TL;DR: What Does ATO Stand for in RMF?

An Authorization to Operate (ATO) is a formal decision by an Authorizing Official (AO) that a system meets security and privacy requirements and may operate at an acceptable level of risk, as defined by the NIST Risk Management Framework (RMF). It is not a certification of compliance but a risk-based approval based on documentation and assessments.

While traditional ATOs are time-bound and slow, the Continuous ATO (cATO) model—developed by the Department of Defense—enables faster, more secure software delivery through continuous monitoring, automated risk analysis, and delegated authority. It builds on NIST’s concept of ongoing authorization but formalizes it with real-time telemetry, control gates, and risk thresholds.

Organizations like Rise8 refer to their implementation of this approach as the Continuous Delivery–Risk Management Framework (CD-RMF)—an agile, DevSecOps-aligned method for delivering compliant software at speed.

What Is an ATO in RMF?

Authorization to Operate (ATO) is a product of the National Institute of Standards and Technology (NIST) Risk Management Framework (RMF) so they are often referenced together.

The RMF outlines a structured, but adaptable process with seven steps for managing risks associated with information systems: prepare, categorize, select, implement, assess, authorize, and monitor. Organizations may apply these steps in non-sequential order, as applicable to their software development lifecycles. ATOs are always for government information systems, but the meaning in a business context is no different.

Top Uses for an ATO‍

An Authorization to Operate (ATO) provides formal assurance that a system can operate on a government network at an acceptable level of risk. In practice, teams use an ATO to:

1. Manage risk: Identify, document, and reduce security and privacy risks so systems can operate safely.
2. Prove compliance: Demonstrate that systems meet FISMA and agency-specific security requirements.
3. Authorize deployment: Secure official permission to launch and operate systems in federal environments.
4. Support incident response: Define how security issues will be detected, reported, and mitigated.
5. Maintain operational integrity: Ensure the system continues to perform its mission securely and reliably over time.

Traditional ATOs, however, are slow and resource-intensive. They rely on static, point-in-time assessments and extensive documentation—delaying critical capabilities by months or even years. With three-year validity windows and reauthorization required for major updates, it’s increasingly difficult to keep up with evolving threats and technology.

What Are the Seven Steps of the RMF Process?

The RMF ATO process consists of seven essential steps that organizations may apply in nonsequential order:

1. Prepare: Identify key risk management roles, establish the organizational risk management strategy, and conduct risk assessments.
2. Categorize: Categorize systems and the information they process based on the potential impact of a security breach.
3. Select: Choose appropriate security controls from NIST SP 800-53 based on the categorization and risk assessments.
4. Implement: Implement the selected security controls and properly document them.
5. Assess: Assess the effectiveness of the implemented controls to ensure they function as intended and manage the risk effectively.‍
6. Authorize: A senior official reviews the security risks and decides whether the system or controls have an acceptable level of risk to operate resulting in an ATO.‍
7. Monitor: Conduct continuous controls monitoring to ensure they remain effective and the system stays secure over time.

These ATO process steps are essential to maintain ongoing situational awareness for risk management decisions on information systems’ security and privacy posture.

Note: This list is a high-level overview of the RMF process—multiple steps in each section must be completed. More information is available on NIST's website or when working with an experienced partner like Rise8.

How Long Does the ATO Process Take?

While the time required to obtain an ATO varies from six months to two years, many identify working through the assessments as the longest step in developing and deploying software. An ATO granted during the seven-step RMF process requires a point-in-time check of security controls that can take months; the exercise repeats for major updates. Several factors contribute to process timeliness, including system complexity, the thoroughness of the preparation and documentation, the responsiveness of all stakeholders, and the availability of technically skilled assessors and highly competent system development teams.

Notably, an ATO is issued for a limited period, typically three years, and requires reauthorization once it expires. This periodic reassessment can be resource-intensive and disruptive, leading to delays and potential security gaps. The Department of Defense (DOD) ATO process highlights these challenges, emphasizing the need for a more dynamic and continuous approach to maintain security and operational efficiency.

cATO is an ongoing authorization for continuous delivery after achieving the initial authorization. It allows an organization to build and release new system capabilities if it can continuously monitor them against the approved security controls. To achieve cATO, DoD identifies three criteria organizations must meet:

• Continuous monitoring of security controls.
• Active cyber defense measures.
• The adoption of DevSecOps practices.

Shifting from periodic reviews to constant monitoring avoids drifting out of compliance and creates a more robust cybersecurity posture. cATO is not a waiver or a shortcut to compliance with the RMF. Instead, the method tackles requirements at every step of the software development lifecycle to reduce risk.

Ship Software. Save Lives.

Rise8 is at the forefront of continuous Authorization to Operate, pioneering its application in federal settings. By employing strategies for continuous delivery, Rise8 helps organizations deploy secure, compliant, and timely software. Our approach to continuous authorization reduces the need for repeated, time-consuming reauthorizations under the traditional ATO framework. This allows for more agile and responsive operations, better aligned with the fast-paced demands of modern cybersecurity.

The Rise8 cATO playbook, can help you start making impactful changes today. Together, we can ship game-changing software so that fewer bad things happen because of bad software.