Reimagining M&A change management: Why trust is the real accelerator in post-merger integration

Authors: Ami Louise Rich, Ashley Reichheld, Katie Impelman, Carrie Preston Lace, Emma Murry, and Sarah Kim

In the high-stakes, high-pressure world of mergers and acquisitions (M&A), change management has often followed a familiar pattern: leveraging communication plans, sentiment surveys, and periodic leadership updates. Yet, many leaders still can’t answer the critical question of whether employees are truly ready for the change ahead.

Traditionally, M&A change management has focused more on messaging than measuring what matters. Initiatives are frequently launched with unclear baselines for employee trust or readiness, leading to misaligned strategies and resistance.

At Deloitte, we’ve reimagined this model. Our approach helps clients integrate trust as a core accelerator of change readiness, uniting human-centered design with data-powered intelligence. The result? Measurable improvements in how people experience, interpret, and act during M&A transitions.

Employee trust is more than an abstract concept. It’s a predictive measure of performance. Workers who trust their organization are 2.3 times more likely to report working for a highly efficient organization.¹ That’s likely because high-trust workers are 1.8 times more motivated to work harder and 50% less likely to look for a new job.²

What employee trust means at Deloitte

Deloitte defines trust through four essential attributes:

• Humanity: Demonstrates empathy and kindness toward people
• Transparency: Openly shares information, motives, and choices in straightforward and plain language
• Capability: Creates quality experience and enables people to do their jobs well
• Reliability: Consistently delivers on promises and commitments

Together, these elements drive the perceptions that shape intent and behavior. Trust is measurable, and with TrustID®, organizations can assess baseline trust, segment by demographic, and intervene with precision.

Employee trust as a critical factor in M&A change management

In the context of a transaction, low trust among employees can quickly erode change readiness and put deal value at risk. Deloitte’s TrustID® workforce insights show that low-trust environments are consistently linked to lower adoption, weaker engagement, and higher friction during organizational change.³

When trust is low early in merger integration, organizations may face:

• Rising resistance and disengagement that weaken collaboration and integration;
• Delayed behavior change that slows adoption of new systems, structures, and leadership; and 
• Lasting damage to the company’s brand and employer value proposition, both internally and externally. 

Proactively building trust is more effective than trying to repair it once compromised. Companies should focus on sustaining and strengthening trust during the first 100 days of deal announcement, since missteps in this period can have enduring consequences for overall success.