If your organization is pursuing an Authority to Operate (ATO) under the FedRAMP program, writing and maintaining a strong System Security Plan (SSP) is one of the most important parts of your compliance journey. 

The SSP outlines how your cloud service offering protects federal information, satisfies control requirements, and meets the rigorous expectations of the Federal Risk and Authorization Management Program.

This guide will walk you through what a FedRAMP SSP is, what it needs to include, and how to ensure your documentation aligns with the latest FedRAMP 20x program updates. 

What is a FedRAMP SSP?

A FedRAMP System Security Plan is a document that describes how a cloud service provider (CSP) secures its cloud service offering (CSO). It explains the system components involved, how the information system is structured, how federal data flows to, from, and within the system, and how the organization has implemented each of the required FedRAMP requirements.

The SSP is part of your overall security authorization package and is reviewed closely by Third Party Assessment Organizations (3PAOs), federal agencies, and the FedRAMP Program Management Office (PMO). It demonstrates your understanding of the FedRAMP security requirements and your ability to protect federal information in a cloud computing environment.

While not required for FedRAMP 20x, an SSP is still required for the Li-SaaS, Low, Moderate, and High baselines. This key document acts as a comprehensive reference point that supports security assessment activities and drives the Plan of Action and Milestones (POA&M) process during remediation. Let’s take a closer look at what must be included in this document.

What to include in a FedRAMP System Security Plan

FedRAMP provides one SSP template that must be used for any of the four baselines (LI-SaaS, Low, Moderate, and High). 

This FedRAMP official template is aligned with NIST SP 800-18 and NIST SP 800-53, and includes dozens of required sections. These sections walk assessors through your environment, explain how controls are implemented, and establish clear lines of security responsibility.

Here are the key areas to focus on:

1. System identification and overview

Start by identifying the cloud system, its mission, and what types of federal information it handles. Include the FIPS 199 impact level (Low, Moderate, or High), the deployment model (SaaS, PaaS, IaaS), and a brief summary of what the CSO does.

You should also explain who the information system owner and information security officer are, where the system is hosted, and how it supports federal agencies that will rely on your service.

2. System environment

Detail the cloud architecture, network architecture, infrastructure provider, operating system, and application stack. Describe any virtualization layers, encryption tools, or boundary protections that support information security within the system.

Be sure to explain the interfaces between internal and external systems, especially if other federal or non-federal systems exchange data with yours.

3. System boundaries and interconnections

Define your authorization boundary, listing every in-scope asset, tool, and third-party service. Visual diagrams help clarify how your infrastructure is set up, data flows through your environment, and how those flows are secured.

Also document any interconnections with external systems. This includes APIs, partner integrations, third-party connections, or shared services, and should describe the data type flowing between systems, authentication, and access control mechanisms in place for each.

4. Control implementation summary

This is the most detailed part of the SSP. You’ll walk through each required FedRAMP control, explain how it’s implemented, and identify whether the control is inherited from your infrastructure provider or handled by your organization.

Include:

• A description of how the control is met
• The specific technologies or procedures used
• Who is responsible for each control
• References to relevant policies, procedures, or configurations

This section may include hundreds of entries, depending on your baseline. Using a workbook or GRC tool to manage this content can help keep it organized.

5. Security control inheritance and shared responsibilities

Clearly outline which FedRAMP controls are inherited from your IaaS/PaaS provider and which are your responsibility. Include a shared responsibility matrix (SRM) or customer responsibility matrix (CRM) to show who manages what.

The FedRAMP PMO expects a high level of clarity here, especially for Moderate and High baseline systems.

6. Continuous monitoring and maintenance

Explain how you monitor the effectiveness of your FedRAMP controls and respond to changes or threats over time. This includes:

• Regular vulnerability scans and penetration testing
• Ongoing risk assessments
• Monitoring tools and alerts
• Control reviews and audits
• Configuration management practices

7. Required Appendices

In addition to the main body of the SSP, FedRAMP requires cloud service providers to include a set of structured appendices that provide supporting documentation, detailed evidence, and required worksheets. These appendices help assessors verify your implementation, evaluate risks, and validate compliance with FedRAMP’s baseline expectations.

