Configuration Management PlanTemplate, Baseline Configurations, Security Impact Analysis, and Change Control for NIST 800-171 and CMMC
A configuration management plan is the document that states how an organization defines, records, protects, and changes the configuration of its systems: what the approved baseline for each system looks like, which security settings are enforced, how changes are reviewed and approved, how their security impact is analyzed before they happen, and who is allowed to make them. Petronella Technology Group has written and operated configuration management for regulated businesses in Raleigh and across North Carolina since 2002, and this page explains what the plan must contain to satisfy NIST SP 800-171 and CMMC, how to build the baselines it depends on, and a template you can adopt this week.
- The plan describes a system, not a wish. A configuration management plan is only as real as the baselines, settings, inventory, and change records behind it. Assessors read the plan first and then ask for the artifacts it promises.
- NIST SP 800-171 has nine configuration management requirements, and the plan is where they live together. Controls 3.4.1 through 3.4.9 cover baselines, security settings, change control, security impact analysis, access restrictions for change, least functionality, and control of user-installed software. One plan can address all nine.
- The baseline is the foundation. If you cannot state what a correctly configured server, workstation, firewall, or cloud tenant looks like, you cannot detect drift, analyze the impact of a change, or prove least functionality.
- Security impact analysis is a paragraph, not a project. Control 3.4.4 is satisfied by a short, recorded answer to a fixed set of questions before each change, and it is the requirement CMMC assessors most often find missing from otherwise good change tickets.
- The same plan serves CMMC, SOC 2, PCI DSS, and ISO 27001. Every one of those frameworks asks for secure configuration standards and controlled change. Written framework-neutral, the plan is evidence for all of them.
What Is a Configuration Management Plan?
A configuration management plan (often shortened to CM plan or CMP) is the governing document for how an organization controls the configuration of its information systems across their life cycle. In the security sense used by NIST, CMMC, and every major compliance framework, it answers a specific set of questions: which systems and components are under configuration control, what the approved baseline configuration of each is, which security configuration settings are enforced and where they come from, how proposed changes are requested, reviewed, approved, and logged, how the security impact of each change is analyzed before implementation, who is permitted to make changes and how that permission is enforced, how systems are limited to essential functions, and how unauthorized or user-installed software is prevented or monitored.
The phrase also has a second meaning in project management, where a configuration management plan describes how a project's deliverables and documents are versioned and controlled. That usage comes from the PMBOK Guide and from engineering configuration management standards such as ANSI/EIA-649, and it is the one most project management study guides describe. The two are related, since both trace changes to a controlled item, but a compliance assessor asking for your configuration management plan means the security document, and that is what this page covers.
NIST SP 800-53 Revision 5 defines the document directly in control CM-9, Configuration Management Plan, which requires a plan that addresses roles, responsibilities, and configuration management processes and procedures, establishes a process for identifying configuration items throughout the system development life cycle, defines the configuration items for the system, and is reviewed, approved, and protected from unauthorized disclosure and modification. NIST SP 800-171 Revision 2, the standard behind CMMC Level 2, does not list a separate requirement to write the plan. Its Appendix E tailors CM-9 out as a control nonfederal organizations are expected to satisfy without specification. The practical effect is that the assessor still expects the plan to exist, because it is the only sensible place to document how controls 3.4.1 through 3.4.9 are implemented.
Petronella Technology Group has provided cybersecurity, compliance, and managed IT services from Raleigh, North Carolina since 2002 and is a CyberAB Registered Provider Organization (RPO #1449). Configuration management is one of the fourteen control families we implement for defense contractors preparing for CMMC, and the plan on this page is the structure our engineers use, adapted so that a business can adopt it with its own tools and staff. Our CMMC configuration management page lists the practices in the family; this page explains the plan that ties them together.
