---
schema_version: "secwatch.filing_event.v1"
accession: "0000842517-26-000224"
form_type: "8-K"
ticker: "ISBA"
cik: "0000842517"
company_name: "ISABELLA BANK CORP"
filed_at: "2026-09-28T20:30:15+00:00"
generated_at: "2026-10-12T13:36:39.146611+00:00"
event_type: "m_and_a"
sentiment: "neutral"
materiality_score: 0.3
calibrated_materiality_score: 0.3
confidence: "high"
source: SEC EDGAR
---

# Isabella Bank sets Oct 23 election deadline for Grand River merger; cash consideration ~$5.71/share

## Summary
- Grand River shareholders must submit Election Form to Continental Stock Transfer & Trust by 5:00 p.m. ET on Friday, October 23, 2026, to elect cash or Isabella common stock.
- Election materials mailed on/about September 28, 2026 to holders of record as of September 24, 2026.
- Each Grand River share converts into either cash (estimated ~$5.71 per share) or Isabella common stock at an estimated exchange ratio of 0.1413, subject to proration.
- Cash consideration pool is $18,262,391; exchange ratio uses 839,003 Isabella shares, based on assumed 9,136,529 Grand River shares outstanding at closing.
- Merger remains subject to regulatory approvals and customary closing conditions; parties expect to complete the deal in Q4 2026.

## SEC filing metadata
- accession: 0000842517-26-000224
- form_type: 8-K
- ticker: ISBA
- cik: 0000842517
- company_name: ISABELLA BANK CORP
- filed_at: 2026-09-28T20:30:15+00:00
- event_type: m_and_a
- sentiment: neutral
- materiality_score: 0.3
- calibrated_materiality_score: 0.3
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/842517/000084251726000224/0000842517-26-000224-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/842517/000084251726000224/isba-20260928.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000842517-26-000224
- JSON: https://secwatch.observer/filing/0000842517-26-000224.json
- Plain text: https://secwatch.observer/filing/0000842517-26-000224.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.