ISO 27001 vs NIST CSF: Which Is Right for You?
ISO 27001 and NIST CSF are two of the most respected security frameworks, but they serve different purposes. ISO 27001 is a certifiable international standard, while NIST CSF is a flexible framework for risk management. Understanding when to use each—or both—is key to building a strong security program.
Quick Comparison
| Factor | ISO 27001 | NIST CSF |
|---|---|---|
| Type | International standard (certifiable) | Framework (no certification) |
| Developed By | ISO/IEC | NIST (US Government) |
| Primary Focus | Information Security Management | Cybersecurity Risk Management |
| Controls | 93 controls (Annex A, 2022) | 6 Functions, 22 Categories, 106 Subcategories |
| Certification | Yes (3rd party audit) | No (self-assessment) |
| Cost | $35,000 - $100,000+ | $10,000 - $50,000 (implementation) |
| Timeline | 8-18 months | 3-12 months (flexible) |
| Geographic Focus | Global (especially EU) | US-focused (globally adopted) |
| Renewal | Annual surveillance, 3-year recertification | Continuous improvement (no renewal) |
Understanding the Key Differences
ISO 27001: Certifiable Standard
ISO 27001 is an international standard that specifies requirements for establishing, implementing, maintaining, and continually improving an Information Security Management System (ISMS). Certification is awarded after a successful third-party audit.
ISO 27001 Key Components:
- • Clauses 4-10: ISMS requirements (context, leadership, planning, etc.)
- • Annex A: 93 controls across 4 themes (Organizational, People, Physical, Technological)
- • Statement of Applicability (SoA): Document which controls apply
- • Risk Treatment Plan: How you address identified risks
NIST CSF: Flexible Framework
NIST Cybersecurity Framework (CSF) is a voluntary framework designed to help organizations manage cybersecurity risk. Updated to version 2.0 in 2024, it provides a common language for cybersecurity risk management without requiring certification.
NIST CSF 2.0 Core Functions:
- • Govern (New): Cybersecurity risk governance and strategy
- • Identify: Asset management, risk assessment, governance
- • Protect: Access control, awareness, data security
- • Detect: Anomaly detection, continuous monitoring
- • Respond: Response planning, communications, mitigation
- • Recover: Recovery planning, improvements, communications
Choose ISO 27001 If:
- ✓ You need a recognized certification for customers or partners
- ✓ You have international customers, especially in EU/UK
- ✓ Contracts or RFPs require ISO 27001 certification
- ✓ You want a structured, prescriptive approach
- ✓ You need to demonstrate compliance to auditors
- ✓ You're in regulated industries (finance, healthcare)
Choose NIST CSF If:
- ✓ You want flexibility to adapt to your organization's needs
- ✓ You're building a security program from scratch
- ✓ Budget or resources are limited
- ✓ You work with US federal government or critical infrastructure
- ✓ You want to benchmark and improve over time
- ✓ Formal certification isn't required by customers
Use BOTH If:
- ✓ You need ISO certification but want NIST's risk framework
- ✓ You serve both international and US government clients
- ✓ You want comprehensive coverage (ISMS + risk management)
- ✓ You're in critical infrastructure with global operations
- ✓ You want to use NIST CSF for ongoing improvement while maintaining ISO certification
Control Overlap: 80-85%
ISO 27001 and NIST CSF share significant overlap in their control objectives. Organizations implementing one framework are well-positioned to adopt the other.
Overlapping Areas
- • Access control and identity management
- • Risk assessment and treatment
- • Asset management and inventory
- • Incident response and recovery
- • Security awareness and training
- • Vendor and supply chain security
- • Continuous monitoring
- • Change management
Key Differences
- • ISO requires formal ISMS documentation
- • NIST CSF emphasizes maturity tiers (1-4)
- • ISO has specific audit requirements
- • NIST includes Govern function (CSF 2.0)
- • ISO certification is binary (pass/fail)
- • NIST allows gradual maturity improvement
NIST CSF Implementation Tiers
Tier 1: Partial
Ad hoc, reactive risk management. Limited awareness of cybersecurity risk.
Tier 2: Risk Informed
Risk management approved by leadership but not organization-wide.
Tier 3: Repeatable
Formal policies and procedures consistently implemented.
Tier 4: Adaptive
Continuous improvement, lessons learned integrated into practices.
Cost and Timeline Comparison
ISO 27001
- Implementation: $20,000 - $60,000
- Certification audit: $15,000 - $40,000
- Annual surveillance: $5,000 - $15,000
- Timeline: 8-18 months
- Maintenance: Ongoing ISMS management
NIST CSF
- Assessment: $5,000 - $20,000
- Implementation: $10,000 - $50,000
- No certification cost: Self-assessment
- Timeline: 3-12 months (flexible)
- Maintenance: Ongoing improvement
Using Both Frameworks Together
Many organizations use both frameworks together—ISO 27001 for certification and NIST CSF for ongoing risk management and improvement.
Mapping Between Frameworks
| NIST CSF Function | ISO 27001 Annex A Mapping |
|---|---|
| Govern | A.5 (Organizational Controls), Clauses 5-6 |
| Identify | A.5.9 (Asset Management), A.5.10 (Acceptable Use) |
| Protect | A.5.15-18 (Access), A.6 (People), A.7 (Physical), A.8 (Tech) |
| Detect | A.8.15-16 (Logging, Monitoring) |
| Respond | A.5.24-28 (Incident Management) |
| Recover | A.5.29-30 (Business Continuity) |
Common Questions
Can NIST CSF be certified?
No. NIST CSF is a voluntary framework with no formal certification. You can get third-party assessments, but there's no "NIST CSF certified" credential.
Is NIST CSF only for US organizations?
No. While developed by NIST (US), NIST CSF is globally adopted as a cybersecurity best practice framework. Many international organizations use it alongside ISO 27001.
Which should I implement first?
If you need certification for customers, start with ISO 27001. If you want to build a security program and improve maturity over time, start with NIST CSF. Many organizations implement both simultaneously.
Does ISO 27001 certification mean I'm NIST CSF compliant?
Largely yes. ISO 27001 certification demonstrates strong alignment with NIST CSF controls. You'd likely be at Tier 3 (Repeatable) or higher across most NIST CSF functions.
Implement ISO 27001 + NIST CSF efficiently
LowerPlane maps controls between ISO 27001 and NIST CSF, allowing you to implement both frameworks with shared evidence and reduce costs by 30%.