Why Healthcare M&A Requires Threat Modeling — Before the Deal Closes
Dec 19, 2025By Krishna Bala, CTO, ThreatModeler
Having spent a significant part of my career working in and alongside healthcare organizations, I’ve seen firsthand how growth through acquisition can accelerate innovation, expand access to care, and strengthen market position. I’ve also seen how it can quietly introduce risk at a scale few organizations fully appreciate.
In healthcare, acquisitions don’t just bring new revenue streams or patient populations. They bring entire application portfolios, each with its own architectures, integrations, security assumptions, and technical debt. When those systems handle PHI, claims data, clinical workflows, or identity, the stakes are exceptionally high.
Yet too often, security risk from acquired applications is discovered after the deal closes—during integration, or worse, after an incident.
That’s why I believe threat modeling must become a standard requirement in healthcare M&A, ideally during due diligence, and at a minimum as a non-negotiable integration gate.
M&A Is the Fastest Way to Inherit Risk
Healthcare security teams are already under pressure: legacy systems, regulatory complexity, understaffed teams, and an ever-expanding attack surface. M&A amplifies all of this overnight.
Every acquisition introduces:
- Applications built with different security standards
- Inconsistent identity and access controls
- Unknown data flows and third-party dependencies
- Latent vulnerabilities that haven’t been tested against today’s threat landscape
Once those systems are integrated—connected to enterprise identity, data lakes, EHRs, or cloud platforms—the parent organization becomes fully accountable for any breach that occurs.
Brand damage, the fines, the regulatory scrutiny, and patient trust all land in the same place.
Real-World Lessons from Healthcare (and Beyond)
We don’t have to speculate about this risk. It has already played out.
In healthcare, we’ve seen major incidents tied to acquired subsidiaries, where gaps in security visibility or controls became enterprise-wide problems after integration. In some cases, these incidents exposed millions of records and raised serious questions about how security oversight is applied across newly acquired entities.
Outside healthcare, the lesson is even clearer. A breach after the merger of two hospitality giants remains the canonical example of inherited risk: attackers were inside of the target company’s environment long before the acquisition. While the acquirer didn’t create the breach, they inherited it, along with the consequences.
The takeaway is simple: acquisitions don’t reset risk; they transfer it.
Why Due Diligence Needs Threat Models
Traditional M&A due diligence does a good job of evaluating financials, legal exposure, and operational fit. Security assessments, when they happen, are often high-level questionnaires or point-in-time reviews.
That’s not enough.
What’s missing is a clear, architectural understanding of how acquired applications can be attacked—and how those attacks would impact the combined organization.
Threat modeling provides precisely that.
By requiring threat models during due diligence, healthcare organizations can:
- Identify high-risk applications before integration
- Understand where PHI or sensitive workflows are most exposed
- Flag systems that require remediation before connectivity
- Provide defensible evidence of security diligence to boards and regulators
- Create a shared forum for security architects on both sides to assess cyber risk
When diligence access is limited, threat models should become a Day 0 integration requirement: no network connectivity, no SSO, and no data sharing until the portfolio is modeled against corporate standards.
Threat Modeling as an Integration Control
One of the biggest misconceptions I hear is threat modeling slows things down. In reality, the opposite is true.
When threat modeling is standardized and automated, it becomes a force multiplier:
- Integration teams know what’s safe to connect—and what isn’t
- Visual architectural threat models enable cross-functional collaboration among product managers, engineers, and security architects
- Security teams focus on remediation where it matters
- Leadership gains clarity instead of guesswork
- Post-integration surprises are dramatically reduced
At ThreatModeler, we see healthcare customers using threat modeling as a repeatable M&A control plane—enabling them to scale acquisitions without scaling breaches.
Why This Matters Even When M&A Spend Pauses
Ironically, periods when M&A activity slows are when this work matters most.
This is when organizations have the opportunity to:
- Normalize security standards across acquired portfolios
- Address inherited technical debt
- Build a repeatable process before the next deal wave
Threat modeling in this context isn’t a new spend. It’s risk containment. Preventing a single inherited vulnerability from becoming a reportable healthcare breach more than justifies the investment.
A Better Standard for Healthcare Growth
Healthcare will continue to grow through acquisition. That isn’t changing.
What can change is how we manage the risk that comes with it.
Requiring threat models, during due diligence or as a hard integration gate, isn’t just a security best practice. It’s a business imperative. It protects patients, preserves trust, and ensures that growth doesn’t come at the expense of resilience.
From my experience in healthcare, the organizations that get this right aren’t just more secure—they’re better prepared to grow.
If you want to see how your own teams can get earlier visibility into architecture and risk, connect with our team to learn more.