Cornerstone State Bank
Montgomery, Minnesota, Le Sueur County
$247M in total assets, the 2,770th largest of 4,309 US banks and 100th of 225 headquartered in Minnesota.
- FDIC certificate
- 21525
- Established
- 1974
- Owned by
- Cornerstone Bcorp Inc
- Primary regulator
- FDIC
- Website
- WWW.CORNERSTONESTATEBANK.COM
At a glance
Compared with 150 banks headquartered in Minnesota with $100 million to $1 billion in assets, as of June 30, 2026.
| Measure | This bank | Percentile | Peer range, middle 90% | Peer median |
|---|---|---|---|---|
| Total assets | $247M | 46% | $291M | |
| Loans | $152M | 45% | $184M | |
| Deposits | $224M | 47% | $249M | |
| Return on assets | 1.34% | 59% | 1.23% | |
| Net interest margin | 3.70% | 31% | 4.00% | |
| Efficiency ratio | 61.0% | 50% | 61.1% | |
| Equity to assets | 8.08% | 21% | 9.59% | |
| Loans to deposits | 68% | 21% | 83% |
Growth
Total assets grew 2.1% a year over the last 5 years and 4.0% a year over 10 years, without acquisitions.
Acquisitions
| Closed | Acquired bank | Assets at acquisition |
|---|---|---|
| Mar 2016 | Peoples State Bank of Madison Lake Madison Lake, MN | $25M |
Where they operate
7 branches in 5 counties.
Largest markets by deposits
| County | Deposits | Market share | Rank |
|---|---|---|---|
| Le Sueur County, MN | $86M | 10.6% | 4 of 8 |
| Scott County, MN | $45M | 1.6% | 13 of 16 |
| Sibley County, MN | $37M | 9.2% | 4 of 10 |
| Blue Earth County, MN | $37M | 1.4% | 15 of 17 |
| Carlton County, MN | $20M | 4.2% | 7 of 8 |
Deposits by branch from the FDIC Summary of Deposits, June 2026. Rank among all banks with branches in that county.
Branch history since 2016
Net gain of 2 branches since 2016 (5 to 7, +40.0%). 0 opened, 2 acquired, 0 closed or sold.
| Period | What happened | Opened or acquired | Closed or sold | Net change | Branches at end |
|---|---|---|---|---|---|
| Start of 2016 | Starting point | 5 | |||
| 2016 | Acquired Peoples State Bank of Madison Lake | 2 | 0 | +2 | 7 |
Balance sheet and earnings
Loans by type
| Type | Share | This bank | Peers |
|---|---|---|---|
| 1-4 family residential | 53% | 28% | |
| Commercial real estate | 18% | 25% | |
| Consumer | 7% | 4% | |
| Construction and land | 6% | 5% | |
| Multifamily | 5% | 4% | |
| Business (C&I) | 5% | 16% | |
| Farmland | 2% | 10% | |
| Agricultural | 1% | 8% | |
| Other | 2% | 1% |
Deposits by type
| Type | Share | This bank | Peers |
|---|---|---|---|
| Other interest-bearing | 57% | 49% | |
| Time deposits | 30% | 30% | |
| Noninterest-bearing | 14% | 21% |
Brokered deposits are 0.0% of deposits (peers 3.6%).
Return on assets
Trailing four quarters, with the peer median.
Credit and capital
| This bank | Peer median | |
|---|---|---|
| Noncurrent loans | 0.80% | 0.46% |
| Net charge-offs, annualized | -0.84% | 0.00% |
| Reserves to loans | 1.40% | 1.20% |
| Leverage ratio | 10.60% | 10.05% |
Noncurrent loans exclude government-guaranteed portions.
Related banks
Similar size in Minnesota
Largest competitors in Le Sueur County, MN
Figures as of June 30, 2026 from the bank's Call Report, FDIC structure and branch data, and the Federal Reserve. Short link: bankingstats.com/banks/cornerstone-state-bank-montgomery-mn