Population Growth
Pinal County, Arizona ranks fifth among U.S. counties in percent population growth from July 1, 2023, to July 1, 2024.[20] The county’s estimated population increased from 486,395 in 2023 to 513,862 in 2024, representing a 5.6% growth rate, far above the national average.[20] To understand what is driving this rapid expansion, it is necessary to decompose overall population change into its two main components: natural increase (births minus deaths) and net migration (domestic plus international).
Natural Increase (births and deaths)
A key consideration in evaluating natural increase is the county’s mortality pattern over time. In 2019, Pinal County recorded a crude death rate of 732.4 deaths per 100,000 residents, representing a typical pre-pandemic baseline.[19] Mortality then rose sharply during 2020 and 2021, reaching 1,124.0 deaths per 100,000 residents at the height of the COVID-19 pandemic.[19] By 2022, mortality had begun to decline, though it remained elevated relative to 2019 levels.[19] It is expected that as more data becomes available, the downward trend in mortality will continue and gradually return to levels similar to those observed before the pandemic.
Birth patterns show a more gradual change. Pinal County’s birth rate increased from 9.9 per 1,000 population in 2019 to 11.3 per 1,000 population in 2022.[19] Although this represents modest growth, the overall number of births only slightly outpaced the number of deaths during this period. Data from the U.S. Census Bureau’s population estimates confirm this: between April 1, 2020, and July 1, 2024, natural change contributed only 2,011 people to the county’s population growth.[21] This demonstrates that natural increase played a relatively minor role, as 2,011 people make up only a small fraction of the county’s total population increase of 87,855 during this period.[21]
Migration
In contrast, migration overwhelmingly drove Pinal County’s expansion. Between April 1, 2020, and July 1, 2024, the county experienced a net migration inflow of 86,082 people.[21] Domestic migration accounted for the vast majority of this increase, with 78,400 domestic in-migrants compared to 7,682 international migrants.[21] Net international migration includes the movement of both U.S.-born and foreign-born persons, movement between the United States and Puerto Rico, and the movement of Armed Forces personnel, however, it still represents only a small portion of total in-migration.[21] The data make clear that domestic migration, not natural increase and not international immigration, is the dominant force behind Pinal County’s rapid growth.
Age Structure
The county’s age structure provides further insight into these patterns and reinforces the interpretation that migration is the primary driver of population change. According to ACS estimates, 57.2% of Pinal County’s population in 2023 fell within the working-age range of 18–64, an increase from 56.9% in 2020.[22] Although the percentage change is small, the stability and slight rise of the working-age share is notable, especially in a high-growth area. Fast-growing counties often attract working-age adults and families who relocate from larger metropolitan regions, particularly those with higher housing costs or greater congestion. Pinal County’s age distribution aligns with this typical domestic in-migrant profile.
In addition, the data suggest that the county’s recent growth is not primarily driven by retirees or older adults, who would be reflected in a rising population of residents aged 65 and older. Instead, the presence of a slightly increasing working-age majority indicates that population change is shaped not only by the volume of net migration, but also by the demographic characteristics of those migrants. New arrivals to the county appear to be disproportionately young adults, middle-aged workers, and families.
This working-age dominance has several important implications for Pinal County’s development. A growing labor force can support employment expansion and economic productivity. The influx of families may increase demand for school enrollment, childcare services, and related infrastructure. Higher levels of domestic in-migration can also stimulate the housing market, contributing to rising demand and new residential construction. Over the long term, the county’s age structure will also shape future natural increase through population momentum, as a stable or growing share of adults in their childbearing years may help sustain birth levels even as mortality trends return to pre-pandemic patterns.
2010 census
As of the census of 2010, there were 375,770 people, 125,590 households, and 92,157 families living in the county. [14] The population density was 70.0 inhabitants per square mile (27.0 inhabitants/km2). There were 159,222 housing units at an average density of 29.7 units per square mile (11.5 units/km2). [15] The racial makeup of the county was 72.4% white, 5.6% American Indian, 4.6% black or African American, 1.7% Asian, 0.4% Pacific islander, 11.5% from other races, and 3.8% from two or more races. Those of Hispanic or Latino origin made up 28.5% of the population. [14] In terms of ancestry, 16.9% were German, 10.6% were Irish, 9.5% were English, and 2.8% were American. [16]
Of the 125,590 households, 37.0% had children under the age of 18 living with them, 55.8% were married couples living together, 11.7% had a female householder with no husband present, 26.6% were non-families, and 20.5% of households were made up of individuals. The average household size was 2.78 and the average family size was 3.21. The median age was 35.3 years. [14]
The median household income was $51,310 and the median family income was $56,299. Males had a median income of $45,082 versus $34,785 for females. The per capita income for the county was $21,716. About 10.1% of families and 13.5% of the population were below the poverty line, including 18.3% of those under age 18 and 7.6% of those age 65 or over. [17]
2000 census
As of the census of 2000, there were 179,727 people, 61,364 households, and 45,225 families living in the county. The population density was 34 inhabitants per square mile (13 inhabitants/km2). There were 81,154 housing units at an average density of 15 units per square mile (5.8 units/km2). The racial makeup of the county was 70.4% White, 2.8% Black or African American, 7.8% Native American, 0.6% Asian, 0.1% Pacific Islander, 15.7% from other races, and 2.7% from two or more races. 29.9% of the population were Hispanic or Latino of any race. 21.9% reported speaking Spanish at home, while 1.4% speak O'odham and <0.1% speak Apache. [18]
Of the 61,364 households 29.8% had children under the age of 18 living with them, 56.9% were married couples living together, 11.5% had a female householder with no husband present, and 26.3% were non-families. 21.1% of households were one person and 9.2% were one person aged 65 or older. The average household size was 2.68 and the average family size was 3.09.
The age distribution was 25.1% under the age of 18, 8.7% from 18 to 24, 27.3% from 25 to 44, 22.7% from 45 to 64, and 16.2% 65 or older. The median age was 37 years. For every 100 females, there were 114.2 males. For every 100 females age 18 and over, there were 117.0 males.
The median household income was $35,856 and the median family income was $39,548. Males had a median income of $31,544 versus $23,726 for females. The per capita income for the county was $16,025. About 12.1% of families and 16.9% of the population were below the poverty threshold, including 25.5% of those under age 18 and 8.7% of those age 65 or over.
United States
Arizona 
