---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-24-083409"
form_type: "8-K"
ticker: "MKSI"
cik: "0001049502"
company_name: "MKS INC"
filed_at: "2024-04-01T23:59:59+00:00"
generated_at: "2026-06-04T04:19:09.404751+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.5
calibrated_materiality_score: 0.5
confidence: "high"
source: SEC EDGAR
---

# MKS Instruments CFO Seth Bagshaw retires; CEO John Lee assumes interim CFO role

## Summary
- Seth H. Bagshaw retired as EVP, CFO & Treasurer on April 1, 2024; remains special advisor until May 1, 2024.
- CEO John T.C. Lee assumes interim principal financial officer role; company continues search for permanent CFO.
- No material arrangements or family relationships disclosed in connection with Lee's interim appointment.

## SEC filing metadata
- accession: 0001193125-24-083409
- form_type: 8-K
- ticker: MKSI
- cik: 0001049502
- company_name: MKS INC
- filed_at: 2024-04-01T23:59:59+00:00
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.5
- calibrated_materiality_score: 0.5
- confidence: high
- sec_items: 5.02
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1049502/000119312524083409/0001193125-24-083409-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1049502/000119312524083409/d782021d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-24-083409
- JSON: https://secwatch.observer/filing/0001193125-24-083409.json
- Plain text: https://secwatch.observer/filing/0001193125-24-083409.txt

## Key facts
- Executive change
  John T.C. Lee was appointed as principal financial officer at MKS INC.
  - Action: assumed
  - Role: principal financial officer
  source text: Following Mr. Bagshaw’s retirement, on April 1, 2024, John T.C. Lee, President and Chief Executive Officer of the Company, assumed the role of principal financial officer of the Company on an interim basis while the Company continues its search for Mr. Bagshaw’s successor.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1049502/000119312524083409/0001193125-24-083409-index.htm
- Executive change
  Seth H. Bagshaw retired as Executive Vice President, Chief Financial Officer and Treasurer at MKS INC.
  - Action: retired
  - Role: Executive Vice President, Chief Financial Officer and Treasurer
  source text: As previously announced, on April 1, 2024, Seth H. Bagshaw retired as Executive Vice President, Chief Financial Officer and Treasurer of MKS Instruments, Inc. (the “Company”).
  evidence_url: https://www.sec.gov/Archives/edgar/data/1049502/000119312524083409/0001193125-24-083409-index.htm

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