Each appendix serves a distinct purpose, whether it’s clarifying your control implementation (Appendix A), documenting digital identity requirements (Appendix E), or providing plans for contingency (Appendix G), incident response (Appendix I), and continuous monitoring (Appendix N).

These appendices are not optional. They are a formal part of the FedRAMP security authorization package and must be submitted in full for an ATO request to proceed.

What are the SSP Appendices?

A complete FedRAMP SSP must include a series of required appendices that provide critical documentation supporting your control implementation, risk posture, and operational practices. Each appendix serves a distinct purpose and helps assessors, agencies, and the FedRAMP PMO evaluate your readiness for authorization.

Below is a breakdown of each required appendix and what it should include:

Appendix A: FedRAMP Security Controls

Select the appropriate baseline template (LI–SaaS, Low, Moderate, or High) from the FedRAMP Documents and Templates webpage and maintain your control implementation descriptions in a separate document. For each control, describe how it is implemented, the technologies or processes involved, and who is responsible for managing it. 

Since this appendix essentially functions as the heart of your SSP, we’lll discuss how to write it in more depth below.

Appendix B: Related Acronyms

List any CSO- or CSP-specific acronyms used throughout the SSP. This is included as a table within the SSP document, not a separate file, and ensures clarity and consistency for reviewers unfamiliar with your internal terminology.

Appendix C: Security Policies and Procedures

Provide the underlying policies and procedures (P&Ps) that support your control implementations. These are required by each “dash one” control (e.g., AC-1, IR-1) and demonstrate how your organization defines and enforces security practices. Whether you choose a centralized or control-family-specific format, make sure P&Ps are easy to navigate and aligned with your SSP narratives.

Appendix D: User Guide

Document how federal agency customers will interact with your system. This may include instructions for using a self-service portal, accessing documentation, or requesting support. A dynamic web-based guide is acceptable as long as the information is accessible and regularly maintained.

Appendix E: Digital Identity Worksheet

Identify the digital identity assurance level your system must meet based on NIST SP 800-63. This worksheet captures your system’s authentication requirements and is included as a table within the SSP itself.

Appendix F: Rules of Behavior (RoB)

Establish expectations and acceptable use guidelines for all internal and external users of the CSO. FedRAMP provides a RoB template with examples of rules of behavior  for privileged and non-privileged users. These examples must be tailored to reflect your actual user base and security requirements.

Appendix G: Information System Contingency Plan (ISCP)

FedRAMP provides an Information System Contingency Plan (ISCP) template. Use the FedRAMP-provided ISCP template to document your organization’s contingency planning strategy. This includes backup, recovery, business continuity, and how your system responds to service interruptions.

Appendix H: Configuration Management Plan (CMP)

Develop a Configuration Management Plan in alignment with NIST SP 800-128. While FedRAMP does not offer a template, Appendix D of 800-128 includes a helpful sample outline.

Appendix I: Incident Response Plan (IRP)

Create an IRP following the guidance in NIST SP 800-61. This appendix should describe how your organization detects, responds to, reports, and recovers from security incidents.

Appendix J: Control Implementation Summary (CIS) & Customer Responsibility Matrix (CRM) Workbook

Use the FedRAMP-provided workbook on the FedRAMP Templates website to document how each control is implemented and indicate which responsibilities fall on the CSP versus the customer. This shared responsibility model is especially important for SaaS and PaaS providers.

Appendix K: FIPS 199 Worksheet

This worksheet captures the impact level (Low, Moderate, or High) determined by your FIPS 199 categorization. It helps define the appropriate FedRAMP baseline and is included as a table within the SSP.

