The National Institute of Standards and Technology (NIST) has published multiple cybersecurity frameworks, each designed for different purposes and audiences. With acronyms like CSF, SP 800-53, SP 800-171, AI RMF, and SSDF floating around, it's easy to get confused about which framework applies to your organization and why.
This guide breaks down the major NIST frameworks, explains their key differences, and helps you determine which ones your organization needs to implement.
Quick Reference: NIST Framework Comparison Table
| Framework | Purpose | Mandatory For | Control Count | Best For |
|---|---|---|---|---|
| NIST CSF 2.0 | Voluntary cybersecurity risk management | No one (voluntary) | 6 Functions, 22 Categories, 106 Subcategories | Any organization seeking structured security program |
| NIST SP 800-53 | Comprehensive security controls for federal systems | Federal agencies, FedRAMP | 1,000+ controls across 20 families | Federal agencies, cloud service providers to government |
| NIST SP 800-171 | Protecting Controlled Unclassified Information (CUI) | Defense contractors handling CUI | 110 requirements in 14 families | DoD contractors, CMMC compliance |
| NIST AI RMF | Managing AI-related risks | No one (voluntary) | 4 Functions: Govern, Map, Measure, Manage | Organizations developing or deploying AI systems |
| NIST SSDF | Secure software development practices | Federal software suppliers | 42 tasks across 19 practices | Software vendors selling to federal government |
NIST Cybersecurity Framework (CSF) 2.0
What It Is
The NIST Cybersecurity Framework is the most widely adopted NIST standard, used by 71% of organizations globally. Released in February 2024, CSF 2.0 represents a significant update to the original 2014 framework, adding a new "Govern" function and expanding applicability beyond critical infrastructure to all organizations.
The Six Core Functions
CSF 2.0 organizes cybersecurity activities into six core functions:
- GOVERN (New in 2.0): Establishes cybersecurity strategy, risk management, and accountability at the leadership level
- IDENTIFY: Understand your environment and manage cybersecurity risk to systems, assets, and data
- PROTECT: Implement safeguards to ensure delivery of critical services
- DETECT: Identify cybersecurity events through continuous monitoring
- RESPOND: Take action when a cybersecurity incident is detected
- RECOVER: Maintain resilience and restore capabilities after an incident
Key Changes from CSF 1.1 to 2.0
The biggest change is the addition of GOVERN as a standalone function. In version 1.1, governance was a small subcategory within IDENTIFY. Now it sits at the center of the framework, emphasizing that cybersecurity is an enterprise risk requiring C-suite ownership.
Other significant changes include:
- Supply Chain Risk Management moved from IDENTIFY to GOVERN
- Broader applicability beyond critical infrastructure to all organization types and sizes
- Enhanced implementation guidance with new profiles and tiers
- Improved alignment with other frameworks like ISO 27001 and COBIT
Who Should Use NIST CSF
- Organizations seeking a voluntary, flexible security framework
- Companies wanting to align with a widely recognized standard
- Businesses looking to reduce cyber insurance premiums (organizations using NIST CSF saw lower premium increases)
- Any organization wanting a structured approach to cybersecurity risk management
Implementation Complexity
Low to Medium - CSF is designed to be accessible and scalable. Organizations can start with basic controls and mature over time.
Typical Investment: $10,000-$50,000 for initial assessment and implementation Timeline: 2-4 months for initial implementation
NIST SP 800-53: Security and Privacy Controls
What It Is
NIST Special Publication 800-53 is the most comprehensive security control catalog published by NIST. Currently in Revision 5, it contains over 1,000 security and privacy controls organized into 20 control families.
