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Profitability · Iowa

US Banks with Highest Net Interest Margin (NIM) in Iowa

Ranked among banks headquartered in Iowa. Re-ranked 1-100 within the state from the same national ranking population.

#1 Net Interest Margin (NIM): County Bank — 5.05% . Net Interest Margin (NIM) measures the spread between interest earned on assets and interest paid on liabilities — the core unit economics of a commercial bank.

Ranked: 197 banks with reported data Showing: Top 100 Source: FFIEC call reports (Q1 2026) What is this metric? See the US Banks with … glossary entry Go deeper: What Is Net Interest Margin? A Bank Profitability Guide
# Bank HQ US Banks with … Total Assets
1 County Bank Sigourney , IA 5.05% $230.4M
2 Heartland Bank Somers , IA 4.97% $264.8M
3 Bridge Community Bank Mount Vernon , IA 4.97% $148.5M
4 Security State Bank Algona , IA 4.85% $114.8M
5 Solon State Bank Solon , IA 4.81% $126.7M
6 Federation Bank Washington , IA 4.80% $151.2M
7 Iowa State Bank Clarksville , IA 4.80% $389.6M
8 Security Savings Bank Gowrie , IA 4.63% $198.8M
9 Libertyville Savings Bank Fairfield , IA 4.51% $393.9M
10 Cedar Valley Bank & Trust La Porte City , IA 4.45% $123.2M
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11 First Iowa State Bank Albia , IA 4.43% $404.3M
12 Farmers & Merchants Savings Bank Manchester , IA 4.43% $595.3M
13 Fnnb Bank Newton , IA 4.41% $104.6M
14 State Bank of Toledo, the Toledo , IA 4.40% $144.9M
15 Farmers Trust and Savings Bank Williamsburg , IA 4.32% $198.4M
16 Bank Plus Estherville , IA 4.30% $151.5M
17 First Bank Hampton Hampton , IA 4.29% $252.6M
18 Success Bank Bloomfield , IA 4.21% $267.1M
19 State Savings Bank Bedford , IA 4.19% $208.6M
20 Audubon State Bank Audubon , IA 4.16% $166.9M
21 American State Bank Osceola , IA 4.14% $352.0M
22 Bankiowa Cedar Rapids , IA 4.13% $836.5M
23 Citizens First National Bank Storm Lake , IA 4.12% $248.9M
24 Union State Bank Greenfield , IA 4.12% $168.8M
25 Iowa Falls State Bank Iowa Falls , IA 4.12% $204.2M
26 Liberty National Bank Sioux City , IA 4.12% $605.2M
27 Security State Bank Sutherland , IA 4.11% $485.3M
28 FNB Bank Fontanelle , IA 4.08% $277.4M
29 Cbi Bank & Trust Muscatine , IA 4.08% $1.66B
30 Peoples Bank Rock Valley , IA 4.08% $1.22B
31 Templeton Savings Bank Templeton , IA 4.06% $169.6M
32 Hiawatha Bank & Trust Company Hiawatha , IA 4.05% $156.7M
33 First Trust and Savings Bank Wheatland , IA 4.04% $314.9M
34 First State Bank Lynnville , IA 4.04% $390.1M
35 Rolling Hills Bank & Trust Atlantic , IA 4.04% $482.1M
36 Malvern Bank Malvern , IA 4.00% $252.3M
37 Houghton State Bank Red Oak , IA 3.99% $218.7M
38 State Savings Bank West Des Moines , IA 3.98% $327.5M
39 Glenwood State Bank Glenwood , IA 3.96% $362.1M
40 Premier Bank Rock Valley , IA 3.96% $847.9M
41 Ohnward Bank & Trust Cascade , IA 3.94% $489.2M
42 Westside State Bank Westside , IA 3.94% $259.4M
43 Twin Cedars Bank Bussey , IA 3.93% $117.2M
44 Gnb Bank Grundy Center , IA 3.91% $609.2M
45 Clear Lake Bank and Trust Company Clear Lake , IA 3.91% $647.3M
46 Midwest Heritage Bank, FSB West Des Moines , IA 3.89% $490.0M
47 Shelby County State Bank Harlan , IA 3.88% $540.0M
