Authorization to Operate (ATO) is the formal decision by an authorizing official to allow an information system to operate after reviewing its security and privacy controls and accepting the remaining risk.
An Authorization to Operate, commonly called an ATO, is used within the U.S. federal government to confirm that the risks associated with operating an information system have been reviewed and accepted. The authorization applies within a defined environment and may include specific terms and conditions for how the system operates.
ATO is closely tied to the NIST Risk Management Framework (RMF), which provides a structured approach to identifying risks, implementing controls, assessing their effectiveness, authorizing systems, and continuously monitoring them. An ATO is therefore not simply proof that a checklist has been completed. It represents an explicit decision to accept the risk associated with operating the system.
The terms authorization to operate and authority to operate are sometimes used interchangeably. However, Authorization to Operate is the terminology used by NIST for the formal authorization decision.
For federal agencies and organizations supporting federal systems, an ATO provides documented assurance that security and privacy risks have been evaluated and appropriate risk mitigation measures have been considered before a system is approved for operation.
The ATO cybersecurity process helps organizations:
An ATO does not mean a system is risk-free. Instead, it means the responsible authorizing official has reviewed the available evidence and formally accepted the remaining risk under defined terms and conditions.
The authorization to operate process generally follows the NIST Risk Management Framework (RMF), from defining the system and its risks to authorization and ongoing monitoring. Exact requirements can vary by agency, system, impact level, and federal requirements. Here are the key stages of the ATO process:
Define the system, its authorization boundary, the information it handles, and its operating environment. The system is then categorized based on the potential impact of a security incident.
Identify the security and privacy controls needed based on the system’s risk profile. These controls support risk management and protect the system.
Put the selected controls in place and document how they work, including who is responsible for each control and how it will be managed and maintained over time.
Perform ATO testing to check whether controls are implemented correctly and working as intended. Collect evidence and identify any weaknesses that need to be addressed.
The authorizing official reviews the assessment findings and remaining risks. They then decide whether the risk is acceptable and the system can be authorized to operate.
Continue monitoring controls, vulnerabilities, system changes, and risks after authorization. This helps identify changes that could affect the system’s security posture.
| Stage | Main action | Purpose |
| Prepare & categorize | Define and categorize the system | Understand impact and risk |
| Select | Choose required controls | Establish safeguards |
| Implement | Apply and document controls | Put protections in place |
| Assess | Test controls and evidence | Identify weaknesses |
| Authorize | Review and accept risk | Approve operation |
| Monitor | Track controls and changes | Maintain security over time |
ATO testing assesses the security and privacy controls that support an authorization decision. It determines whether controls are implemented correctly, working as intended, and providing the expected level of protection. The results give the authorizing official evidence to evaluate the system’s remaining risk.
Testing can include reviewing policies and procedures, examining system configurations, interviewing control owners, checking evidence, and performing technical security assessments. Any weaknesses identified during testing may need to be remediated or documented and tracked through a Plan of Action and Milestones (POA&M).
Testing and monitoring remain important after an ATO is issued. As systems and risks change over time, continuous compliance and continuous security monitoring help ensure controls remain effective. Automated compliance monitoring can help teams maintain current evidence, identify control issues earlier, and track remediation over time.
FedRAMP and ATOs are closely connected, but a FedRAMP authorization to operate is not simply another name for FedRAMP authorization. FedRAMP provides a standardized approach for assessing and authorizing cloud services used by federal agencies, helping establish consistent security requirements and reusable assessment evidence.
This evidence can support an agency’s authorization to operate process and reduce duplicated assessment work. However, the agency’s authorizing official is still responsible for deciding whether the remaining risk associated with its specific system and use of the cloud service is acceptable.
Scytale helps organizations streamline the work that supports the authorization to operate process. Automated evidence collection, continuous control monitoring, and centralized compliance management make it easier to maintain documentation, track controls, identify gaps, and keep evidence up to date.
Instead of relying on manual, point-in-time compliance work, teams can maintain visibility into their security posture and address issues as they arise. Scytale also pairs its platform with dedicated GRC experts who help teams understand requirements, review evidence, address compliance challenges, and stay on track with their broader compliance program.
