The 100-Day Plan for Post-Merger Integration

The deal is signed. Day 1 is coming.What now?

Integration doesn’t start after Day 1 — it starts the moment you realize value isn’t created by signing a contract, but by making two businesses work together.

Here’s how to approach the critical first 100 days.

1. Focus on what matters most first

Not everything at once. Prioritize:

  • Functional (not systems) integration: Finance, HR, IT
  • Stabilizing key operations
  • Customer continuity
  • Leadership alignment

2. Assign a Program Lead who has actual authority

Post-merger integration is not a side project. It needs:

  • A dedicated leader
  • With C-level backing
  • And the time to do the job

3. Design your governance up front

Set up:

  • A steering committee
  • Decision forums
  • Escalation logic
  • Reporting cadence

…and stick to it.

4. Communication beats speculation

People hate uncertainty. Tell them what’s changing, what’s not, and when more info is coming.

Silence creates fear.
Structure creates trust.

5. Track and deliver early wins

Confidence builds when people see results.

Pick 1–2 visible improvements and make them real in the first 100 days.
It buys you credibility and momentum.