How many people are enrolled in Affordable Care Act plans in Illinois?
Refreshed annually
About 449K in 2026 (based on numbers from open enrollment period, which typically runs from early November to mid-January of the next year). That’s roughly 1 in 28 people, or about 3.5% of Illinois’s population. Illinois enrolls fewer residents than average: enrollment nationally averaged about 6.8%, and Illinois ranked 43rd among all states and Washington, DC.
449K
enrolled in qualified health plans (2026)
3.5%
of the states population enrolled in qualified health plans (2026)
In 2015, 2.7% of Illinois residents were enrolled in a qualified health plan through the Affordable Care Act (ACA), often called "Obamacare," both inside and outside of government. Enrollment rose to 3% in 2016; by the 2022 plan year, the first open enrollment period after the temporary expansion of ACA tax credits, it went up to 2.5%. The largest year-over-year increase occurred between 2024 and 2025, when enrollment grew by 0.5 percentage points, before peaking in 2025 at 3.7%.
In 2026, the share of Illinois's population enrolled in an ACA health plan was 3.2 percentage points lower than the national average.
Estimated share of the population enrolled in qualified health plans, by year
How many ACA enrollees in Illinois are new to the marketplace?
Enrollment changes reflect both new people buying ACA insurance for the first time and returning customers re-enrolling. In Illinois, re-enrollees made up a larger share of enrollment than new consumers starting in 2016 — a trend that continued through 2026. In 2026, re-enrollees accounted for 83.3% of enrollment, while new consumers made up 16.7%.
In 2026, 83.3% of ACA enrollees in Illinois were returning consumers, while 16.7% were new to the marketplace.
Share of qualified health plan enrollment in Illinois by new consumers and re-enrollees, 2015–2026
How many enrollees in Illinois receive ACA financial assistance?
There are several mechanisms that can lower the costs of ACA plans. Eligible individuals can apply for an Advance Premium Tax Credit (APTC) to reduce their monthly premiums; at year's end, their actual income determines whether they must repay excess credit or receive additional funds. There are also cost-sharing reductions that lower deductibles, copayments, out-of-pocket maximums, and coinsurance.
In Illinois, 85.3% of the people enrolled in qualified health plans received an APTC and/or cost-sharing reduction in 2026, 1.5 percentage points less than the national rate of 86.7%.
In 2026, 85.3% of ACA enrollees in Illinois received financial assistance.
Percentage of people enrolled in qualified health plans receiving APTC and/or CSRs, 2026
What is the average APTC in Illinois?
The average APTC in Illinois was $688, higher than the national average of $650 by $38, a 5.8% difference.
In 2026, Illinois's average APTC was 5.8% higher than the national average.
Average APTC among consumers receiving APTC, 2026
How much do APTCs reduce monthly premium costs in Illinois?
APTCs lowered the average 2026 premium in Illinois from $816 to $230, a reduction of $586, or roughly 71.8%.
In Illinois, 2026 APTCs reduced the statewide average premium from $816 to $230.
Average premium and average premium after APTC in Illinois, 2026
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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.