The 20 Control Families
| Family | Abbreviation | Description |
|---|---|---|
| Access Control | AC | Managing who can access systems and data |
| Awareness and Training | AT | Security education programs |
| Audit and Accountability | AU | Logging and monitoring activities |
| Assessment, Authorization, and Monitoring | CA | Security assessments and authorizations |
| Configuration Management | CM | System configuration baselines |
| Contingency Planning | CP | Business continuity and disaster recovery |
| Identification and Authentication | IA | User identity verification |
| Incident Response | IR | Handling security incidents |
| Maintenance | MA | System maintenance procedures |
| Media Protection | MP | Protecting storage media |
| Physical and Environmental Protection | PE | Physical security controls |
| Planning | PL | Security planning documentation |
| Program Management | PM | Organizational security program |
| Personnel Security | PS | Employee security measures |
| PII Processing and Transparency | PT | Privacy controls (new in Rev 5) |
| Risk Assessment | RA | Identifying and evaluating risks |
| System and Services Acquisition | SA | Secure procurement practices |
| System and Communications Protection | SC | Protecting communications |
| System and Information Integrity | SI | Maintaining system integrity |
| Supply Chain Risk Management | SR | Managing supply chain risks |
Control Baselines
SP 800-53 defines three security baselines based on impact level:
- Low Baseline: ~130 controls for systems with limited impact if compromised
- Moderate Baseline: ~260 controls for systems with serious impact potential
- High Baseline: ~370 controls for systems with catastrophic impact potential
Who Must Comply
- Federal agencies: All federal information systems must implement 800-53 controls
- Federal contractors: Those operating federal systems or seeking FedRAMP authorization
- Cloud service providers: Required for FedRAMP certification
- State and local governments: Often adopt 800-53 voluntarily
Relationship to Other Frameworks
SP 800-53 is the foundation for many other NIST publications:
- SP 800-171 derives its 110 requirements from the 800-53 moderate baseline
- CMMC maps directly to 800-53 controls
- FedRAMP uses 800-53 as its control baseline
Implementation Complexity
High - This is the most comprehensive NIST framework. Full implementation typically requires dedicated compliance teams.
Typical Investment: $100,000-$500,000+ depending on baseline and organization size Timeline: 6-18 months for full implementation
NIST SP 800-171: Protecting CUI
What It Is
NIST Special Publication 800-171 focuses specifically on protecting Controlled Unclassified Information (CUI) in non-federal systems. It's essentially a streamlined version of SP 800-53 tailored for contractors and organizations handling sensitive government information outside federal systems.
The 110 Security Requirements
SP 800-171 contains 110 security requirements organized into 14 control families:
- Access Control (22 requirements)
- Awareness and Training (3 requirements)
- Audit and Accountability (9 requirements)
- Configuration Management (9 requirements)
- Identification and Authentication (11 requirements)
- Incident Response (3 requirements)
- Maintenance (6 requirements)
- Media Protection (9 requirements)
- Personnel Security (2 requirements)
- Physical Protection (6 requirements)
- Risk Assessment (3 requirements)
- Security Assessment (4 requirements)
- System and Communications Protection (16 requirements)
- System and Information Integrity (7 requirements)
What is Controlled Unclassified Information (CUI)?
CUI is government-created or owned information that requires safeguarding but isn't classified. Examples include:
- Export-controlled technical data
- Privacy information (PII)
- Proprietary business information
- Law enforcement sensitive information
- Critical infrastructure information
Who Must Comply
Compliance with SP 800-171 is mandatory for:
- Defense contractors and subcontractors handling CUI
- Organizations with DFARS clause 252.204-7012 in their contracts
- Any contractor storing, processing, or transmitting CUI
- Organizations pursuing CMMC certification
CMMC Connection
The Cybersecurity Maturity Model Certification (CMMC) builds directly on SP 800-171:
| CMMC Level | SP 800-171 Requirements | Assessment Type |
|---|---|---|
| Level 1 | 17 practices (subset) | Self-assessment |
| Level 2 | All 110 requirements | Third-party assessment |
| Level 3 | 110 + additional from 800-172 | Government assessment |
Key Differences from SP 800-53
| Aspect | SP 800-53 | SP 800-171 |
|---|---|---|
| Target Audience | Federal agencies | Non-federal contractors |
| Control Count | 1,000+ | 110 |
| Assessment | Third-party/government | Self-assessment (moving to third-party with CMMC) |
| Scope | All federal systems | Only systems handling CUI |
| Prescriptiveness | Very detailed | More flexible implementation |
Implementation Complexity
Medium to High - While simpler than 800-53, the 110 requirements still demand significant effort, especially for small contractors.