Appendix L: CSO-Specific Laws and Regulations

List any specific legal, regulatory, or contractual requirements your CSO must meet, such as HIPAA or CJIS compliance. This content is also typically formatted as a table inside the SSP.

Appendix M: Integrated Inventory Workbook (IIW)

FedRAMP provides an Integrated Inventory Workbook (IIW) Template. Complete the FedRAMP-provided IIW template to document all hardware, software, and virtual assets within your authorization boundary. This helps assessors validate the scope and coverage of your controls.

Appendix N: Continuous Monitoring Plan

Create a plan that describes how you monitor system security over time, including scan frequency, alerting mechanisms, patch timelines, and reporting processes. While CSPs should use their own desired format for this plan, FedRAMP’s Continuous Monitoring Strategy Guide offers valuable direction for developing this appendix.

Appendix O: Plan of Action & Milestones (POA&M)

Submit a completed POA&M using the FedRAMP-provided POA&M template. This document lists known deficiencies, assigned owners, remediation timelines, and progress toward full compliance.

Appendix P: Supply Chain Risk Management Plan (SCRMP)

Develop your own SCRMP using guidance from NIST SP 800-161, which outlines how to assess, monitor, and mitigate risks from suppliers and third-party vendors.

Appendix Q: Cryptographic Module Table

Document your use of cryptographic modules using the FedRAMP provided Cryptographic Modules Table template. This includes information on FIPS 140-2 validation status and implementation details.

How to write a FedRAMP SSP

Writing a FedRAMP SSP requires more than simply filling out a template—it’s about clearly communicating how your system works, how it’s secured, and how you meet each FedRAMP control requirement. A poorly written or inconsistent SSP is one of the most common reasons for delays in authorization.

To create an SSP that satisfies reviewers and expedites the authorization process, cloud service providers should complete the following steps, which are based on guidance from the FedRAMP® CSP Authorization Playbook.

1. Review required training

Before writing your SSP, FedRAMP recommends completing the online training module FedRAMP System Security Plan (SSP) Required Documents (200-A), which provides a detailed overview of FedRAMP’s SSP template and its supporting documents. By completing this training before the actual writing process, you will have a foundational understanding of the documentation required for initial package submission. 

2. Use FedRAMP templates

It’s imperative that you use the official FedRAMP SSP baseline template and related appendices found on fedramp.gov and follow all instructions in these templates to ensure your documentation is complete and in the right format. 

While there’s only one SSP template for all baselines, some appendices have FedRAMP-provided templates that are specific to a particular baseline so it’s important you download and use the correct one. For example, FedRAMP provides an SSP Appendix A template for each baseline and CSPs must use the one that corresponds to the CSO’s required baseline.

2. Understand the criteria for document acceptance

The FedRAMP PMO evaluates every SSP against four key criteria:

• Clarity: Logical organization, defined terms, current dates, and correct grammar.
• Completeness: All required sections and appendices are included with sufficient detail.
• Conciseness: Language is direct, relevant, and appropriate to the audience.
• Consistency: Formatting, terminology, roles, and referenced documents are uniform throughout.

If your SSP has missing or vague content, conflicting terms, outdated references, or otherwise fails to meet these four criteria, it can slow down the review and extend your authorization timeline. 

Source: FedRAMP® CSP Authorization Playbook. 

3. Define your authorization boundary and data flows

The authorization boundary—what you are seeking authorization for and how federal data flows into, through, and out of that system—is the foundation from which the rest of your SSP is built.

To clearly and properly define this boundary, you must:

• Create a clear authorization boundary diagram (ABD) that shows all components within scope, including cloud infrastructure, applications, and external services.
• Develop data flow diagrams (DFDs) that map the movement of federal and sensitive system data across your environment.
• Identify any system interconnections, update services, or corporate-shared services that impact security posture.
• Review the FedRAMP Authorization Boundary Guidance provided by FedRAMP. 
• Follow all instructions in Section 8 of the FedRAMP SSP template, which details how to describe your system architecture, boundaries, and data flows.

