---
schema_version: "secwatch.filing_event.v1"
accession: "0001437749-23-006894"
form_type: "8-K"
ticker: "MBWM"
cik: "0001042729"
company_name: "MERCANTILE BANK CORP"
filed_at: "2023-03-16T23:59:59+00:00"
generated_at: "2026-06-18T00:07:30.327992+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.5
calibrated_materiality_score: 0.5
confidence: "high"
source: SEC EDGAR
---

# Mercantile Bank dismisses BDO USA, appoints Plante & Moran as auditor for 2023

## Summary
- Dismissed BDO USA as auditor; no disagreements or reportable events in FY2021-2022
- Appointed Plante & Moran as independent auditor for FY ending Dec 31, 2023
- BDO's reports for FY2021-2022 were unqualified with no adverse opinion
- No prior consultations with Plante & Moran on accounting or auditing matters

## SEC filing metadata
- accession: 0001437749-23-006894
- form_type: 8-K
- ticker: MBWM
- cik: 0001042729
- company_name: MERCANTILE BANK CORP
- filed_at: 2023-03-16T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.5
- calibrated_materiality_score: 0.5
- confidence: high
- sec_items: 4.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1042729/000143774923006894/0001437749-23-006894-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1042729/000143774923006894/mbwm20230316_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001437749-23-006894
- JSON: https://secwatch.observer/filing/0001437749-23-006894.json
- Plain text: https://secwatch.observer/filing/0001437749-23-006894.txt

## Key facts
- Auditor Changes
  MERCANTILE BANK CORP dismissed BDO USA, LLP as its auditor.
  - Action: dismissal
  - Auditor: BDO USA, LLP
  - Successor: Plante & Moran, PLLC
  source text: On the same date, the Audit Committee dismissed BDO USA, LLP (“BDO”) as our independent registered public accounting firm.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1042729/000143774923006894/0001437749-23-006894-index.htm
- Auditor Changes
  MERCANTILE BANK CORP engaged Plante & Moran, PLLC as its auditor.
  - Action: engagement
  - Auditor: Plante & Moran, PLLC
  source text: appointed Plante & Moran, PLLC (“Plante & Moran”) as our independent registered public accounting firm for the fiscal year ending December 31, 2023, subject to normal and customary client engagement procedures.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1042729/000143774923006894/0001437749-23-006894-index.htm

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