What Is the NIST Cybersecurity Framework?

The NIST Cybersecurity Framework (CSF) is a voluntary set of guidelines, best practices, and standards developed by the U.S. National Institute of Standards and Technology to help organizations manage and reduce cybersecurity risk. Originally designed for critical infrastructure sectors, it has since been widely adopted across industries of all sizes and types worldwide.

In 2024, NIST released CSF 2.0, expanding the framework beyond its original five functions to include a sixth: Govern. This update reflects the growing recognition that cybersecurity is a top-level organizational risk management concern, not just a technical function.

The Six Core Functions of CSF 2.0

The NIST CSF organizes security activities into six high-level functions, each representing a different phase of an organization's security posture:

1. Govern

Establish and maintain the policies, roles, and oversight processes needed to manage cybersecurity risk at the organizational level. This includes executive accountability, risk appetite definition, and supply chain risk management.

2. Identify

Develop an organizational understanding of cybersecurity risk to systems, people, assets, data, and capabilities. Key activities include asset management, business environment analysis, risk assessment, and governance.

3. Protect

Implement appropriate safeguards to limit or contain the impact of cybersecurity events. This covers access control, data security, training and awareness, and protective technologies like firewalls and endpoint protection.

4. Detect

Develop and implement activities to identify the occurrence of a cybersecurity event in a timely manner. Continuous monitoring, anomaly detection, and security event logging fall under this function.

5. Respond

Take action when a cybersecurity incident is detected. This includes incident response planning, communications, analysis, mitigation, and improvement activities.

6. Recover

Restore capabilities or services impaired by a cybersecurity incident. Recovery planning, improvements, and communications ensure the organization can return to normal operations and lessons are captured.

CSF Tiers: Measuring Your Maturity

The framework defines four Implementation Tiers that describe the sophistication and consistency of an organization's cybersecurity risk management practices:

  • Tier 1 – Partial: Ad hoc, reactive practices with limited awareness of cybersecurity risk.
  • Tier 2 – Risk Informed: Practices exist but are not formalized or organization-wide.
  • Tier 3 – Repeatable: Formally approved policies are implemented consistently across the organization.
  • Tier 4 – Adaptive: Cybersecurity practices are continuously improved based on lessons learned and threat intelligence.

The goal is not necessarily to reach Tier 4 everywhere — it is to achieve a tier appropriate to your risk profile and business context.

How to Use the CSF in Practice

  1. Create a Current Profile: Assess which CSF outcomes you currently achieve. Be honest — this is a baseline, not a report card.
  2. Create a Target Profile: Determine which outcomes you need to achieve based on your business risks, regulatory requirements, and risk appetite.
  3. Analyze the Gap: Compare current vs. target. Gaps become your security roadmap.
  4. Prioritize and Act: Tackle gaps in order of risk priority, not just ease of implementation.
  5. Repeat: The CSF is a living document. Reassess regularly — annually at minimum, or after significant changes to your environment.

CSF vs. ISO 27001: Which Should You Use?

Many organizations ask whether to follow the NIST CSF or pursue ISO 27001 certification. The short answer: they are complementary. The NIST CSF is a flexible risk management framework that is easier to adopt incrementally. ISO 27001 is an international certifiable standard with a formal audit process. Organizations that need to demonstrate compliance to partners or regulators often pursue ISO 27001 while using the NIST CSF as their internal management framework.

Getting Started

The NIST CSF is freely available at nist.gov/cyberframework. NIST also provides a reference tool that maps CSF subcategories to other standards including ISO 27001, COBIT, and CIS Controls — making it easier to leverage work you may have already done in another framework.

Whether you are building a security program from scratch or maturing an existing one, the NIST CSF provides a proven, structured language for managing cybersecurity risk that resonates with both technical teams and executive leadership.