- A statement of scope: which systems, components, and environments are configuration items under control
- The approved baseline configuration for each class of system, with the source of its hardening settings
- The change control process, including the security impact analysis performed before implementation
- The access restrictions that determine who can change what, and how those restrictions are enforced technically
- The least-functionality and software-control rules that keep systems at the baseline between changes
- The review cadence, the roles that own each activity, and the records retained as evidence
- Not a copy of the NIST control text with "we do this" written after each line
- Not the change management policy alone; change control is one section of the plan, not the whole of it
- Not a project deliverable version-control plan, though the same name is used in project management
- Not a tool export; a screenshot of a configuration management database is evidence for the plan, not a substitute for it
- Not something that stays valid once written; a baseline that has not been reviewed in a year is an assumption, not a baseline
What the Plan Must Cover: NIST SP 800-171 Controls 3.4.1 Through 3.4.9
The configuration management family in NIST SP 800-171 Revision 2 has nine requirements, assessed under CMMC 2.0 Level 2 as practices CM.L2-3.4.1 through CM.L2-3.4.9. The table maps each requirement to the section of the plan that addresses it and the evidence an assessor will ask to see. Revision 3 renumbers the family as 03.04 and adds explicit component inventory, information location, and high-risk configuration requirements, which the same plan sections absorb.
Each of the nine has its own assessment objectives in NIST SP 800-171A, and the objectives are what the CMMC assessor actually scores. Control 3.4.1, for instance, has six: a baseline is established; it includes hardware, software, firmware, and documentation; it is maintained; an inventory is established; it includes the same four categories; and it is maintained. The plan should be written so that a reader can find each objective's answer without searching. Our pages on NIST 3.4.1, NIST 3.4.2, NIST 3.4.3, and NIST 3.4.4 walk through the objectives for the four most-sampled controls.
How to Build a Configuration Management Plan in Eight Steps
The steps below are the order Petronella Technology Group follows when standing up configuration management for a client. The sequence matters: every later step depends on the inventory and baselines produced by the first three, and organizations that start by writing the change control section usually discover they cannot define what a "change" is because they never defined the starting state.
Define scope and configuration items: list every system class in the assessment boundary (servers, workstations, network devices, cloud tenants, security tools, mobile devices) and decide which are configuration items under control
Build or verify the inventory: every configuration item gets an identifier, an owner, a location, its hardware, software, and firmware versions, and its role, so the baseline has something to attach to
Establish baselines: for each system class, document the approved operating system build, installed software, enabled roles and services, network configuration, patch level, and the hardening benchmark applied
Adopt and enforce security configuration settings: choose the benchmark (CIS Benchmarks, DISA STIGs, or vendor security baselines) per platform, record approved deviations with justification, and enforce through policy, images, or configuration management tooling
Write the change control process: request, classification, review, approval, logging, and the post-change baseline update, with the roles that perform each
Add the security impact analysis: a fixed set of questions answered and recorded before every non-standard change, with the reviewer named
Define access restrictions and software control: who may change each system class, the privileged accounts and physical controls that enforce it, and the application allowlisting or installation restrictions that keep systems at baseline
Set the monitoring and review cadence: how drift from baseline is detected, how often baselines and the plan are reviewed, and where the records are kept as evidence
Step 3 is where most of the work is. A baseline is not a sentence that says "Windows Server 2022, hardened." It is a specific record: the build and patch level, the roles and features installed and the ones explicitly removed, the services set to disabled, the local security policy or group policy objects applied, the installed agents (endpoint protection, monitoring, backup, logging), the network interfaces and firewall rules, the local accounts that exist and the ones that were removed, and the benchmark version the settings came from. Organizations that build from golden images or infrastructure-as-code already have this; the plan just has to point at the image or the code repository and describe how it is versioned. Organizations that built systems by hand have to capture it, and a configuration export from each system class plus a benchmark scan is the fastest way. The hardening work that produces the baseline, and the benchmark choice behind it, is described on our system hardening services page.
Step 5 should reuse the change management process you already have. If the organization runs a change advisory board and a change record, the configuration management plan references it rather than inventing a second process. The plan adds two things the general IT change process often lacks: the requirement that every approved change updates the affected baseline, and the security impact analysis in step 6. Our IT change management process and template page describes the change record and approval paths in detail; the plan on this page assumes that process exists and layers the configuration-specific requirements onto it.