4. Write strong control implementation statements

Appendix A of the SSP is where you describe how each FedRAMP control is implemented. This is the most time-consuming and important part of the SSP, and should be approached methodically.

For each control:

• Explain what is implemented, how it is implemented, and who is responsible for implementing, managing, and monitoring it.
• Address each and every requirement defined in the control (for example, AC-8 requires the system to (a) display a system use notification message before granting access to the system and (b) retain the message on screen until the user acknowledges the usage conditions by taking an explicit action)
• Pay attention to the verbs (for example, the control implementation statement for IR-5 must include a description of the process/tools employed to track security incidents as well as the process/tools employed to document security incidents)
• Select an implementation status (you may need to select more than one status for controls with multiple requirements)
• Use consistent terminology across the SSP, CIS/CRM, and supporting documents.
• Avoid restating the control requirement—instead focus on the who, what, where, when, why, and how.
• Point to specific policies, procedures, or configurations where possible but still provide a high-level description of how each control is implemented.

For shared or customer-provided controls, include a clearly labeled “Customer Responsibility” section within the control narrative to outline what customers must implement or configure.

5. Complete the control summary information tables

Each control in Appendix A also includes a summary information table. You must complete:

• Responsible role: The job title (not individual name) responsible for the control.
• Parameter values: Enter any required configuration details (e.g., MFA timeouts).
• Implementation status: Mark each control (and any control requirements within individual controls) as “Implemented,” “Planned,” or “Partially Implemented.”
• Control origination: Specify whether the control is inherited, hybrid, or fully implemented by your organization.Incorrect or inconsistent control origin designations are a frequent source of delays.

FedRAMP System Security Plan Checklist

Writing and maintaining an SSP is one of the most time-consuming and detail-heavy parts of the FedRAMP authorization process. This interactive checklist helps you stay organized and on track by breaking down the required components so you can ensure your SSP is complete, consistent, and ready for assessor review.

Use it to:

• Check off each section and appendix as you complete it
• Monitor your progress across writing, review, and revision stages
• Avoid common pitfalls that cause delays in authorization

Whether you're just getting started or preparing for reassessment, this checklist makes it easier to manage the documentation process.

Tips for success when writing your FedRAMP SSP

In addition to following the technical writing guidance above, we consulted with our in-house FedRAMP experts and former auditors to pull together best practices that can help you write a stronger, more defensible SSP. Whether you're navigating the FedRAMP process for the first time or refining your documentation ahead of reassessment, these tips will set you up for success.

Use FedRAMP templates and follow instructions carefully

The official FedRAMP SSP and appendix templates include instructional text describing the expected level of detail for each section. Reviewers expect every section to be filled out as instructed. 

In addition to following all instructions, make sure you’re using 

• The most up-to-date version of the FedRAMP template
• The template for your specific baseline, if available

Involve stakeholders across your organization

Writing a comprehensive and accurate SSP requires input from multiple teams. Involve subject matter experts across:

• IT and cloud infrastructure
• Security and compliance
• Legal and policy
• DevOps and engineering
• Leadership and executive sponsors

This collaboration ensures that your SSP accurately reflects both technical operations and governance structures.

Focus on current, implemented controls only

Document only what is currently implemented and operational. If a control is still being developed or partially implemented, it must be marked accordingly in the summary table and tracked in your POA&M.

Describing any planned or aspirational security controls in your SSP might seem like a good idea, but this will trigger findings during your assessment.

Back up every claim with evidence

Refer to internal policies, procedures, and configuration standards to support your control responses wherever possible. The more evidence you provide, the easier it is for assessors to validate your implementation.

Whenever you reference another document or appendix, be specific. Use filenames, section numbers, and page references to help reviewers locate the evidence quickly.

