---
schema_version: "secwatch.filing_event.v1"
accession: "0001049521-23-000023"
form_type: "8-K"
ticker: "MRCY"
cik: "0001049521"
company_name: "MERCURY SYSTEMS INC"
filed_at: "2023-07-07T23:59:59+00:00"
generated_at: "2026-06-13T10:52:20.395133+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# Mercury Systems appoints JANA's Scott Ostfeld to Board; Ballhaus becomes Chairman

## Summary
- Appointed Scott Ostfeld (Managing Partner at JANA Partners, ~8% holder) as Class II director; JANA agreed to vote for Company nominees.
- William Ballhaus, Interim CEO, becomes Chairman; William O'Brien and Mary Louise Krakauer retire from Board at 2023 annual meeting.
- Board reduced by two seats to nine directors; five of nine appointed in past two years.
- Ostfeld to serve on Human Capital/Compensation and M&A/Finance Committees; involved in CEO search.
- JANA granted voting flexibility if ISS or Glass Lewis recommends against stock incentive plan amendment.

## SEC filing metadata
- accession: 0001049521-23-000023
- form_type: 8-K
- ticker: MRCY
- cik: 0001049521
- company_name: MERCURY SYSTEMS INC
- filed_at: 2023-07-07T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 1.01, 5.02, 7.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1049521/000104952123000023/0001049521-23-000023-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1049521/000104952123000023/mrcy-20230706.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001049521-23-000023
- JSON: https://secwatch.observer/filing/0001049521-23-000023.json
- Plain text: https://secwatch.observer/filing/0001049521-23-000023.txt

## Key facts
- Executive change
  Barry R. Nearhos was appointed as Lead Independent Director at MERCURY SYSTEMS INC.
  - Action: appointed
  - Role: Lead Independent Director
  source text: the Board appointed Barry R. Nearhos as lead independent director of the Board as of the Effective Time
  evidence_url: https://www.sec.gov/Archives/edgar/data/1049521/000104952123000023/0001049521-23-000023-index.htm
- Executive change
  Mary Louise Krakauer retired as Director at MERCURY SYSTEMS INC.
  - Action: retired
  - Role: Director
  source text: Mary Louise Krakauer informed the Board of her decision to retire from the Board as of the Effective Time
  evidence_url: https://www.sec.gov/Archives/edgar/data/1049521/000104952123000023/0001049521-23-000023-index.htm
- Executive change
  Scott Ostfeld was appointed as Director at MERCURY SYSTEMS INC.
  - Action: appointed
  - Role: Director
  source text: the Board has agreed to appoint Scott Ostfeld, Managing Partner and Portfolio Manager at JANA Partners, as a director in Class II of the Board for a term expiring at the 2023 Annual Meeting
  evidence_url: https://www.sec.gov/Archives/edgar/data/1049521/000104952123000023/0001049521-23-000023-index.htm
- Executive change
  William K. O'Brien retired as Director at MERCURY SYSTEMS INC.
  - Action: retired
  - Role: Director
  source text: the previously disclosed retirement of William K. O'Brien from the Board immediately prior to the commencement of the 2023 Annual Meeting
  evidence_url: https://www.sec.gov/Archives/edgar/data/1049521/000104952123000023/0001049521-23-000023-index.htm
- Executive change
  William L. Ballhaus was appointed as Chair of the Board at MERCURY SYSTEMS INC.
  - Action: appointed
  - Role: Chair of the Board
  source text: the Board has appointed William L. Ballhaus as Chair of the Board as of the Effective Time
  evidence_url: https://www.sec.gov/Archives/edgar/data/1049521/000104952123000023/0001049521-23-000023-index.htm
- Material Agreements
  MERCURY SYSTEMS INC entered into Voting Agreement with JANA Partners LLC (effective 2023-07-06).
  - Action: entry
  - Counterparty: JANA Partners LLC
  - Effective: 2023-07-06
  source text: On July 6, 2023, Mercury Systems, Inc. (the “Company”) entered into a Voting Agreement (the “Agreement”) with JANA Partners LLC (“JANA”).
  evidence_url: https://www.sec.gov/Archives/edgar/data/1049521/000104952123000023/0001049521-23-000023-index.htm

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