Revenue growth is currently supported by a 16.2% year-over-year increase in net interest income, though efficiency ratio volatility reaching as high as 56.0% in 2025Q4 highlights ongoing challenges in managing core operating costs.
| Metric | TTM | Dec'25 | Dec'24 | Dec'23 | Dec'22 | Dec'21 | Dec'20 | Dec'19 | Dec'18 | Dec'17 | Dec'16 | Dec'15 | Dec'14 | Dec'13 | Dec'12 | Dec'11 | Dec'10 | Dec'09 | Dec'08 | Dec'07 | Dec'06 | Dec'05 | Dec'04 | Dec'03 | Dec'02 | Dec'01 | Dec'00 | Dec'99 | Dec'98 | Dec'97 | Dec'96 |
|---|
| Net Interest Income | 64.9M | 62.54M | 55.84M | 57.94M | 60.48M | 52.7M | 50.35M | 49.45M | 48.23M | 45.92M | 42.8M | 41.34M | 41.18M | 39.4M | 42.98M | 41.7M | 40.01M | 38.27M | 35.78M | 28.01M | 24.98M | 23.91M | 23.36M | 23.53M | 22.91M | 21.54M | 20.35M | 19.22M | 13.32M | 12.2M | 11.74M |
| NII Growth % | 54.36% | 12.02% | -3.64% | -4.19% | 14.76% | 4.68% | 1.82% | 2.51% | 5.04% | 7.28% | 3.54% | 0.39% | 4.52% | -8.33% | 3.06% | 4.22% | 4.57% | 6.95% | 27.72% | 12.16% | 4.47% | 2.33% | -0.7% | 2.72% | 6.35% | 5.83% | 5.87% | 44.36% | 9.19% | 3.88% | 8.16% |
| Net Interest Margin % | 2.88% | 2.83% | 2.68% | 2.81% | 2.98% | 2.59% | 2.57% | 2.73% | 2.63% | 2.53% | 2.47% | 2.48% | 2.66% | 2.64% | 3% | 3.12% | 3.26% | 3.35% | 3.14% | 2.93% | 2.74% | 3.22% | 3.45% | 3.54% | 3.51% | 3.64% | 3.76% | 3.82% | 3.43% | 3.83% | 3.93% |
| Interest Income | 98.53M | 96.03M | 89.98M | 79.63M | 65.8M | 60.11M | 64.17M | 67.31M | 63.86M | 58.41M | 53.67M | 51.5M | 51.15M | 50.42M | 56.4M | 57.91M | 57.22M | 58.1M | 61.38M | 53.97M | 44.71M | 36.88M | 33.82M | 35.98M | 38.16M | 40.8M | 38.75M | 35.45M | 25.8M | 22.73M | 21.7M |
| Interest Expense | 33.63M | 33.49M | 34.14M | 21.69M | 5.32M | 7.41M | 13.82M | 17.86M | 15.63M | 12.49M | 10.87M | 10.16M | 9.97M | 11.02M | 13.42M | 16.2M | 17.2M | 19.84M | 25.61M | 25.96M | 19.73M | 12.97M | 10.46M | 12.45M | 15.26M | 19.26M | 18.4M | 16.22M | 12.48M | 10.53M | 9.96M |
| Loan Loss Provision | -456K | -563K | 1.88M | 629K | 483K | -518K | 1.67M | 30K | 978K | 253K | -135K | -2.77M | -668K | 1.11M | 2.3M | 3.83M | 4.86M | 6.09M | 9.5M | 1.21M | 682K | 777K | 735K | 1.46M | 1.02M | 770K | 565K | 509K | 321K | 386K | 500K |
| Non-Interest Income | 17.29M | 15.97M | 11.73M | 11.13M | 10.75M | 11.16M | 11.58M | 9.03M | 8.65M | 8.94M | 8.5M | 8.81M | 8.89M | 9.61M | 10.85M | 8.07M | 9.29M | 10.16M | 7.8M | 9.96M | -15.2M | -14.66M | -14.46M | -11.33M | -13.78M | -14.57M | -15.38M | -14.32M | -10.04M | -9.71M | -9.05M |
| Non-Interest Income % | 14.92% | 14.26% | 11.54% | 12.27% | 14.05% | 15.66% | 15.29% | 11.83% | 11.93% | 13.27% | 13.67% | 14.6% | 14.8% | 16.01% | 16.13% | 12.23% | 13.97% | 14.88% | 11.28% | 15.58% | -51.49% | -65.94% | -74.72% | -45.96% | -56.5% | -55.55% | -65.81% | -67.83% | -63.76% | -74.58% | -71.57% |
| Total Revenue | 115.82M | 112M | 101.71M | 90.76M | 76.55M | 71.28M | 75.75M | 76.34M | 72.52M | 67.35M | 62.17M | 60.31M | 60.04M | 60.03M | 67.25M | 65.97M | 66.51M | 68.26M | 69.19M | 63.93M | 29.51M | 22.23M | 19.36M | 24.65M | 24.38M | 26.23M | 23.37M | 21.12M | 15.75M | 13.02M | 12.65M |
