---
schema_version: "secwatch.filing_event.v1"
accession: "0000709283-25-000061"
form_type: "8-K"
ticker: "QMCO"
cik: "0000709283"
company_name: "QUANTUM CORP /DE/"
filed_at: "2025-10-06T23:59:59+00:00"
generated_at: "2026-05-17T04:40:11.690448+00:00"
event_type: "other_material"
sentiment: "negative"
materiality_score: 0.6
calibrated_materiality_score: 0.6
confidence: "high"
source: SEC EDGAR
---

# Quantum dismisses Grant Thornton, appoints CohnReznick as auditor; cites material weaknesses in internal controls

## Summary
- Audit Committee dismissed Grant Thornton as independent auditor effective Sept 30, 2025, after competitive process.
- Grant Thornton's reports for FY2025 and FY2024 included going-concern explanatory paragraph; no adverse opinions or disagreements.
- Material weaknesses in internal controls reported regarding controls environment, revenue recognition, manufacturing inventory, and warrants.
- Appointed CohnReznick as new auditor for FY2026, subject to standard client acceptance procedures.
- No prior consultations with CohnReznick on accounting matters during the past two fiscal years.

## SEC filing metadata
- accession: 0000709283-25-000061
- form_type: 8-K
- ticker: QMCO
- cik: 0000709283
- company_name: QUANTUM CORP /DE/
- filed_at: 2025-10-06T23:59:59+00:00
- event_type: other_material
- sentiment: negative
- materiality_score: 0.6
- calibrated_materiality_score: 0.6
- confidence: high
- sec_items: 4.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/709283/000070928325000061/0000709283-25-000061-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/709283/000070928325000061/qtm-20250930.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0000709283-25-000061
- JSON: https://secwatch.observer/filing/0000709283-25-000061.json
- Plain text: https://secwatch.observer/filing/0000709283-25-000061.txt

## Key facts
- Auditor Changes
  QUANTUM CORP /DE/ engaged CohnReznick LLP as its auditor.
  - Action: engagement
  - Auditor: CohnReznick LLP
  source text: Appointment of Independent Registered Public Accounting Firm As described above, the Audit Committee recently completed a competitive process to select an audit firm to serve as the Company’s independent registered public accounting firm for the fiscal year ending March 31, 2026, and related interim periods. On September 30, 2025 , the Company, at the recommendation of the Audit Committee, made the decision to select CohnReznick LLP (“CohnReznick”) as auditors for the Company for the fiscal year ending March 31, 2026, contingent upon the execution of an engagement letter following completion of CohnReznick’s standard client acceptance procedures.
  evidence_url: https://www.sec.gov/Archives/edgar/data/709283/000070928325000061/0000709283-25-000061-index.htm
- Auditor Changes
  QUANTUM CORP /DE/ dismissed Grant Thornton LLP as its auditor.
  - Action: dismissal
  - Auditor: Grant Thornton LLP
  - Successor: CohnReznick LLP
  source text: Dismissal of Independent Registered Public Accounting Firm The Audit Committee (the “Audit Committee”) of the Board of Directors of Quantum Corporation (the “Company”) conducted a competitive process to determine the Company’s independent registered public accounting firm for the fiscal year ending March 31, 2026. As a result of this process and following careful deliberation, on September 30, 2025 , the Audit Committee dismissed Grant Thornton LLP (“Grant Thornton”) as the Company's independent registered public accounting firm, effective as of that same date.
  evidence_url: https://www.sec.gov/Archives/edgar/data/709283/000070928325000061/0000709283-25-000061-index.htm

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