Is population growing or shrinking?

Refreshed annually
It grew by 35,400 between 2024 and 2025, the third-most among all counties in the US. Changes in population reflect birth and death rates, immigration patterns, regional shifts, and even the overall health of the economy. Maricopa County, AZ’s 0.76% annual increase was primarily driven by immigration to the state.
In the decade between 2015 and 2025, Maricopa County, AZ’s population grew by 12.3%.

+35.4K

population change (2024 to 2025)

+0.76%

percent change in population (2024 to 2025)
Since 2000, Maricopa County, AZ’s population increased 23 out of 25 years. The largest increase occurred between 2004 and 2005, when Maricopa County, AZ gained 144,400 residents. Its largest decline occurred between 2009 and 2010 when there were 194,700 fewer residents.

Maricopa County, AZ gained 35,400 residents between 2024 and 2025.

Annual population change, 2001–2025

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What contributes to population change in Maricopa County, AZ?

A county’s population is influenced by three factors:
  • Natural population change: If births outnumber deaths in a given year, natural population growth is positive. If deaths exceed births, it is negative. Between 2024 and 2025 natural population change was positive in Maricopa County, AZ, with births exceeding deaths by 11,900.
  • Immigration: international migration directly into or out of a county: If more people move in than move out, population change from immigration is positive. If more people move out than move in, it’s negative. Between 2024 to 2025, Maricopa County, AZ’s population change from immigration was positive with about 22,100 more people coming from another country directly to Maricopa County, AZ than leaving.
  • Domestic migration, moving between counties: Between 2024 to 2025, Maricopa County, AZ’s population change from domestic migration was positive with about 941 more people coming from any other county in the US.

Between 2024 and 2025, immigration was the primary driver of population growth in Maricopa County, AZ.

Components of population change from previous year, 2011–2025

How is the US population changing?

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Methodology

USAFacts standardizes data, in areas such as time and demographics, to make it easier to understand and compare.

Page sources

USAFacts endeavors to share the most up-to-date information available. We sourced the data on this page directly from government agencies; however, the intervals at which agencies publish updated data vary.