age group in 2010 into the 56-to-74 age group in 2020.

Despite this rapid growth in the older population, the share of Arizona’s populace in the 55+ age bracket was not that different from the national average in 2020. Arizona’s share of the population was less than the national average in the 55-to-64 age bracket and equal to the U.S. average in the 85-or-older age group. The share was above average in the 65-to-84 age bracket, particularly among those 70-to-79 years of age.

The share of the total population in Arizona was lower than the U.S. average in 2020 in each of the working-age groups from 25-to-64 years of age but above average among those 5-to-19 years of age. Between 2010 and 2020, the share decreased in Arizona in every age group younger than 55. Arizona’s numeric change in population between 2010 and 2020 was 759,485. The increase among those younger than 55 was only 135,054, just 18 percent of the overall increase.

Net natural increase (births minus deaths) accounted for 302,745 of the total increase in Arizona’s population between the 2010 and 2020 censuses. The remaining 456,740 increase resulted from net migration, including both international and domestic net migration. Those born from 1945 to 1965 — those of preretirement and retirement age between 2010 and 2020 — accounted for 56 percent of the state’s total net in-migration.

The median age in 2020 varied widely across Arizona’s counties. The figure was less than 35 in Coconino, Graham, and Greenlee counties but more than 50 in Gila, Mohave, La Paz, and Yavapai counties. In the state’s populous counties, the median was 37.2 in Maricopa, 40.4 in Pinal, and 41.2 in Pima.

Comparing household types in Arizona to the nation in 2020, Arizona had a somewhat lesser share of female householders with no spouse or partner present and slightly higher shares in each of the other three categories: married couples, cohabiting couples, and male householders with no spouse or partner present.

The homeownership rate in Arizona in 2020 was greater than the national average and fourth highest among 10 states in the West. Arizona’s rate did not drop as much as the national average between 2010 and 2020.