48 Decorah Bank and Trust Company Decorah , IA 3.88% $779.9M
49 Cedar Rapids Bank and Trust Company Cedar Rapids , IA 3.88% $2.87B
50 Bank Midwest Spirit Lake , IA 3.85% $1.32B
51 Raccoon Valley Bank Perry , IA 3.85% $489.9M
52 Farmers Trust & Savings Bank Earling , IA 3.85% $149.9M
53 Farmers Savings Bank Marshalltown , IA 3.85% $145.0M
54 First Community Bank Newell , IA 3.84% $121.0M
55 Community Bank Dunlap , IA 3.82% $139.7M
56 Exchange State Bank Ames , IA 3.82% $146.4M
57 Pilot Grove Savings Bank Pilot Grove , IA 3.81% $1.18B
58 First State Bank Stuart , IA 3.76% $130.3M
59 Union State Bank Winterset , IA 3.75% $146.2M
60 Liberty Trust & Savings Bank Durant , IA 3.75% $182.9M
61 Midstates Bank, N.A. Council Bluffs , IA 3.75% $631.4M
62 Hills Bank and Trust Company Hills , IA 3.74% $4.67B
63 First Bank Waverly , IA 3.72% $747.7M
64 Fidelity Bank & Trust Dubuque , IA 3.72% $2.58B
65 Manufacturers Bank & Trust Company Forest City , IA 3.71% $727.8M
66 Leighton State Bank Pella , IA 3.71% $293.4M
67 Marion County State Bank Pella , IA 3.69% $620.3M
68 South Story Bank & Trust Slater , IA 3.69% $607.3M
69 Mediapolis Savings Bank Mediapolis , IA 3.69% $272.6M
70 MidWestOne Bank Iowa City , IA 3.69% $6.25B
71 Visionbank of Iowa Ames , IA 3.68% $899.9M
72 Crawford County Trust and Savings Bank Denison , IA 3.68% $285.3M
73 Trubank Indianola , IA 3.68% $487.5M
74 Farmers State Bank Northwood , IA 3.67% $221.4M
75 Community State Bank Ankeny , IA 3.67% $1.74B
76 Waukon State Bank Waukon , IA 3.65% $450.2M
77 Farmers Trust & Savings Bank Buffalo Center , IA 3.65% $360.9M
78 Pinnacle Bank Marshalltown , IA 3.64% $313.3M
79 Dewitt Bank & Trust CO. De Witt , IA 3.64% $275.0M
80 Community Bank & Trust Company Muscatine , IA 3.64% $315.1M
81 Sibley State Bank Sibley , IA 3.63% $110.0M
82 Community Savings Bank Edgewood , IA 3.63% $616.1M
83 Bellevue State Bank Bellevue , IA 3.62% $181.0M
84 Connection Bank Fort Madison , IA 3.61% $543.5M
85 Earlham Savings Bank West Des Moines , IA 3.61% $383.1M
86 Iowa State Bank and Trust Company Fairfield , IA 3.61% $325.3M
87 Home State Bank Jefferson , IA 3.61% $485.7M
88 Iowa Trust and Savings Bank Centerville , IA 3.59% $211.4M
89 Cusb Bank Cresco , IA 3.59% $813.9M
90 Citizens State Bank Wyoming , IA 3.58% $136.8M
91 American Bank, N.A. Le Mars , IA 3.58% $546.5M
92 Farmers & Merchants State Bank Winterset , IA 3.57% $265.5M
93 Farmers State Bank Algona , IA 3.57% $157.4M
94 First Central State Bank De Witt , IA 3.57% $784.0M
95 Iowa State Bank Des Moines , IA 3.57% $464.3M
96 Primebank Le Mars , IA 3.57% $783.8M
97 Charter Bank Johnston , IA 3.57% $227.8M
98 West Iowa Bank West Bend , IA 3.56% $169.3M
99 Northwest Bank Spencer , IA 3.56% $2.97B
100 Bank Iowa West Des Moines , IA 3.55% $2.35B

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All data sourced from the most recent FFIEC call report filings, refreshed each quarter as new filings are processed. This leaderboard excludes banks with total assets under $100,000K to filter out anomalous micro-bank ratios. See /data-updates/ for the current data freshness window.

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