If you’ve started looking into security frameworks, you’ve probably run into three names over and over: NIST, CIS, and ISO 27001. They’re all respected, widely adopted, and designed to help organizations improve their security posture.
But they’re not interchangeable. Each framework has a different philosophy, structure, and ideal use case. Choosing the right one for your business depends on where you are today, where you’re trying to go, and what external requirements you might need to satisfy.
Here’s a practical comparison to help you decide.
The Three Frameworks at a Glance
CIS Controls (Center for Internet Security)
What it is: A prioritized set of security best practices organized into 18 control areas. Designed to be actionable and implementation-focused.
Philosophy: “Do these things, in roughly this order, and you’ll address the most common attack vectors.”
Structure:
- 18 Controls, each with specific safeguards
- Three Implementation Groups (IG1, IG2, IG3) based on organizational maturity
- IG1 is explicitly designed for small businesses with limited resources
Strengths:
- Highly practical and prescriptive; tells you what to do
- Prioritized; you know where to start
- Free to access
- IG1 is a realistic starting point for small businesses
Best for: Small to medium businesses that need clear, prioritized guidance and want to start with the fundamentals.
NIST Cybersecurity Framework (CSF)
What it is: A risk-based framework organized around five core functions: Identify, Protect, Detect, Respond, and Recover. Recently updated to version 2.0, which added Govern as a sixth function.
Philosophy: “Understand your risks and build capabilities across these functional areas.”
Structure:
- 6 Core Functions (Govern, Identify, Protect, Detect, Respond, Recover)
- Categories and subcategories within each function
- Framework Profiles let you define your target state
- Implementation Tiers (1–4) describe organizational maturity
Strengths:
- Flexible; adapts to any industry or organization size
- Risk-based; helps you prioritize based on your specific threat landscape
- Widely recognized by U.S. government and regulatory bodies
- Strong community of resources and implementation guides
Best for: Organizations that need a flexible, risk-based approach, especially those in regulated industries or working with government contracts.
ISO 27001
What it is: An international standard for information security management systems (ISMS). It defines requirements for establishing, implementing, maintaining, and continually improving an ISMS.
Philosophy: “Build a formal management system around information security with defined processes and continuous improvement.”
Structure:
- Clauses 4–10 define ISMS requirements (context, leadership, planning, support, operation, evaluation, improvement)
- Annex A provides 93 controls across 4 themes (organizational, people, physical, technological)
- Requires formal risk assessment and treatment processes
- Certifiable by third-party auditors
Strengths:
- Internationally recognized certification
- Comprehensive management system approach
- Demonstrates security commitment to customers and partners
- Structured continuous improvement process
Best for: Organizations that need formal certification, work with international clients, or want a comprehensive management system for long-term maturity.
Side-by-Side Comparison
| Factor | CIS Controls | NIST CSF | ISO 27001 |
|---|---|---|---|
| Cost | Free | Free | Standard must be purchased; certification costs |
| Prescriptiveness | High; tells you what to do | Moderate; guides what to address | Moderate; defines requirements |
| Certification | No formal certification | No formal certification | Yes; third-party auditable |
| Best starting point | IG1 (56 safeguards) | Framework Profile | Gap assessment |
| Ease of adoption | Easiest | Moderate | Most complex |
| International recognition | Good | Strong (U.S. especially) | Strongest internationally |
| Regulatory alignment | HIPAA, PCI (indirect) | HIPAA, CMMC, federal | GDPR, international contracts |
| Ideal org size | SMBs to mid-market | All sizes | Mid-market to enterprise |
How to Choose
Start with CIS If…
- You’re a small business getting started with formal security practices
- You want clear, actionable guidance without ambiguity
- You don’t have regulatory requirements mandating a specific framework
- You need something you can implement incrementally with limited staff
Start with NIST CSF If…
- You need a risk-based approach tailored to your specific environment
- You work with U.S. government agencies or federal contractors
- You’re in a regulated industry (healthcare, finance, critical infrastructure)
- You want a framework that scales as your organization grows
Start with ISO 27001 If…
- Your clients or partners require ISO certification
- You operate internationally and need globally recognized credentials
- You’re ready to invest in a formal management system
- You have the organizational maturity to support ongoing audit and review processes
They’re Not Mutually Exclusive
Here’s something that often gets overlooked: these frameworks aren’t competing standards. Many organizations use more than one.
A common approach:
- Start with CIS IG1 to get the fundamentals in place
- Map your progress to NIST CSF for a broader risk-based view
- Work toward ISO 27001 if certification becomes a business requirement
The controls in CIS map well to NIST CSF categories, and both align with ISO 27001 Annex A controls. Starting with one doesn’t lock you out of the others; it builds a foundation.
The Bottom Line
The best framework is the one you’ll actually implement. A perfectly chosen framework that sits on a shelf does nothing. A “good enough” framework that drives real action is infinitely more valuable.
For most small and medium businesses, CIS Controls (starting with IG1) is the most practical entry point. From there, you can layer on NIST CSF for risk management or pursue ISO 27001 if the business demands it.
If you’re unsure where to start or want help mapping your current security posture against a framework, an IT risk analysis can give you a clear baseline and a roadmap forward. That’s something we do regularly for businesses in exactly this position.
– Derek, Founder of DC Security Solutions.
DC Security Solutions provides IT risk analysis services including framework assessments against CIS, NIST CSF, and ISO 27001. Learn more →