| Revenue Growth % | 49.67% | 10.11% | 12.06% | 18.57% | 7.4% | -5.91% | -0.77% | 5.27% | 7.67% | 8.34% | 3.08% | 0.45% | 0.01% | -10.74% | 1.93% | -0.8% | -2.57% | -1.34% | 8.22% | 116.64% | 32.78% | 14.82% | -21.47% | 1.09% | -7.03% | 12.22% | 10.66% | 34.06% | 21% | 2.95% | 10.52% |
| Non-Interest Expense | 59.39M | 56.94M | 49.29M | 46.62M | 43.91M | 41.03M | 48.39M | 44.04M | 40.53M | 38.35M | 35.29M | 34.5M | 34.67M | 33.19M | 36.95M | 34.38M | 33.8M | 33.68M | 30.7M | 27.23M | 178K | -248K | -358K | 1.5M | -1.11M | -2.07M | -3.11M | -2.9M | -2.05M | -3M | -2.44M |
| Efficiency Ratio | 51.28% | 50.84% | 48.46% | 51.36% | 57.36% | 57.57% | 63.88% | 57.69% | 55.88% | 56.94% | 56.77% | 57.2% | 57.74% | 55.29% | 54.95% | 52.11% | 50.82% | 49.34% | 44.38% | 42.59% | 0.6% | -1.12% | -1.85% | 6.11% | -4.54% | -7.9% | -13.31% | -13.72% | -13.04% | -23.03% | -19.33% |
| Operating Income | 23.25M | 22.13M | 16.4M | 21.83M | 26.84M | 23.35M | 11.87M | 14.4M | 15.38M | 16.25M | 16.15M | 18.42M | 16.07M | 14.71M | 14.57M | 11.56M | 10.65M | 8.65M | 3.38M | 9.54M | 8.92M | 8.72M | 8.52M | 9.24M | 9.21M | 8.27M | 7.51M | 7.29M | 5M | 5.1M | 4.63M |
| Operating Margin % | 20.07% | 19.76% | 16.12% | 24.05% | 35.07% | 32.76% | 15.67% | 18.87% | 21.21% | 24.13% | 25.97% | 30.54% | 26.76% | 24.5% | 21.67% | 17.53% | 16.01% | 12.67% | 4.88% | 14.91% | 30.22% | 39.25% | 44.03% | 37.48% | 37.77% | 31.54% | 32.15% | 34.5% | 31.77% | 39.16% | 36.65% |
| Operating Income Growth % | - | 34.98% | -24.89% | -18.67% | 14.98% | 96.66% | -17.58% | -6.37% | -5.35% | 0.66% | -12.33% | 14.63% | 9.26% | 0.94% | 25.99% | 8.59% | 23.17% | 156.03% | -64.58% | 6.89% | 2.25% | 2.36% | -7.76% | 0.31% | 11.37% | 10.06% | 3.13% | 45.59% | -1.84% | 10.01% | 15.21% |
| Pretax Income | 25.24M | 24.12M | 16.4M | 21.83M | 26.84M | 23.35M | 11.87M | 14.4M | 15.38M | 16.25M | 16.15M | 18.42M | 16.07M | 14.71M | 14.57M | 11.56M | 10.65M | 8.65M | 3.38M | 9.54M | 8.92M | 8.72M | 8.52M | 9.24M | 9.21M | 8.27M | 7.51M | 7.29M | 5M | 5.1M | 4.63M |
| Pretax Margin % | 21.79% | 21.54% | 16.12% | 24.05% | 35.07% | 32.76% | 15.67% | 18.87% | 21.21% | 24.13% | 25.97% | 30.54% | 26.76% | 24.5% | 21.67% | 17.53% | 16.01% | 12.67% | 4.88% | 14.91% | 30.22% | 39.25% | 44.03% | 37.48% | 37.77% | 31.54% | 32.15% | 34.5% | 31.77% | 39.16% | 36.65% |
| Income Tax | 5.29M | 5.21M | 2.51M | 3.67M | 4.61M | 3.85M | 987K | 1.38M | 1.36M | 3.02M | 2.35M | 3.29M | 2.34M | 2.2M | 2.36M | 1.35M | 1.6M | 846K | -724K | 1.6M | 1.92M | 1.95M | 1.88M | 2.04M | 2.29M | 2.21M | 2.08M | 2.04M | 1.37M | 1.49M | 1.29M |
| Effective Tax Rate % | 20.94% | 21.61% | 15.3% | 16.79% | 17.16% | 16.48% | 8.31% | 9.58% | 8.86% | 18.56% | 14.54% | 17.85% | 14.59% | 14.93% | 16.22% | 11.71% | 15.06% | 9.78% | -21.44% | 16.83% | 21.51% | 22.33% | 22.03% | 22.02% | 24.82% | 26.66% | 27.73% | 28.04% | 27.39% | 29.22% | 27.94% |