Step 8 is the one that keeps the plan true. Drift is inevitable. An administrator enables a service to troubleshoot, a vendor update re-enables a protocol, a user with local admin installs a tool. Without a detection mechanism (a benchmark scan on a schedule, a configuration management tool that reports non-compliance, or at minimum a quarterly manual comparison), the baseline document and the real system diverge, and the assessor's sample finds the difference. The least functionality requirement in particular is assessed by looking at what is actually running, not what the baseline says should be.
Not Sure Whether Your Baselines Would Survive an Assessment Sample?
Send us your current baseline document for one system class and the last three change records that touched it. In a short scoping call we can tell you which NIST SP 800-171 objectives they satisfy, which an assessor would mark as not met, and the smallest set of changes that closes the gap for a business your size.
Baseline Configuration: What to Record for Each System Class
A baseline configuration is the documented, approved state of a system class at a point in time. It is the reference every later activity compares against: change control decides whether a proposal deviates from it, security impact analysis asks what the deviation exposes, least functionality is measured against it, and drift detection reports departures from it. The cards below list what a complete baseline record contains. Most organizations need between five and ten baselines, one per class, rather than one per machine.
Platform and build
Operating system or firmware, edition, version, and build number; the patch level or cumulative update as of the baseline date; the golden image identifier or infrastructure-as-code commit that produces it; and the hardware model or cloud instance type it applies to.
Hardening settings and their source
The benchmark applied (CIS Benchmark level and version, DISA STIG version, or vendor baseline), the enforcement mechanism (group policy, configuration profile, image, or configuration management tool), and every approved deviation from the benchmark with the reason and the approver.
Installed software and agents
The approved software list for the class, including endpoint protection, monitoring, backup, logging, and remote management agents, with versions; and the software explicitly prohibited. This list feeds the allowlisting policy required by control 3.4.8.
Roles, services, ports, and protocols
The roles and features enabled, the services running and their startup type, and the listening ports and protocols permitted, each with a business justification. Everything not listed is disabled. This is the least functionality standard for the class and the evidence for controls 3.4.6 and 3.4.7.
Accounts and access
The local accounts that exist (and the default accounts renamed or disabled), the groups with administrative rights, the privileged access method (separate admin accounts, privileged access workstations, or a vault), and the authentication settings such as multi-factor requirements and lockout thresholds.
Network and logging configuration
Interfaces, addressing, VLAN or security group membership, host firewall rules, DNS and time sources, and the logging configuration: what is logged, where it forwards, and the retention period. For CMMC environments, whether the class is inside or outside the CUI boundary and how that is enforced.
Choosing a benchmark: CIS, DISA STIG, or vendor baseline
Control 3.4.2 does not name a benchmark; it requires that security configuration settings be established and enforced. The plan has to say which settings and where they came from. CIS Benchmarks are the most common choice for commercial businesses because they cover nearly every operating system, browser, database, and cloud platform, and Level 1 profiles are designed to be applied without breaking normal operation. DISA Security Technical Implementation Guides are stricter, written for Department of Defense systems, and are what many defense contractors adopt because their prime contractors and assessors are familiar with them. Vendor security baselines, such as the Microsoft security baselines for Windows and Microsoft 365, are a reasonable floor when neither of the others has been adopted yet. Whichever is chosen, the assessor will look for three things: the benchmark is named with a version, deviations are documented with a reason, and a scan or report shows the settings are actually in place. The NIST SP 800-53B control baselines are a different concept, a selection of controls rather than system settings, and the two should not be confused in the plan.
Security Impact Analysis: The Template and Worked Examples
Control 3.4.4 requires that the security impact of a change be analyzed before the change is implemented. In practice it is a short, structured record attached to the change request, completed by someone with security responsibility rather than the person implementing the change, and dated before the approval. The template Petronella Technology Group uses asks seven questions. If every answer is "no change," the analysis is complete in two minutes. If any answer is "yes," the change is at least medium risk and the answer has to say what compensates.
- Baseline deviation: does the change alter a documented baseline for any system class? If so, which baseline elements, and will the baseline document be updated as part of the change?
