Isabella Bank (ISBA) investor relations material

Strategic rationale and market expansion

• Acquisition expands presence in the vibrant and growing Grand Rapids, MI market, which is projected to outpace state averages in household income and population growth over the next five years.

• Grand River's community banking model and strong client relationships align with the acquirer's philosophy, supporting client retention and integration.

• The combined entity will add $434MM in net loans and $439MM in deposits, significantly increasing scale in West Michigan.

• Opportunity to deploy more liquidity, expand product offerings, and enhance wealth management and treasury services.

Transaction structure and terms

• 65% of Grand River shares will receive stock consideration, 35% will receive cash; shareholders can elect $5.72 per share in cash or 0.1415x shares of acquirer stock per Grand River share, subject to pro-ration.

• Aggregate consideration totals $54.6MM, or $5.98 per share on a blended basis, representing 123% of tangible book value.

• Transaction expected to close in Q4 2026, with a pay-to-trade ratio of 72% and a 3.4% premium on core deposits.

Financial impact and projections

• Projected EPS accretion of approximately 10.4% in 2027 and 11.0% in 2028, with high-teens IRR.

• Tangible book value dilution of 4.0% at closing, with an earnback period of 1.75 years using the crossover method.

• 35% cost savings identified, with $4.9MM in annual expense reductions fully phased in post-close.

• Pro forma capital ratios remain strong, with CET1 ratio at 10.4% at close and 11.5% by year-end 2027.