| Net Income | 19.95M | 18.91M | 13.89M | 18.17M | 22.24M | 19.5M | 10.88M | 13.02M | 14.02M | 13.24M | 13.8M | 15.13M | 13.72M | 12.51M | 12.21M | 10.21M | 9.04M | 7.8M | 4.1M | 7.93M | 7M | 6.78M | 6.64M | 7.21M | 6.92M | 6.07M | 5.43M | 5.24M | 3.63M | 3.61M | 3.34M |
| Net Margin % | 17.23% | 16.88% | 13.66% | 20.02% | 29.05% | 27.36% | 14.37% | 17.06% | 19.33% | 19.65% | 22.2% | 25.09% | 22.86% | 20.84% | 18.15% | 15.48% | 13.6% | 11.43% | 5.93% | 12.4% | 23.72% | 30.49% | 34.33% | 29.23% | 28.4% | 23.13% | 23.24% | 24.83% | 23.07% | 27.72% | 26.41% |
| Net Income Growth % | 35.67% | 36.15% | -23.55% | -18.31% | 14.05% | 79.14% | -16.42% | -7.11% | 5.92% | -4.07% | -8.8% | 10.24% | 9.7% | 2.49% | 19.55% | 12.88% | 15.96% | 90.2% | -48.28% | 13.27% | 3.32% | 1.97% | -7.77% | 4.04% | 14.16% | 11.69% | 3.57% | 44.3% | 0.69% | 8.05% | 12.91% |
| Net Income (Continuing) | 19.95M | 18.91M | 13.89M | 18.17M | 22.24M | 19.5M | 10.88M | 13.02M | 14.02M | 13.24M | 13.8M | 15.13M | 13.72M | 12.51M | 12.21M | 10.21M | 9.04M | 7.8M | 4.1M | 7.93M | 7M | 6.78M | 6.64M | 7.21M | 6.92M | 6.07M | 5.43M | 5.24M | 3.63M | 3.61M | 3.34M |
| EPS (Diluted) | 2.72 | 2.56 | 1.86 | 2.40 | 2.91 | 2.45 | 1.34 | 1.61 | 1.74 | 1.65 | 1.73 | 1.90 | 1.74 | 1.59 | 1.56 | 1.31 | 1.17 | 1.01 | 0.53 | 1.11 | 0.98 | 1.04 | 1.02 | 1.24 | 1.10 | 1.07 | 0.96 | 1.04 | 0.29 | 0.95 | 0.89 |
| EPS Growth % | 37.56% | 37.63% | -22.5% | -17.53% | 18.78% | 82.84% | -16.77% | -7.47% | 5.45% | -4.62% | -8.95% | 9.2% | 9.43% | 1.92% | 19.08% | 11.97% | 15.84% | 90.57% | -52.25% | 13.27% | -5.77% | 1.96% | -17.74% | 12.73% | 2.8% | 11.46% | -7.69% | 258.62% | -69.47% | 6.74% | 1.14% |
| EPS (Basic) | - | 2.56 | 1.86 | 2.42 | 2.95 | 2.48 | 1.37 | 1.65 | 1.78 | 1.69 | 1.77 | 1.95 | 1.77 | 1.63 | 1.61 | 1.35 | 1.20 | 1.04 | 0.55 | 1.14 | 1.02 | 1.04 | 1.02 | 1.24 | 1.10 | 1.07 | 0.96 | 1.04 | 0.29 | 0.95 | 0.89 |
| Diluted Shares Outstanding | 7.34M | 7.38M | 7.48M | 7.58M | 7.65M | 7.97M | 8.11M | 8.1M | 8.07M | 8.03M | 8M | 7.95M | 7.91M | 7.86M | 7.8M | 7.77M | 7.73M | 7.7M | 7.68M | 7.17M | 7.13M | 6.54M | 6.48M | 5.81M | 6.31M | 5.69M | 5.65M | 5.06M | 3.87M | 3.8M | 3.76M |
Geographic and Liquidity Concentration
According to quarterly financial disclosures, ISBA achieved a 16.2% year-over-year growth in net interest income as of 2026Q1, signaling an effective repricing of the loan portfolio that appears to have outpaced the rising cost of local deposit funding within its core Central Michigan market footprint.
The consistent upward trajectory in NII suggests that the bank's localized relationship-based lending model provides sufficient pricing power to mitigate competitive pressures. Investors should monitor whether this growth can be sustained if deposit betas continue to climb, as the bank's reliance on a specific geographic corridor limits its ability to source lower-cost funding.
As reported in recent income statements, ISBA's net interest margin has remained largely range-bound between 0.6% and 0.8% over the last ten quarters, indicating that asset yield improvements are being largely offset by the rising cost of funds required to maintain its local deposit base.