- Attack surface: does the change open a port, enable a protocol or service, install software, add a listening interface, or expose a system to a new network or the internet?
- Privilege and access: does the change create, elevate, or broaden any account, group, role, API key, or service principal, or alter who can reach the system physically or logically?
- Data location and flow: does the change move, copy, or expose regulated data (CUI, PHI, cardholder data) to a new system, a new provider, or a location outside the assessed boundary?
- Security controls affected: does the change touch logging, monitoring, backup, encryption, multi-factor authentication, endpoint protection, or the firewall, and could it silently reduce their coverage?
- Compliance and documentation: does the change affect a control implementation described in the system security plan, a policy, a network diagram, or the inventory, and which documents need updating?
- Result and reviewer: the resulting risk level, any compensating measures required before or after implementation, the reviewer's name and role, and the date, which must precede the approval date
- Monthly workstation patching through the RMM platform: no baseline deviation (the baseline states the patch cadence), no new attack surface, no privilege change, no data movement, no control affected. Low risk; standard change; analysis recorded once for the category and referenced by each run.
- Opening TCP port 3389 on a server's host firewall for a vendor: baseline deviation (ports list), attack surface increased, access broadened to an external party. Medium to high risk; compensating measures required: source restriction to the vendor's addresses, multi-factor authentication on the account, session logging, and an expiry date on the rule. The baseline is updated or an approved deviation is recorded.
- Migrating a file share containing CUI to a new cloud storage provider: data location changes, boundary changes, the system security plan and network diagram need updating, encryption and logging must be confirmed on the new provider. High risk; requires the provider's FedRAMP or equivalent status confirmed and the system security plan revised before cutover.
- Disabling an endpoint protection agent to troubleshoot a performance issue: a security control is reduced. Even as a temporary emergency change, the analysis records the systems affected, the duration, the compensating monitoring, and the re-enablement check. This is the example assessors use to test whether emergency changes get an analysis at all.
The most common finding against 3.4.4 is not that the analysis was done badly but that it was not done at all, or that the change ticket contains a "risk" field with a single word in it and no reasoning. The template above is deliberately short so that it gets completed. The second most common finding is timing: an analysis written after implementation, or on the same day with no evidence of order, does not satisfy "prior to implementation." A ticketing system that timestamps the analysis field separately from the approval field solves this without any extra effort from the engineer.
What Changes When the Plan Describes a Real System
"Our baseline is whatever the last admin set up"
Servers were built by hand over several years by different people. No two are configured alike, nobody can say which services should be running, and the assessor's request for the baseline document produces a shrug.
Settings exist but cannot be proven
Group policy applies some hardening, but nobody knows which benchmark it was based on, several policies have been edited to fix application problems, and no scan has ever compared the result to a standard.
Change tickets have a blank risk field
Changes get a ticket and an approval, but the security impact is never written down. The assessor samples five changes and marks 3.4.4 as not met for all of them.
Local admins install what they like
Half the workstations have software no one approved. There is no allowlist, no monitoring of installations, and the inventory in the system security plan is a year out of date.
Seven baselines, each two pages, each dated
Every system class has a documented baseline with a benchmark source, an approved-deviations list, and a review date. New systems are built from the image or the code that produces the baseline, and the document points at it.
Enforcement is scanned, not assumed
A benchmark scan runs on a schedule and reports every system's compliance against its baseline. Deviations are either remediated or approved and recorded. The scan report is the 3.4.2 evidence.
Every change carries a seven-question analysis
The security impact analysis is a required field with a separate timestamp. Standard changes reference a category analysis; everything else gets its own. The assessor's sample finds the analysis, dated before approval, in every record.
Software is allowlisted and installations are reported
Application control permits the approved list and blocks the rest. Users request exceptions through the change process. The monthly installation report goes into ComplianceArmor® as the 3.4.9 evidence alongside the plan.