Typical Investment: $50,000-$200,000 for initial implementation Timeline: 3-12 months depending on current security posture
NIST AI Risk Management Framework (AI RMF)
What It Is
Released in January 2023, the AI Risk Management Framework provides guidance for managing risks associated with artificial intelligence systems. It addresses the unique challenges AI presents, including bias, transparency, security, and accountability.
The Four Core Functions
The AI RMF is organized around four functions:
- GOVERN: Establish policies, procedures, and accountability for AI risk management
- MAP: Understand AI system context, capabilities, and potential impacts
- MEASURE: Assess and track AI risks using appropriate methods and metrics
- MANAGE: Prioritize and act on AI risks based on assessment results
Characteristics of Trustworthy AI
The framework defines seven characteristics that trustworthy AI systems should exhibit:
- Valid and Reliable: AI produces accurate, consistent results
- Safe: AI doesn't endanger human life or property
- Secure and Resilient: AI resists attacks and recovers from failures
- Accountable and Transparent: AI decisions can be explained and traced
- Explainable and Interpretable: AI reasoning can be understood
- Privacy-Enhanced: AI protects personal information
- Fair with Harmful Bias Managed: AI treats all users equitably
Recent Updates (2024-2025)
NIST has expanded the AI RMF with several important additions:
- Generative AI Profile (July 2024): NIST-AI-600-1 addresses unique risks from generative AI including hallucinations, data poisoning, and prompt injection
- 2025 Updates: Enhanced focus on model provenance, data integrity, and third-party model assessment
- Cybersecurity AI Profile (in development): Guidance on using AI to enhance cybersecurity capabilities
Who Should Use AI RMF
- Organizations developing AI/ML systems
- Companies deploying AI in decision-making processes
- Regulated industries using AI (healthcare, finance, etc.)
- Any organization concerned about AI risks and governance
Implementation Complexity
Medium - The framework is principles-based rather than prescriptive, allowing flexible implementation.
Typical Investment: Varies widely based on AI usage complexity Timeline: Ongoing governance process rather than one-time implementation
NIST Secure Software Development Framework (SSDF)
What It Is
Published as SP 800-218, the SSDF provides a set of fundamental secure software development practices. It helps software producers reduce vulnerabilities and address the root causes of security weaknesses.
The Four Practice Groups
The SSDF organizes 42 tasks across 19 practices into four groups:
1. Prepare the Organization (PO) Getting people, processes, and technology ready for secure development:
- Define security requirements
- Implement supporting toolchains
- Define and use secure development criteria
- Implement and maintain secure environments
2. Protect the Software (PS) Securing the development environment and software artifacts:
- Protect all forms of code from unauthorized access and tampering
- Provide a mechanism for verifying software release integrity
- Archive and protect each software release
3. Produce Well-Secured Software (PW) Incorporating security into design and implementation:
- Design software to meet security requirements
- Review and analyze code for vulnerabilities
- Test code for security vulnerabilities
- Configure software to have secure settings by default
4. Respond to Vulnerabilities (RV) Managing vulnerabilities in released software:
- Identify and confirm vulnerabilities
- Assess and prioritize vulnerabilities
- Remediate vulnerabilities
- Perform root cause analysis
Compliance Requirements
SSDF compliance is mandatory for:
- Software producers selling to the U.S. federal government (per EO 14028)
- Organizations required to provide software attestation under OMB M-22-18
- Federal contractors developing custom software for agencies
Recent Updates
- SP 800-218A (2024): Extends SSDF to cover generative AI and foundation model development
- SP 800-218 Rev 1 (Draft, December 2025): Proposed updates for SSDF Version 1.2
Implementation Complexity
Medium - The framework is intentionally flexible, allowing organizations to adapt practices to their SDLC methodology.
