Walking into a CMMC assessment can feel a bit like preparing for a home inspection when you’re trying to sell your house. You know someone’s going to poke around in corners you forgot existed, and suddenly that loose doorknob you’ve been meaning to fix becomes a big deal. Defense contractors face similar anxiety when assessors show up to evaluate their cybersecurity practices.
The difference is that instead of checking for water damage and faulty wiring, CMMC assessors are hunting for gaps in how a company protects Controlled Unclassified Information (CUI). And unlike a home inspection where you might negotiate repairs after closing, failing a CMMC assessment can mean losing out on defense contracts altogether.
The Documentation Hunt Starts Before Anyone Shows Up
Here’s what trips up a lot of companies: auditors don’t just want to see that security controls exist. They want proof that these controls have been working consistently over time. That means documentation becomes absolutely critical.
Before the actual assessment begins, contractors need to have their System Security Plan (SSP) ready to go. This document isn’t just a formality—it’s the roadmap that tells assessors what security practices should be in place and how they’re implemented. When the SSP doesn’t match what’s actually happening in the organization, that’s when problems start piling up.
Assessors also look for evidence that policies aren’t just sitting in a binder somewhere collecting dust. They want to see logs, records, and proof of regular reviews. If a company claims they perform weekly vulnerability scans, there better be documentation showing those scans happened every single week, not just the month before the assessment.
Network Architecture Gets Put Under the Microscope
One of the first things assessors examine is how a company’s network is structured. They’re looking to see if CUI is properly separated from other data and whether the network boundaries are clearly defined and protected.
This is where a lot of contractors realize their network grew organically over the years without much planning. Maybe the accounting system connects to the same network as the engineering department handling sensitive defense data. That kind of setup raises red flags immediately.
Assessors check whether firewalls are configured correctly, if network segmentation actually exists, and whether remote access points are properly secured. They’re not just glancing at network diagrams—they’ll want to verify that what’s drawn on paper matches the real infrastructure. Working with experienced cmmc compliance consultants during the preparation phase helps contractors identify these network architecture issues before assessors find them during the formal review.
Access Controls Matter More Than Most People Think
Assessors spend considerable time evaluating who has access to what within an organization. The principle of least privilege isn’t just a nice idea—it’s a requirement. That means employees should only have access to the systems and data they actually need to do their jobs.
But here’s what happens in real life: someone gets hired, they’re given system access, and then they switch roles or take on additional responsibilities. Their access expands but never contracts. Before long, people have way more access than they need, and nobody’s quite sure who can see what anymore.
CMMC assessors will review user access lists, check how access requests are approved, and verify that access reviews happen regularly. They’re looking for orphaned accounts (former employees who still have active credentials), shared passwords, and accounts with excessive privileges. These issues are surprisingly common and surprisingly easy to fix with proper attention.
Incident Response Plans Get Tested
Having an incident response plan is one thing. Having a plan that people actually know how to execute is another. Assessors don’t just want to see a document titled “Incident Response Plan”—they want evidence that the organization has practiced using it.
This means looking for records of tabletop exercises, evidence of past incidents and how they were handled, and proof that the incident response team knows their roles. If a company can’t demonstrate that they’ve tested their plan or responded to actual security events in a documented way, that’s a problem.
The plan itself needs to cover specific scenarios: data breaches, malware infections, insider threats, and physical security incidents. Assessors check whether the plan includes clear procedures for containment, investigation, notification, and recovery. Vague statements about “handling security issues as they arise” won’t cut it.
Multi-Factor Authentication Isn’t Negotiable
This one seems straightforward, but assessors find gaps here all the time. Multi-factor authentication (MFA) needs to be implemented for remote access and privileged accounts at minimum. Some CMMC levels require it more broadly.
The trick is that MFA has to actually work and be consistently used. If there are backdoors or exceptions that let people bypass MFA, assessors will find them. They’ll test whether MFA can be disabled easily, check for accounts that were exempted without proper justification, and verify that MFA methods meet security standards (spoiler: SMS-based codes don’t count for higher CMMC levels).
Configuration Management Tells a Story
Assessors pay close attention to how systems are configured and whether those configurations are managed consistently. This includes baseline configurations for workstations and servers, change management processes, and documentation of any deviations from security standards.
They’re looking for evidence that when systems are deployed, they’re set up securely from the start—not just patched and secured later. Configuration management also ties into patch management, which is another area under heavy scrutiny. Assessors want to see that security patches are applied promptly and that there’s a system for tracking which systems are patched and which aren’t.
The People Problem Shows Up Everywhere
Technical controls get a lot of attention, but assessors also evaluate the human side of security. Security awareness training isn’t optional, and it can’t just be a one-time orientation video that new hires sleep through.
Assessors look for records showing that training happens regularly, covers relevant topics, and that employees are actually completing it. They might ask random employees basic security questions to gauge whether the training is effective. If people can’t explain basic concepts about handling CUI or recognizing phishing attempts, that reflects poorly on the organization’s overall security posture.
Physical Security Still Counts
It’s easy to forget about physical security when everyone’s focused on cyber threats, but assessors definitely check this area. They want to see that facilities where CUI is stored or processed have appropriate physical controls—locked doors, visitor logs, badge systems, and surveillance where needed.
This includes looking at how portable media is controlled, whether workstations lock automatically when unattended, and if sensitive documents are properly secured. A high-tech cybersecurity setup doesn’t mean much if someone can walk into the office and grab an unlocked laptop containing defense contract data.
Continuous Monitoring Proves Ongoing Vigilance
For higher CMMC levels, continuous monitoring becomes a key requirement. Assessors want to see that security isn’t just a point-in-time effort but an ongoing process. This means reviewing logs regularly, monitoring for anomalous behavior, and having systems that alert security teams to potential issues.
The assessment will include questions about how monitoring data is reviewed, who’s responsible for investigating alerts, and what actions get taken when suspicious activity is detected. Companies that treat monitoring as a “set it and forget it” checkbox exercise usually struggle here.
What Happens When Gaps Are Found
Most organizations discover some gaps during their assessment. The question is whether those gaps are minor issues that can be quickly remediated or fundamental problems that require major overhauls. Assessors document findings and categorize them by severity.
Minor issues might just need documentation updates or policy clarifications. Major gaps—especially those involving missing security controls or systemic problems—can result in a failed assessment. The good news is that contractors typically get a chance to remediate issues and come back for reassessment, but that process takes time and delays the ability to bid on contracts requiring certification.
The key to a successful CMMC assessment isn’t cramming at the last minute or trying to fake compliance. It’s building genuine security practices that protect sensitive information consistently over time. Assessors can tell the difference between a company that takes security seriously and one that’s just going through the motions to check a box. The evidence—or lack thereof—tells the whole story.