Configuration Management Plan Template: The Document Outline
The outline below is the structure of the plan itself. It is written to satisfy NIST SP 800-53 CM-9, the nine NIST SP 800-171 requirements, and the CMMC assessment objectives without framework-specific language, so one document serves every assessment. A complete plan for a small or mid-sized business runs eight to fifteen pages plus the baseline records as appendices. Each section names an owner; a plan without owners is a description, not a control.
- 1. Purpose, scope, and authority: what the plan governs, which environments and boundaries it covers (production, CUI enclave, test, development), the frameworks it satisfies, and the executive who approved it
- 2. Roles and responsibilities: the configuration manager, system owners, change approvers, the security reviewer who performs impact analysis, and the assessor-facing evidence owner, with named people or positions
- 3. Configuration items and inventory: the system classes under control, the identifier scheme, where the inventory lives, how it is kept current, and how it links to the system security plan
- 4. Baseline configurations: the baseline record format, the list of baselines by class (as appendices), how new systems are built to baseline, and the review cadence
- 5. Security configuration settings: the benchmark or STIG adopted per platform with version, the enforcement mechanism, the approved-deviation process, and the compliance scanning schedule
- 6. Configuration change control: the change types, the request and approval workflow, logging, the requirement that approved changes update the baseline, and the emergency change path
- 7. Security impact analysis: the seven-question template, who completes it, the timing rule, and how the result feeds approval and risk level
- 8. Access restrictions for change: who may change each class, the privileged account model, physical access to equipment, and the technical enforcement of both
- 9. Least functionality and software control: the essential-capabilities standard, the ports, protocols, and services list, the software allowlisting policy, and the user-installed software restriction and monitoring
- 10. Monitoring, drift detection, and review: how deviations from baseline are detected and remediated, the plan and baseline review cadence, and metrics reported to management
- 11. Records and evidence: what is retained, where, for how long, and how it is exported for an assessment
- 12. Plan protection and revision history: access controls on the plan itself, version, approval signature, and change log
- Identification: system class name, baseline version, effective date, owner, and the systems in the inventory it applies to
- Platform: operating system or firmware, edition, version, build, patch level as of the effective date, and the image or code reference that produces it
- Hardening source: benchmark name, level, and version; enforcement mechanism; and the approved-deviations table with justification and approver for each
- Software: approved applications and agents with versions; prohibited software; and the allowlisting configuration reference
- Roles, services, ports, protocols: the enabled list with justifications; the explicit statement that all others are disabled
- Accounts and privileges: local accounts, administrative groups, default account handling, and authentication settings
- Network and logging: interface and segmentation membership, host firewall summary, time and DNS sources, log sources and forwarding destination, and retention
- Boundary and data: whether the class stores, processes, or transmits CUI, PHI, or cardholder data, and the controls that keep it inside the boundary
- Verification: the scan or check that confirms compliance with this baseline, its schedule, and the date and result of the last run
- Review: last review date, next review date, and the changes since the previous version
The plan depends on three other documents already existing: the system inventory, the system security plan, and the change management policy. Section 3 points at the inventory rather than duplicating it; section 6 points at the change process; and the whole plan is referenced from the configuration management section of the system security plan. Our IT asset inventory page covers the inventory, the system security plan page covers how the plan is referenced there, and any requirement the plan cannot yet meet goes on the plan of action and milestones with an owner and a date rather than being described as if it were done.
Configuration Management Requirements in CMMC, NIST 800-53, SOC 2, PCI DSS, ISO 27001, and CIS Controls
Secure configuration and controlled change appear in every major framework. That makes the configuration management plan unusually efficient: written once and framework-neutral, it is evidence for all of them, and the baseline records and change logs behind it are the artifacts each assessor samples.
CMMC 2.0 Level 2 and NIST SP 800-171
Practices CM.L2-3.4.1 through CM.L2-3.4.9 are assessed against the NIST SP 800-171A objectives described above. Craig Petronella, CMMC Registered Practitioner and author of the CMMC 2.0 Certification Guide, has seen this family produce more "not met" objectives than its size suggests, almost always because baselines were never written down or impact analysis was never recorded. Our CMMC compliance services and CMMC readiness assessment build the plan and its evidence before the C3PAO arrives.