Treat your SSP as the foundation for assessment

The SSP isn’t just a document. It’s a roadmap for assessors and agencies to follow. A well-structured, detailed SSP helps build trust with reviewers and lays the groundwork for a smoother security assessment.

Work with an expert technical writer

You need a strong technical writer with security experience to develop your SSP. If you don’t have one, bring in help. Many FedRAMP-recognized 3PAOs and other organizations listed in the FedRAMP Marketplace offer advisory services to support SSP development.

Hiring a virtual CISO (vCISO) or FedRAMP consultant can also significantly accelerate the process. 

These experts can:

• Lead documentation efforts
• Ensure alignment with FedRAMP expectations
• Help you avoid common pitfalls
• Cut down the time required to write a thorough SSP

Leverage automation to streamline documentation

Given the depth and detail required for a FedRAMP SSP, a manual approach can quickly become overwhelming and take between 4-6 months to complete.

Automation can help reduce errors, ensure consistency, and accelerate the process.

Look for a tool that can:

• Auto-populate fields based on integrations with your tech stack
• Offer step-by-step guidance for completing each required section accurately and completely
• Track version history and make it easy to update
• Allow you to link POA&M items directly to framework requirements in your SSP
• Automatically calculate your SPRS score based on SSP implementation statuses

This type of automation tool can save you hundreds of hours and help you maintain a single source of truth as your environment evolves.

FedRAMP 20x & The Future of SSPs

The FedRAMP program is in the midst of a major modernization effort called FedRAMP 20x. This update is designed to streamline the authorization process and reduce the time and complexity it takes for cloud service providers to get authorized. Since the SSP alone can take months to write, it is ripe for disruption.

While an SSP is not required for the FedRAMP 20x Phase One pilot pathway to Low authorization, requirements for the SSP and related documents are likely to change in future pilot programs for Moderate and High authorization.

Since FedRAMP 20x introduces a shift toward structured data, standardized evidence exchange, and more efficient security assessment workflows, in the future, portions of the SSP may be expressed in modular or machine-readable formats rather than a single static document. Moving toward machine-readable, real-time SSP updates reflects the increasingly important role of continuous monitoring inFedRAMP 20x.

To stay aligned with the 20x approach:

• Keep your policies up-to-date at all times
• Use baseline templates and structured content
• Organize supporting FedRAMP documentation and artifacts in an accessible, version-controlled repository
• Prepare your teams for more automation in the review and security authorization process
• Build and maintain a trust center for compliance, vendor diligence, and continuous monitoring deliverables
• Use a compliance automation platform to shift from point-in-time assessments to real-time security monitoring and continuous compliance

Developing an effective SSP for your FedRAMP Authorization

The FedRAMP SSP plays a central role in your authorization journey. It helps demonstrate that your cloud service offering meets the strict information security standards required to serve federal agencies, and that your team understands its security responsibilities.

As the FedRAMP program evolves, organizations that keep their SSPs structured, updated, and actionable will be better prepared for the future of federal cloud computing. Writing a clear, complete, and well-supported SSP not only strengthens your security posture but also builds trust with reviewers, partners, and government customers.

To simplify this process, Secureframe offers a purpose-built SSP builder that helps you generate a comprehensive, audit-ready SSP. As part of the Secureframe Federal package, our tool includes:

• Pre-built templates tailored to FedRAMP, CMMC, and other federal frameworks
• Step-by-step guidance for completing each required section
• Version control and update tracking to reflect evolving architecture or control implementations

By building and managing your SSP within the Secureframe platform, you can ensure your documentation remains accurate, consistent, and ready for assessor review. This can save you hundreds of hours and reduce the risk of delays. 

Additionally, because Secureframe Federal unifies documentation, remediation tracking, and continuous evidence collection in one platform unlike stand-alone SSP tools, you can meet all CMMC requirements faster and stay compliant over time.