American State Bank
Sioux Center, Iowa, Sioux County
$1.4B in total assets, the 784th largest of 4,309 US banks and 20th of 227 headquartered in Iowa.
- FDIC certificate
- 228
- Established
- 1913
- Owned by
- Ambank Co Inc
- Primary regulator
- FDIC
- Website
- www.ambankiowa.com
At a glance
Compared with 26 banks headquartered in Iowa with $1 billion to $10 billion in assets, as of June 30, 2026.
| Measure | This bank | Percentile | Peer range, middle 90% | Peer median |
|---|---|---|---|---|
| Total assets | $1.4B | 27% | $1.8B | |
| Loans | $1.4B | 54% | $1.3B | |
| Deposits | $1.2B | 27% | $1.5B | |
| Return on assets | 1.37% | 62% | 1.28% | |
| Net interest margin | 3.49% | 50% | 3.51% | |
| Efficiency ratio | 45.1% | 15% | 52.3% | |
| Equity to assets | 11.00% | 65% | 10.14% | |
| Loans to deposits | 111% | 98% | 90% |
Growth
Total assets grew 5.7% a year over the last 5 years and 6.1% a year over 10 years, without acquisitions.
Acquisitions
| Closed | Acquired bank | Assets at acquisition |
|---|---|---|
| Jul 2015 | Community Bank Alton, IA | $41M |
Where they operate
11 branches in 3 counties.
Largest markets by deposits
| County | Deposits | Market share | Rank |
|---|---|---|---|
| Sioux County, IA | $1.1B | 37.9% | 1 of 9 |
| Lincoln County, SD | $55M | 0.0% | 19 of 26 |
| Lyon County, IA | $53M | 6.9% | 6 of 6 |
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 3 branches since 2016 (8 to 11, +37.5%). 4 opened, 0 acquired, 1 closed or sold.
| Period | What happened | Opened or acquired | Closed or sold | Net change | Branches at end |
|---|---|---|---|---|---|
| Start of 2016 | Starting point | 8 | |||
| 2016 | Opened Sioux Falls | 1 | 0 | +1 | 9 |
| 2019 | Opened Sioux Center | 1 | 0 | +1 | 10 |
| 2021 | Opened Sioux Falls | 1 | 0 | +1 | 11 |
| 2022 | Closed Sioux Falls | 0 | 1 | −1 | 10 |
| 2023 | Opened Sioux Center | 1 | 0 | +1 | 11 |
Balance sheet and earnings
Loans by type
| Type | Share | This bank | Peers |
|---|---|---|---|
| Agricultural | 25% | 9% | |
| Commercial real estate | 18% | 22% | |
| Farmland | 18% | 12% | |
| Business (C&I) | 18% | 14% | |
| 1-4 family residential | 10% | 21% | |
| Multifamily | 6% | 11% | |
| Construction and land | 2% | 8% | |
| Consumer | 1% | 1% | |
| Other | 1% | 2% |
Deposits by type
| Type | Share | This bank | Peers |
|---|---|---|---|
| Other interest-bearing | 52% | 58% | |
| Time deposits | 37% | 27% | |
| Noninterest-bearing | 11% | 15% |
Brokered deposits are 6.4% of deposits (peers 4.8%).
Return on assets
Trailing four quarters, with the peer median.
Credit and capital
| This bank | Peer median | |
|---|---|---|
| Noncurrent loans | 0.65% | 0.28% |
| Net charge-offs, annualized | 0.06% | 0.01% |
| Reserves to loans | 1.35% | 1.19% |
| Leverage ratio | 10.81% | 10.19% |
Noncurrent loans exclude government-guaranteed portions.
Related banks
Similar size in Iowa
Largest competitors in Sioux County, IA
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/american-state-bank-sioux-center-ia