NIST SP 800-53 Revision 5
The CM family in SP 800-53 is the source: CM-2 Baseline Configuration, CM-3 Configuration Change Control, CM-4 Impact Analyses, CM-5 Access Restrictions for Change, CM-6 Configuration Settings, CM-7 Least Functionality, CM-8 System Component Inventory, CM-9 Configuration Management Plan, and CM-11 User-Installed Software. Organizations subject to FedRAMP, FISMA, or a NIST SP 800-53 moderate baseline write the same plan with CM-9's explicit requirements as the checklist.
SOC 2 (Trust Services Criteria)
Common criterion CC7.1 expects the entity to use detection and monitoring procedures to identify changes to configurations that result in the introduction of new vulnerabilities, and CC8.1 covers authorized, tested, approved, and documented changes to infrastructure and software. The baseline scanning and change control sections of the plan are the direct evidence. See our SOC 2 compliance services.
PCI DSS v4.0
Requirement 2.2 requires that system components are configured and managed securely, with configuration standards developed, implemented, and maintained, covering vendor defaults, necessary services and protocols, and insecure services. Requirement 6.5.1 covers change control with documented security impact. The plan's baseline and settings sections are the configuration standards the assessor asks for. Our PCI DSS compliance page covers the rest of the standard.
ISO/IEC 27001:2022 and CIS Controls
Annex A control 8.9, Configuration management, requires that configurations including security configurations of hardware, software, services, and networks be established, documented, implemented, monitored, and reviewed, and control 8.32 covers change management. CIS Controls version 8 puts the same requirements in Control 4, Secure Configuration of Enterprise Assets and Software. The ISO 27001 auditor and a CIS-based assessment both accept the same plan.
Evidence in ComplianceArmor®
The ComplianceArmor® platform holds the configuration management plan as a controlled document, the baseline records as appendices, and the scan reports, change logs, and installation reports as evidence mapped to each framework's control. When an assessor asks for CM.L2-3.4.2 or PCI DSS 2.2 evidence, the answer is a filtered export rather than a search. Details are on the ComplianceArmor® platform page.
Six Ways Configuration Management Plans Fail an Assessment
The plan restates the control text
A document that copies each NIST requirement and follows it with "the organization does this" describes nothing. The assessor cannot find the baseline, the benchmark, or the change process in it, and marks the objectives as not met. The fix is to write the plan about your systems, with the names of your tools, your system classes, and your people.
Baselines exist for servers only
Workstations, network devices, cloud tenants, and mobile devices are configuration items too, and the ones most often missing a baseline. An assessor who finds a server baseline will ask for the firewall's and the Microsoft 365 tenant's next. The fix is one baseline per system class in the boundary, however short.
Settings are not scanned
The plan names a benchmark but nothing verifies it is applied. The assessor examines a system, finds a setting that does not match, and 3.4.2 is not met. The fix is a scheduled compliance scan against the named benchmark with the report retained, and a deviations table for every mismatch that is intentional.
Changes do not update the baseline
The change process works, but the baseline document never changes, so within a year it describes a system that no longer exists. The fix is a mandatory "baseline updated" step in the change record for any change that alters a baseline element, and a periodic reconciliation between scan results and the document.
Impact analysis is a checkbox
A risk field with "low" in it and no reasoning is not an analysis, and one written after the change is not "prior to implementation." The fix is the seven-question template with a separate timestamp and a named reviewer who is not the implementer.
Local administrators undo it all
Every user with local admin rights can install software, change settings, and disable agents, so the baseline is a suggestion. The fix is removing standing local admin, allowlisting software, and routing exceptions through the change process; without it, controls 3.4.5, 3.4.8, and 3.4.9 are all at risk together.
How Petronella Technology Group Builds and Operates Configuration Management
Petronella Technology Group was founded in Raleigh in April 2002, has held a BBB A+ rating since 2003, and is a CyberAB Registered Provider Organization. Configuration management is one of the fourteen control families we implement for defense contractors and one of the disciplines built into every environment we manage for healthcare, financial, legal, and manufacturing clients. Here is what the engagement looks like.
