---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-22-304802"
form_type: "8-K"
ticker: "PSNL"
cik: "0001527753"
company_name: "Personalis, Inc."
filed_at: "2022-12-14T23:59:59+00:00"
generated_at: "2026-06-21T04:44:44.647138+00:00"
event_type: "leadership"
sentiment: "neutral"
materiality_score: 0.6
calibrated_materiality_score: 0.6
confidence: "high"
source: SEC EDGAR
---

# Personalis CEO John West retires; CFO Aaron Tachibana named interim CEO

## Summary
- CEO John West to retire as CEO and director effective Dec 31, 2022; will serve as advisor.
- CFO Aaron Tachibana appointed interim CEO; Christopher Hall named President, effective Dec 31, 2022.
- West receives 12 months base salary severance, COBRA subsidy, and 24-month equity acceleration.
- West to provide consulting services from Jan 4 to Jun 30, 2023 at $5,000/month; option exercise extended to Dec 31, 2023.
- Board initiates search for permanent CEO.

## SEC filing metadata
- accession: 0001193125-22-304802
- form_type: 8-K
- ticker: PSNL
- cik: 0001527753
- company_name: Personalis, Inc.
- filed_at: 2022-12-14T23:59:59+00:00
- event_type: leadership
- sentiment: neutral
- materiality_score: 0.6
- calibrated_materiality_score: 0.6
- confidence: high
- sec_items: 5.02, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1527753/000119312522304802/0001193125-22-304802-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1527753/000119312522304802/d429468d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-22-304802
- JSON: https://secwatch.observer/filing/0001193125-22-304802.json
- Plain text: https://secwatch.observer/filing/0001193125-22-304802.txt

## Key facts
- Executive change
  Christopher Hall was appointed as President at Personalis, Inc..
  - Action: appointed
  - Role: President
  source text: and Christopher Hall, the Company’s SVP and Head, Diagnostics Business, to serve as President, each effective December 31, 2022.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1527753/000119312522304802/0001193125-22-304802-index.htm
- Executive change
  John West retired as Chief Executive Officer and Director at Personalis, Inc..
  - Action: retired
  - Role: Chief Executive Officer and Director
  source text: On December 9, 2022, John West, co-founder, Chief Executive Officer and member of the board of directors (the “Board”) of Personalis, Inc. (the “Company”) notified the Company of his decision to retire as Chief Executive Officer and as a director of the Company, effective as of December 31, 2022.
  evidence_url: https://www.sec.gov/Archives/edgar/data/1527753/000119312522304802/0001193125-22-304802-index.htm
- Executive change
  Aaron Tachibana was appointed as interim Chief Executive Officer at Personalis, Inc..
  - Action: appointed
  - Role: interim Chief Executive Officer
  source text: The Board has appointed Aaron Tachibana, the Company’s Chief Financial Officer, to serve as interim Chief Executive Officer
  evidence_url: https://www.sec.gov/Archives/edgar/data/1527753/000119312522304802/0001193125-22-304802-index.htm

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