Typical Investment: Integration into existing SDLC processes; varies based on maturity Timeline: 3-6 months for initial integration, ongoing improvement
How NIST Frameworks Relate to Each Other
Understanding the hierarchy and relationships between NIST frameworks helps organizations plan their compliance journey:
┌─────────────────────────────────────┐
│ NIST CSF 2.0 │
│ (High-level risk management) │
└──────────────┬──────────────────────┘
│
┌────────────────────┼────────────────────┐
│ │ │
▼ ▼ ▼
┌─────────────────┐ ┌─────────────────┐ ┌─────────────────┐
│ SP 800-53 │ │ AI RMF │ │ SSDF │
│ (Federal systems)│ │ (AI governance) │ │ (Secure SDLC) │
└────────┬────────┘ └─────────────────┘ └─────────────────┘
│
▼
┌─────────────────┐
│ SP 800-171 │
│ (CUI protection)│
└────────┬────────┘
│
▼
┌─────────────────┐
│ CMMC │
│ (DoD contracts) │
└─────────────────┘
Key Relationships
-
CSF provides the umbrella: CSF 2.0 is the high-level risk management framework that organizations use to structure their security program. The other frameworks provide detailed controls.
-
800-53 is the control catalog: When CSF says "Protect," 800-53 tells you exactly which controls to implement.
-
800-171 derives from 800-53: The 110 requirements in 800-171 are mapped directly to 800-53 moderate baseline controls.
-
CMMC enforces 800-171: CMMC adds third-party verification to 800-171 requirements for defense contractors.
-
AI RMF and SSDF are specialized: These frameworks address specific domains (AI and software development) and complement the broader cybersecurity frameworks.
Choosing the Right Framework for Your Organization
Decision Framework
Start with these questions:
-
Do you work with the federal government?
- Federal agency → SP 800-53
- Defense contractor with CUI → SP 800-171 + CMMC
- Federal software supplier → SSDF
- None of the above → Consider CSF
-
What are your compliance drivers?
- Regulatory requirements → Match framework to regulation
- Customer requirements → Ask what frameworks they recognize
- Cyber insurance → CSF is widely accepted
- Voluntary improvement → Start with CSF
-
Do you develop or deploy AI?
- Yes → Add AI RMF to your framework stack
-
Do you develop software?
- Software for federal use → SSDF required
- Commercial software → SSDF recommended
Common Framework Combinations
| Organization Type | Recommended Frameworks |
|---|---|
| Small business, no federal work | CSF 2.0 |
| Enterprise, no federal work | CSF 2.0 + ISO 27001 |
| Federal contractor (non-defense) | CSF 2.0 + SP 800-53 |
| Defense contractor with CUI | SP 800-171 + CMMC |
| Cloud service provider to government | SP 800-53 + FedRAMP |
| Software vendor to federal government | SSDF + relevant security framework |
| AI company | CSF 2.0 + AI RMF |
Implementation Roadmap
Phase 1: Assessment (Weeks 1-4)
- Identify applicable frameworks based on business requirements
- Conduct gap analysis against chosen framework(s)
- Document current security posture
- Prioritize remediation efforts
Phase 2: Planning (Weeks 5-8)
- Develop remediation roadmap
- Allocate resources and budget
- Define metrics and success criteria
- Establish governance structure
Phase 3: Implementation (Months 3-12)
- Implement controls in priority order
- Develop required policies and procedures
- Train staff on new requirements
- Document evidence of compliance
Phase 4: Validation (Ongoing)
- Conduct internal assessments
- Engage third-party assessors if required
- Address findings and gaps
- Maintain continuous compliance
Key Takeaways
-
NIST CSF 2.0 is the starting point for most organizations—it's voluntary, flexible, and widely recognized.
-
SP 800-53 is the comprehensive control catalog for federal systems and forms the basis for many other frameworks.
-
SP 800-171 is mandatory for contractors handling CUI and is the foundation for CMMC certification.
-
AI RMF addresses the unique risks of AI systems and should be adopted by organizations developing or deploying AI.
-
SSDF is required for software vendors selling to the federal government and provides valuable secure development guidance for all software producers.
-
These frameworks complement each other—most organizations will need to implement multiple NIST frameworks based on their specific requirements.
Get Expert Help with NIST Compliance
Navigating multiple NIST frameworks can be complex. Our compliance experts help organizations:
- Determine which frameworks apply to their business
- Conduct comprehensive gap assessments
- Develop practical implementation roadmaps
- Prepare for audits and certifications
- Maintain ongoing compliance
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