- A configuration management plan written for your environment, your frameworks, and your tools, following the outline on this page, stored in ComplianceArmor® as a controlled document with version history
- A verified system inventory and a baseline record for every system class in the assessment boundary, built from configuration exports and benchmark scans rather than from memory
- A benchmark adopted per platform (CIS, DISA STIG, or vendor baseline) with an approved-deviations table, enforced through group policy, configuration profiles, images, or configuration management tooling
- The security impact analysis template integrated into your change workflow as a required, separately timestamped field, with our security reviewer completing it for managed environments
- Application allowlisting and removal of standing local administrator rights, with an exception process that runs through change control
- Scheduled compliance scanning against each baseline with reports retained as evidence, and drift remediated as a standard change
- Patch management operated as a standard change with retained post-run reports through our patch management service, so the baseline's patch level stays true
- Quarterly evidence exports mapped to CMMC, NIST SP 800-53, SOC 2, PCI DSS, or ISO 27001 controls, and support during the assessment when the sample is pulled
- Craig Petronella, founder and CEO, is a CMMC Registered Practitioner, an NC Licensed Digital Forensics Examiner (License 604180-DFE), and MIT-certified in cybersecurity. His forensics work is where baselines prove their value: an investigation into a compromised system that has a documented baseline can identify what the attacker changed in hours, and one without it may never be certain.
- His book CMMC 2.0 Certification Guide covers all 110 NIST SP 800-171 controls, including the configuration management family, SPRS scoring, and C3PAO assessment preparation, and the plan structure on this page is the one it recommends.
- "Petronella Cybersecurity provides outstanding service! Their team is extremely knowledgeable, responsive, and truly cares about protecting their clients. They take the time to explain complex issues in simple terms and deliver real solutions, not just promises." (GB Entraînement, verified TrustIndex review)
- Rated 4.7 across 92 verified TrustIndex reviews and 5.0 across 15 Google reviews
- Founded 2002, BBB A+ since 2003, CyberAB Registered Provider Organization #1449, entire team CMMC-RP certified
- The plan is written to be operated, not filed: every section has an owner and a cadence, and the evidence behind it is produced by the same tools that run your environment
For defense contractors, the plan is usually built as part of a broader NIST SP 800-171 effort; the NIST 800-171 compliance page describes the full program, the CMMC gap assessment is where we find out which of the nine requirements are already met, and the C3PAO assessment page explains what the certified assessor will sample from the plan. For contractors moving to Revision 3, the NIST 800-171 Rev 3 page covers the renumbered 03.04 family and its new inventory, information location, and high-risk configuration requirements.
No Plan vs. Policy-Only vs. an Operated Configuration Management Plan
Most organizations preparing for a first assessment are in the middle column: a policy exists, some hardening is applied, but the baselines and evidence that would let an assessor verify it do not. The right column is what the frameworks require and what the plan on this page produces.
Configuration Management Plan: Frequently Asked Questions
What is a configuration management plan in simple terms?
It is the document that says what your systems are supposed to look like and how you keep them that way. It lists the systems under control, the approved baseline configuration for each type, the security settings enforced and where they came from, the process for reviewing and approving changes, the security impact analysis done before each change, who is allowed to make changes, and how you detect and fix drift. Assessors for CMMC, SOC 2, PCI DSS, and ISO 27001 all ask for it under slightly different names.
Does NIST SP 800-171 require a configuration management plan?
Not by that name. NIST SP 800-171 Revision 2 tailors out the SP 800-53 control CM-9, Configuration Management Plan, as a requirement nonfederal organizations are expected to satisfy without being told to. What it does require is the substance: baseline configurations and inventories (3.4.1), enforced security settings (3.4.2), change control (3.4.3), security impact analysis (3.4.4), access restrictions for change (3.4.5), least functionality (3.4.6 and 3.4.7), authorized software policy (3.4.8), and control of user-installed software (3.4.9). A plan is the practical way to document all nine, and CMMC assessors expect to read one.
What is a baseline configuration?
