Illinois
Branch-office deposits reported to the FDIC Summary of Deposits survey by institutions operating in Illinois, June 30 of each survey year, 1994–2025. Dollar figures are the survey’s thousands-of-USD unit displayed as $B/$T.
Deposits, 1994–2025
Office-assigned deposits at branches in Illinois went from $186.74B in 1994 to $704.42B in 2025, nominal.
Source: FDIC Summary of Deposits FDIC Summary of Deposits, June 30 of each survey year, 1994-2025. State-level aggregate of branch rows. Methodology
Branches and institutions
The branch network in Illinois peaked at 5,046 offices in 2008; the 2025 survey counts 3,621. The institution count moved from 1,124 (1994) to 393 (2025).
Source: FDIC Summary of Deposits FDIC Summary of Deposits, June 30 of each survey year, 1994-2025. Methodology
Deposit concentration (HHI)
Statewide institution-share HHI: the sum of squared percent shares of each institution’s in-state deposits, 0–10,000. The shaded bands are the agencies’ 2010 Horizontal Merger Guidelines classification (section 5.3): unconcentrated below 1,500, moderately concentrated 1,500–2,500, highly concentrated above 2,500. The dashed line marks the 2023 Merger Guidelines threshold, under which markets with an HHI above 1,800 are highly concentrated (Guideline 1). Illinois’s HHI is 691 in 2025 (unconcentrated on the 2010 bands), against 137 in 1994 and a span peak of 743 in 2022. A statewide HHI is descriptive: merger review defines banking markets locally, not by state.
Source: FDIC Summary of Deposits | DOJ & FTC, Horizontal Merger Guidelines (2010), section 5.3 | DOJ & FTC, Merger Guidelines (2023), Guideline 1 HHI computed from FDIC Summary of Deposits branch rows, June 30 of each survey year, 1994-2025. Methodology
Largest institutions by in-state deposits, 2025
Branch rows grouped by FDIC certificate; names as reported to the survey. Share is of all SOD deposits booked in Illinois that year, the same shares the statewide HHI squares and sums.
| # | Institution | Deposits | Share | Branches |
|---|---|---|---|---|
| 1 | JPMorgan Chase Bank, National Association cert 628 | $120.48B | 17.10% | 263 |
| 2 | BMO Bank National Association cert 16571 | $106.59B | 15.13% | 178 |
| 3 | Bank of America, National Association cert 3510 | $46.53B | 6.61% | 120 |
| 4 | CIBC Bank USA cert 33306 | $44.92B | 6.38% | 19 |
| 5 | The Northern Trust Company cert 913 | $36.91B | 5.24% | 5 |
| 6 | Fifth Third Bank, National Association cert 6672 | $25.85B | 3.67% | 162 |
| 7 | PNC Bank, National Association cert 6384 | $23.10B | 3.28% | 148 |
| 8 | Old National Bank cert 3832 | $17.87B | 2.54% | 84 |
| 9 | U.S. Bank National Association cert 6548 | $17.12B | 2.43% | 155 |
| 10 | Citibank, National Association cert 7213 | $13.56B | 1.93% | 57 |
Source: FDIC Summary of Deposits FDIC Summary of Deposits, June 30, 2025. Deposits are office-assigned; an institution's internal allocation practices shape where its balances appear. Methodology
County concentration extremes, 2025
The most and least concentrated of Illinois’s 102 counties in the survey, by county-level deposit HHI. A county served by a single institution sits at the 10,000 ceiling by construction; thin county markets are the norm outside metros.
Most concentrated
| County | HHI | Inst. | Branches |
|---|---|---|---|
| Alexander | 10000 | 1 | 2 |
| Hardin | 10000 | 1 | 2 |
| Pope | 10000 | 1 | 1 |
| Edwards | 8327 | 2 | 2 |
| Cumberland | 7922 | 2 | 5 |
Least concentrated
| County | HHI | Inst. | Branches |
|---|---|---|---|
| St. Clair | 688 | 26 | 67 |
| DuPage | 932 | 45 | 250 |
| McHenry | 965 | 24 | 79 |
| Madison | 1063 | 25 | 77 |
| Winnebago | 1074 | 18 | 62 |
Source: FDIC Summary of Deposits FDIC Summary of Deposits, June 30, 2025. County HHIs use institution shares of summed branch deposits within the county. Methodology
Back to the national overview, or see the methodology for the survey definition, the HHI construction, and the office-assignment caveat.