Best Way to Structure an SSP for CMMC: Policies, Plans, and Procedures
Your System Security Plan (SSP) is the foundation of CMMC compliance. For CMMC Level 2, assessors rely on it to understand your environment, your controls, and how security is actually implemented. A weak or disorganized SSP is one of the most common reasons assessments stall or fail.
What an SSP Is (and Is Not)
An SSP documents how your system meets each NIST SP 800-171 requirement. It is not a policy binder and not a marketing document. If a control is not clearly described in the SSP, assessors may treat it as not implemented, even if the technology exists.
Core Sections Every CMMC SSP Should Include
A well-structured SSP typically includes:
System Overview
Purpose, boundaries, system architecture, and CUI description.System Scope
Identification of CUI assets, security protection assets, and risk-managed assets.Roles and Responsibilities
Who is responsible for security operations, administration, and oversight.Control Implementation Details
A control-by-control explanation of how each NIST SP 800-171 requirement is met, including tools, configurations, and processes.Network and Data Flow Diagrams
Clear visuals showing where CUI resides and how it moves through the environment.
How Policies, Plans, and Procedures Fit Together
Assessors expect alignment across documentation:
Policies explain what is required and why
Plans explain how requirements are met
Procedures explain step-by-step execution
If these documents conflict or fail to map back to SSP descriptions, credibility suffers.
Keep the SSP Assessment-Ready
An SSP is a living document. It should be:
Updated at least annually
Revised after system or control changes
Aligned to real-world operations, not idealized processes
Outdated SSPs are easy for assessors to spot.
Why Structure Matters
A clear SSP shortens assessments, reduces clarification requests, and lowers the risk of findings. Poor structure forces assessors to hunt for answers, which rarely works in your favor.
For CMMC, the SSP is not supporting documentation. It is the blueprint.