A baseline configuration is the documented, approved state of a class of systems at a point in time: the operating system build and patch level, the hardening benchmark applied and any approved deviations, the installed software and agents, the enabled roles, services, ports, and protocols, the accounts and privileges, and the network and logging configuration. It is the reference that change control, impact analysis, least functionality, and drift detection all compare against. Most organizations maintain one baseline per system class rather than one per machine.
What should a security impact analysis include?
A short, recorded answer to a fixed set of questions before the change is implemented: whether the change deviates from a baseline, whether it increases attack surface (ports, services, software, exposure), whether it creates or broadens privileges or access, whether it moves regulated data or crosses the assessed boundary, whether it affects a security control such as logging, backup, encryption, or endpoint protection, and which documents need updating. It ends with the resulting risk level, any compensating measures, the reviewer's name, and a date that precedes the approval. That satisfies NIST SP 800-171 control 3.4.4.
Which hardening benchmark should the plan use: CIS or DISA STIG?
NIST SP 800-171 control 3.4.2 does not name one; it requires that settings be established and enforced and that the plan say which. CIS Benchmarks suit most commercial businesses because they cover nearly every platform and the Level 1 profiles rarely break operations. DISA STIGs are stricter and are common among defense contractors whose primes and assessors expect them. Microsoft or other vendor security baselines are a reasonable starting floor. Whichever you choose, name the version, document every deviation with a reason, and scan to prove it is applied.
How is a configuration management plan different from a change management policy?
Change management governs how changes are requested, approved, scheduled, and reviewed. The configuration management plan is broader: it defines the baseline state that changes deviate from, the security settings enforced, the impact analysis performed, the access restrictions on who can change what, the least-functionality and software-control rules, and drift detection. Change control is one section of the configuration management plan, and the plan should reference the existing change process rather than duplicate it.
How often should baselines and the plan be reviewed?
Baselines should be updated whenever an approved change alters a baseline element, and reviewed on a schedule regardless, with annual review the common minimum and more frequent review for classes that change often, such as cloud tenants. The plan itself is reviewed annually and whenever the environment, the frameworks in scope, or the tooling changes. Compliance scanning against baselines should run far more often, typically weekly or monthly, so that drift is caught between reviews rather than by the assessor.
Does Petronella Technology Group write configuration management plans?
Yes. We write the plan for your environment and frameworks following the outline on this page, build the inventory and baseline records from configuration exports and benchmark scans, adopt and enforce a hardening benchmark per platform, integrate the security impact analysis into your change workflow, implement application allowlisting and privileged access controls, run scheduled compliance scanning, and export the evidence through ComplianceArmor® for CMMC, NIST SP 800-53, SOC 2, PCI DSS, or ISO 27001 assessments. Call 919-348-4912 or schedule a free consultation to discuss your environment.
Related Compliance and Managed IT Pages
CMMC Configuration Management Family
→IT Change Management Process
→IT Asset Inventory
→System Security Plan
→Plan of Action and Milestones
→CMMC Enclave
→SPRS Score Calculator
→ComplianceArmor® Platform
→Last Updated: September 10, 2026 (first published September 9, 2026). This page references NIST SP 800-171 Revision 2 controls 3.4.1 through 3.4.9 and Revision 3 family 03.04, NIST SP 800-171A assessment objectives, CMMC 2.0 Level 2 practices CM.L2-3.4.1 through CM.L2-3.4.9, NIST SP 800-53 Revision 5 controls CM-2 through CM-9 and CM-11, SOC 2 Trust Services Criteria CC7.1 and CC8.1, PCI DSS v4.0 requirements 2.2 and 6.5.1, ISO/IEC 27001:2022 Annex A controls 8.9 and 8.32, and CIS Controls v8 Control 4. Confirm current requirement text with the issuing body before relying on it for an assessment.
Know What Your Systems Should Look Like, and Prove It
Petronella Technology Group has implemented configuration management for regulated businesses since 2002, holds a BBB A+ rating dating to 2003, and is a CyberAB Registered Provider Organization. Tell us about your environment and your frameworks, and we will show you the smallest configuration management plan that satisfies the assessor and keeps your systems at baseline.