# NIST SP 800-53 Rev. 5 CA-9 — Internal System Connections - Source: https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ca-9-internal-system-connections - Section: [Compliance](https://support.icompaas.com/compliance) › [NIST SP 800-53 Rev. 5 Controls](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5) › CA — Assessment, Authorization, and Monitoring - Last updated: 2026-06-05 - Publisher: iCompaas, Inc. (https://www.icompaas.com) **NIST SP 800-53 Rev. 5**·Control `CA-9`·high·Component: **Assessment, Authorization, and Monitoring** ## What this control requires > Authorizes, documents, and reviews internal system connections, specifying interface characteristics, security requirements, and conditions for termination. This control supports the Internal Connection Manager capability within the Assessment, Authorization, and Monitoring family. > > — NIST SP 800-53 Rev. 5, Control CA-9 ### In plain English Authorizes, documents, and reviews internal system connections, specifying interface characteristics, security requirements, and conditions for termination. In practice, this means you can prove you policy management-level controls on a defined cadence. ## Why it matters SP 800-53 is the catalogue every U.S. federal authorisation (FedRAMP, FISMA, CMMC) and most regulated industries point at. A missing control surfaces as a Plan of Action & Milestones (POA&M) item that an Authorizing Official must approve before the Authority To Operate is granted or renewed. This control is rated **high**. Auditors expect a named owner, a remediation SLA, and a tooling artefact that evidences continuous operation. ## What an auditor looks for A 3PAO (FedRAMP) or Independent Assessor (NIST RMF) tests against NIST SP 800-53A assessment procedures. For each control they expect a documented implementation that addresses every assessment objective (Examine, Interview, Test) and an implementation summary in the System Security Plan. Within **Assessment, Authorization, and Monitoring**, the assessor will trace your implementation back to the catalogue reference (Control CA-9) and look for objective evidence on the latest two assessment cycles. ## How to implement #### Policy Management **Docs.** Keep each policy in version-controlled Markdown alongside the code that implements it; ship a signed PDF snapshot at each annual review and link the SHA into the SoA. ### Operational checklist - **Policy.** Document the trigger, the owner and the cadence. - **Security.** Document the trigger, the owner and the cadence. - **Internal.** Document the trigger, the owner and the cadence. - **Termination.** Document the trigger, the owner and the cadence. - **System.** Document the trigger, the owner and the cadence. - **Scope:** management, conditions, authorization, reviews, system, termination, assessment, system connections. ## Evidence to collect - **Policy Document.** A signed and version-controlled policy / standard / procedure document. Signed policy or standard documents the safeguard. Focus: Internal System Connections. ## Common pitfalls - Policies that no engineer has read; the version in Confluence drifts from the version that's actually being enforced. ## How it maps to other frameworks Computed from shared tags, control component and key-operation subjects — handy when you are reconciling controls across an audit. - [**HIPAA (45 CFR Part 164) 164.308(a)(3)(ii)(C)** — Workforce security - Establish Termination Procedures](https://support.icompaas.com/compliance/hipaa/164-308-a-3-ii-c-workforce-security-establish-termination-procedures) - [**ISO/IEC 27001:2022 A.8.26** — Application security requirements](https://support.icompaas.com/compliance/iso-27001-2022/a-8-26-application-security-requirements) - [**NIST SP 800-171 Rev. 3 3.12.1** — Security Assessment](https://support.icompaas.com/compliance/nist-sp-800-171-rev-3/3-12-1-security-assessment) - [**BSI C5:2020 SP-01** — Documentation, communication and provision of policies and instructions](https://support.icompaas.com/compliance/bsi-c5-2020/sp-01-documentation-communication-and-provision-of-policies-and-instructions) ## Related controls in NIST SP 800-53 Rev. 5 - [**Control CA-3** — Information Exchange](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ca-3-information-exchange) - [**Control CA-1** — Policy And Procedures](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ca-1-policy-and-procedures) - [**Control CA-6(1)** — Joint Authorization -- Intra-Organization](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ca-6-1-joint-authorization-intra-organization) - [**Control CA-6(2)** — Joint Authorization -- Inter-Organization](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ca-6-2-joint-authorization-inter-organization) - [**Control CA-7(4)** — Risk Monitoring](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ca-7-4-risk-monitoring) - [**Control CA-2(1)** — Independent Assessors](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5/ca-2-1-independent-assessors) ## References - [NIST Computer Security Resource Center — NIST SP 800-53 Rev. 5](https://csrc.nist.gov/Projects/risk-management/sp800-53-controls) - Catalogue identifier: `Control CA-9` Topics: governance riskpolicy management ## Related compliance guidance - [NIST SP 800-53 Rev. 5: a practical implementation guide for cloud teams](https://support.icompaas.com/compliance/nist-sp-800-53-rev-5): Start with the full NIST SP 800-53 implementation guide — scope, roadmap, evidence and how the assessment runs. - [NIST SP 800-171 and CMMC: a practical guide to protecting CUI in the cloud](https://support.icompaas.com/compliance/nist-sp-800-171-rev-3): If your obligation is protecting CUI in your own systems for a federal or defence contract, this derived subset — not the full catalogue — is the requirement. - [SOC 2 compliance: a practical implementation guide for cloud-native SaaS teams](https://support.icompaas.com/compliance/soc-2-trust-services-criteria): Most commercial SaaS already hold a SOC 2 Type 2, and FedRAMP 20x Class A is designed for providers that have one.