100-Day Integration Management Office Post-Merger Integration Plan
Covers all IMO activities from pre-close through Day 100 (Integration Complete). Accompanying reports — Day 1 Checklist, Risk Register, Milestones, Next 14 Days, and Executive Dashboard — reflect progress as of T+30 (30 days post-close)
The IMO's 100-day plan ensures the teams move in concert with one another at a brisk tempo from pre-close to "integration complete."
In the two months before Day 1, the IMO establishes the governance model, decision rights, reporting cadence, and escalation paths needed to manage the integration effectively. After close, the IMO keeps the integration moving through regular workstream meetings, cross-functional dependency reviews, Steering Committee updates, and formal Day 30 and Day 100 gate reviews. These touchpoints provide visibility into progress and surface issues early,
From start to end, the IMO serves as the integration's central coordination point. It keeps each workstream aligned to the approved plan, manages cross-functional dependencies, and ensures issues are escalated and resolved before they impact timelines. Working closely with Finance, the IMO also tracks synergy commitments, validates results, and maintains accountability for every major integration objective.
As the integration progresses toward completion, the IMO shifts its focus from active coordination to a successful transition. The team closes remaining actions, captures lessons learned, updates the M&A playbook for future transactions, and transfers ongoing responsibilities to permanent business owners. Every remaining activity has a clear owner, completion date, and path to resolution.
For the IMO, the integration is complete only when the company no longer needs an IMO to keep the business moving forward as one. In this plan, that happens at Day 100. By then, every major milestone has been completed, governance has transitioned to the permanent organization, and ownership has shifted from the integration teams to the business.