Protecting sensitive information has become a top priority for organizations working with the U.S. Department of Defense (DoD) and other federal agencies. Contractors that handle Controlled Unclassified Information (CUI) must follow strict cybersecurity requirements to reduce the risk of data breaches and cyber threats.
One of the most important security standards for protecting CUI is NIST SP 800-171: Protecting Controlled Unclassified Information in Nonfederal Systems and Organizations.
NIST SP 800-171 contains 110 security requirements designed to help organizations protect sensitive government information across their systems, networks, and processes.
What Is NIST SP 800-171?
NIST SP 800-171 is a cybersecurity framework created by the National Institute of Standards and Technology (NIST) to help non-federal organizations protect CUI.
It provides security requirements covering areas such as:
- Access control
- Incident response
- System protection
- Data security
- Risk management
- Employee awareness
For many DoD contractors, meeting NIST SP 800-171 requirements is a major part of preparing for CMMC 2.0 compliance.
Understanding the 110 Controls
The 110 requirements are organized into 14 security control families.
Each family focuses on a specific area of cybersecurity.
1. Access Control (AC) — 22 Requirements
Access control ensures that only authorized users can access sensitive information.
Key practices include:
- Limiting system access
- Managing user permissions
- Controlling remote access
- Restricting privileged accounts
- Monitoring user activity
Example:
A contractor should ensure employees only access CUI needed for their job responsibilities.
2. Awareness and Training (AT) — 3 Requirements
Organizations must educate employees about cybersecurity responsibilities.
Requirements include:
- Security awareness training
- Role-based security training
- Understanding cybersecurity risks
Example:
Employees should know how to recognize phishing attempts and protect sensitive data.
3. Audit and Accountability (AU) — 9 Requirements
This family focuses on tracking system activity.
Organizations should:
- Create audit logs
- Review security events
- Monitor user actions
- Protect audit information
Example:
Security teams should be able to identify who accessed sensitive files and when.
4. Configuration Management (CM) — 9 Requirements
Configuration management ensures systems are securely configured.
Includes:
- Maintaining system baselines
- Controlling system changes
- Removing unnecessary software
- Managing hardware and software inventory
Example:
Only approved applications should run on company systems.
5. Identification and Authentication (IA) — 11 Requirements
This protects systems by verifying user identity.
Controls include:
- Unique user accounts
- Strong passwords
- Multi-factor authentication (MFA)
- Authentication management
Example:
Users accessing CUI systems should use secure authentication methods.
6. Incident Response (IR) — 3 Requirements
Organizations must be prepared to handle cybersecurity incidents.
Requirements include:
- Detecting incidents
- Reporting security events
- Responding to threats
- Improving response processes
Example:
A company should have a documented plan for handling a cybersecurity breach.
7. Maintenance (MA) — 6 Requirements
Maintenance controls protect systems during repairs and updates.
Includes:
- Authorized maintenance activities
- Remote maintenance security
- Monitoring maintenance actions
Example:
Third-party technicians should not access systems without proper authorization.
8. Media Protection (MP) — 9 Requirements
This protects information stored on physical or digital media.
Includes:
- Protecting storage devices
- Encrypting sensitive data
- Controlling media access
- Secure disposal
Example:
USB devices containing sensitive information must be properly controlled.
9. Personnel Security (PS) — 2 Requirements
Personnel security focuses on protecting information through proper employee management.
Includes:
- Screening individuals
- Protecting access after role changes
Example:
Employees leaving an organization should immediately lose system access.
10. Physical Protection (PE) — 6 Requirements
Physical security protects facilities and equipment.
Controls include:
- Facility access restrictions
- Visitor management
- Monitoring physical areas
Example:
Server rooms should have controlled access.
11. Risk Assessment (RA) — 3 Requirements
Risk assessment identifies cybersecurity weaknesses.
Organizations should:
- Identify threats
- Analyze vulnerabilities
- Assess security risks
Example:
Regular security assessments help identify potential attack paths.
12. Security Assessment (CA) — 4 Requirements
Security assessments verify whether controls are working.
Includes:
- Testing security controls
- Reviewing policies
- Correcting weaknesses
Example:
Organizations should regularly evaluate their cybersecurity program.
13. System and Communications Protection (SC) — 16 Requirements
This protects data moving through networks and systems.
Includes:
- Encryption
- Secure communications
- Network protection
- Boundary defenses
Example:
Sensitive information should be encrypted during transmission.
14. System and Information Integrity (SI) — 7 Requirements
This focuses on detecting and preventing system issues.
Includes:
- Malware protection
- Vulnerability management
- Security updates
- Monitoring threats
Example:
Systems should receive regular security patches.
Why These 110 Controls Matter
The 110 requirements help organizations:
- Protect sensitive government information
- Reduce cyber risks
- Improve security maturity
- Meet DoD contract requirements
- Prepare for CMMC assessments
For defense contractors, compliance is not just about passing an assessment — it is about building a stronger cybersecurity foundation.
How to Prepare for NIST SP 800-171 Compliance
Organizations should follow a structured approach:
1. Identify CUI
Understand where sensitive information exists.
2. Perform a Gap Assessment
Compare current security practices against the 110 requirements.
3. Create a Plan of Action
Document weaknesses and remediation steps.
4. Implement Security Improvements
Improve policies, technology, and processes.
5. Maintain Continuous Compliance
Regular reviews and monitoring help maintain security readiness.
Conclusion
The 110 controls of NIST SP 800-171 provide a complete roadmap for protecting Controlled Unclassified Information.
For DoD contractors, understanding and implementing these requirements is a critical step toward achieving CMMC 2.0 compliance and maintaining eligibility for government contracts.
Strong cybersecurity is no longer optional — it is a foundation for doing business in today’s defense industry.