DemographyData storyIllinois, 2020–2025

The migration holding Illinois up.

Illinois keeps losing people to other states. Since 2022, a surge of international migration has been large enough to cover that domestic outflow—but the cushion narrowed sharply in the latest year.

By Kalaivani Chandramohan · July 18, 2026

−431,149
net domestic migration across five full estimate years
+313,184
net international migration over the same period
+109,564
total population change across the latest three years
−140,455
what those three years sum to without international migration

01 — The turn

Three gains followed two steep losses.

The newest Census vintage revises the whole series consistently. It shows Illinois returning to growth in 2022–23—not a missing decline year—and then posting its largest gain of the period in 2023–24.

Annual population change · people · July to July

Bars show annual change in Illinois’s resident population. Source: U.S. Census Bureau, Vintage 2025 state population estimates. The latest vintage supersedes earlier estimates and revises the full series.

02 — The balance sheet

Every year begins below zero.

Domestic migration was negative in every full estimate year. When total change crossed above zero, international migration was the only component large enough to do it; natural change helped, but never came close to covering the domestic loss by itself.

Domestic migration International migration Natural change
  1. 2020–21
    −108,364 domestic+11,432 intl. · +3,394 natural
    −91,994
  2. 2021–22
    −149,904 domestic+51,733 intl. · +2,671 natural
    −93,777
  3. 2022–23
    −79,784 domestic+94,146 intl. · +10,074 natural
    +23,812
  4. 2023–24
    −53,080 domestic+111,121 intl. · +11,941 natural
    +69,644
  5. 2024–25
    −40,017 domestic+44,752 intl. · +10,903 natural
    +16,108

Components do not sum exactly to total change because the Census estimate also includes a small residual. Bar lengths share a ±150,000-person scale. Values are from one consistent Vintage 2025 series.

03 — Scale changes the rank

Third-worst by count. Seventh-worst by rate.

Illinois’s 40,017-person domestic migration loss was smaller only than California’s and New York’s. Adjust for population, though, and six states lost residents faster. The problem remains large; the raw ranking makes it look more exceptional than it is.

Largest domestic losses

Net people, 2024–25

  1. California−229,077
  2. New York−137,586
  3. Illinois−40,017
  4. New Jersey−37,428
  5. Massachusetts−33,340
#3third-largest loss by raw count

Fastest domestic losses

Net migrants per 1,000 residents, 2024–25

  1. New York−6.88
  2. Hawaii−6.19
  3. Alaska−6.14
  4. California−5.82
  5. Massachusetts−4.67
  6. New Jersey−3.93
  7. Illinois−3.15
#7seventh-lowest rate among 50 states

Rankings exclude the District of Columbia and Puerto Rico. Rates use the Census Bureau’s own midperiod population denominator.

04 — County balance sheets

Cook lost 31,144 domestically—and still grew.

International migration and natural increase more than covered Cook County’s domestic loss. DuPage and Lake followed the same pattern, while McHenry and Kendall gained through every major component.

CountyDomesticInternationalNaturalTotal change
Cook−31,144+27,590+9,144+5,834
DuPage−5,854+4,583+2,873+1,647
Lake−3,176+2,670+1,330+849
McHenry+1,494+117+406+2,021
Kendall+1,276+291+782+2,345

Selected Illinois counties with the largest domestic outflows and inflows in 2024–25. Total change includes a small residual, so components may differ slightly from the displayed total.

The narrowing cushion
−59.7%

Illinois’s international-migration contribution fell from 111,121 in 2023–24 to 44,752 in 2024–25. Domestic losses also eased, but not enough to prevent total growth from falling 76.9%, to just 16,108.

The Census Bureau projects a further national slowdown in net international migration through July 2026. That is a national scenario, not an Illinois forecast; the next state estimates will show how much of the remaining cushion survived.