The lack of meaningful margin expansion despite a higher interest rate environment suggests that the bank is facing significant pressure to retain core deposits. This stagnation warrants further investigation into the bank's deposit mix and whether the current branch-heavy model is becoming an inefficient vehicle for capital deployment.
Based on the provided financial data, ISBA's efficiency ratio fluctuated between 46.4% and 56.0% over the past two years, reflecting the inherent difficulty in managing a fixed-cost branch network while attempting to scale revenue in a highly concentrated and competitive regional banking market.
The variability in the efficiency ratio suggests that operating leverage is not yet optimized, as personnel and physical infrastructure costs appear to be scaling alongside revenue. This may indicate that the bank's traditional operating model is struggling to achieve the economies of scale necessary to drive significant margin improvement.
As evidenced by the shift from a $1.1M credit recovery in 2025Q2 to a $434K provision expense in 2025Q4, ISBA's provision for loan losses appears highly sensitive to management's periodic adjustments, which may be smoothing earnings rather than reflecting underlying changes in the agricultural loan portfolio's risk profile.
The erratic nature of provision expenses makes it difficult to assess the true health of the loan book, particularly given the bank's exposure to agricultural cycles. Investors should monitor whether these fluctuations are merely accounting adjustments or if they signal an emerging deterioration in the credit quality of the bank's core commercial and agricultural borrowers.
Based on reported figures, the bank's cash and equivalents position of $26M appears thin relative to its total asset base, raising concerns about its ability to manage unexpected deposit outflows or localized economic shocks within its seven-county Michigan footprint without resorting to more expensive wholesale funding.
This limited liquidity buffer, combined with a 100% geographic concentration, suggests a heightened risk profile that may not be fully captured by traditional valuation metrics. The bank's reliance on a narrow economic corridor warrants further investigation into its contingency funding plans and the potential impact of a regional downturn on its capital adequacy.
Quick answers to the most common questions about buying ISBA stock.
Isabella Bank Corporation (ISBA) is profitable, generating $18.9M in net income for the fiscal year ending 2025 with a net profit margin of 16.9%.
Isabella Bank Corporation (ISBA) reported an operating income of $22.1M, resulting in an operating profit margin of 19.8%. This margin reflects the operational efficiency of the business before interest and taxes.
Isabella Bank Corporation (ISBA) generated $79.1M in gross profit for the year, representing a gross profit margin of 70.6%. This demonstrates the company's core pricing power and production efficiency.