Category: Governance Roles

Authorizing Official

Also known as: AO, Approving Official

Simply put

An Authorizing Official is a senior government official or executive who has the authority to formally approve the operation of an information system after weighing its security risks. By granting this approval, the official personally accepts responsibility for running the system at a level of risk considered acceptable to the organization. Note that the acronym "AO" can also refer to an "Approving Official" in the distinct context of government purchase and travel card programs.

Formal definition

In the context of federal information system risk management, the Authorizing Official (AO) is a senior Federal official or executive with the authority to formally assume responsibility for operating an information system at an acceptable level of risk. The AO generally serves as the principal decision maker in system risk management and risk assessment activities, and functions as the chief reviewer who determines whether identified risk is acceptable prior to authorization. Because risk cannot be entirely eliminated, the AO's decision reflects an explicit acceptance of residual risk. Readers should note that an authorization decision is typically time-bound and subject to continuous monitoring rather than permanent, and that specific AO duties, delegation, and appointment criteria may vary by agency and by governing framework (for example, DoD implementations may impose additional requirements). Verify current authoritative text, as this entry does not cover implementation or agency-specific procedural details.

Why it matters

The Authorizing Official is the individual who personally accepts responsibility for operating an information system at a given level of risk. This makes the AO a pivotal accountability point in federal risk management: rather than diffusing responsibility across a team, the framework concentrates the ultimate authorization decision in a single senior official who must weigh identified risks and formally accept the residual risk that remains after safeguards are applied. Because risk can never be entirely eliminated, the AO's signature represents an explicit, documented judgment that remaining risk is acceptable to the organization.

A critical point for practitioners is that an authorization decision is time-bound and subject to continuous monitoring rather than permanent. An Authority to Operate (ATO) is not a one-time clearance that persists indefinitely; the AO's acceptance of risk is conditioned on the system's security posture remaining within acceptable bounds over time. Confusing authorization with assessment, or treating an ATO as a permanent grant, misrepresents the AO's role and the ongoing nature of the accountability being assumed.

Readers should also note a terminology hazard: the acronym "AO" is used in an entirely separate context to mean "Approving Official" within government purchase and travel card programs, where an Approving Official (typically a supervisor) oversees cardholder transactions. That role is unrelated to information system risk authorization, and conflating the two can cause meaningful confusion in documentation and communications.

Who it's relevant to

Authorizing Officials and senior executives

Senior federal officials or executives who hold, or may be appointed to, the AO role need to understand that authorizing a system means personally assuming responsibility for operating it at an accepted level of risk. This accountability is time-bound and tied to continuous monitoring, so it does not end at the moment authorization is granted.

Information System Security Managers and risk practitioners

Those who prepare and present risk information for authorization decisions support the AO in the role of chief reviewer and decision maker. They should ensure risk assessment materials clearly communicate identified risks and residual risk so the AO can make an informed acceptance decision.

DoD compliance and program staff

Personnel working under DoD implementations should be aware that DoD may impose additional AO requirements beyond general federal guidance. They should confirm the specific duties, delegation rules, and appointment criteria against current authoritative DoD text rather than relying on generic federal descriptions.

Purchase and travel card program staff

Individuals working with government purchase and travel card programs should recognize that in their context the acronym "AO" refers to an Approving Official, a distinct role typically held by a supervisor, and not to the information system Authorizing Official described here.

Inside AO

Accountability for Risk Acceptance

The Authorizing Official (AO) is the senior federal official or executive with the authority to formally assume responsibility for operating an information system at an acceptable level of risk to organizational operations, assets, individuals, and other organizations. Under the NIST Risk Management Framework (RMF), described in NIST SP 800-37 as of the applicable revision, this role is generally reserved to a government official rather than a contractor.

Authorization Decision

The AO renders the authorization decision, most commonly an Authority to Operate (ATO). Depending on the results of the security assessment and residual risk, the outcome may also take other forms recognized under RMF guidance, such as a denial of authorization or a conditional or time-limited authorization. Readers should verify the current authorization decision types against the applicable revision of the governing guidance.

Review of the Authorization Package

The AO's decision is informed by the authorization package, which generally includes the system security plan, the security assessment report prepared by an assessor, and the plan of action and milestones (POA&M) addressing identified weaknesses. The AO weighs residual risk against mission needs before deciding.

Continuous Monitoring Oversight

An authorization is time-bound and subject to ongoing risk determination. The AO retains responsibility for reviewing continuous monitoring results throughout the authorization period and may reconsider or withdraw an authorization if the risk posture changes.

Scope and Applicable Authority

The AO role appears across federal civilian systems under FISMA and DoD systems operating under the RMF. Specific designation, delegation rules, and titles can vary by agency and by community (for example, national security systems may follow additional or differing requirements), so the governing authority for a given system should be confirmed.

Common questions

Answers to the questions practitioners most commonly ask about AO.

Is an Authority to Operate (ATO) granted by an Authorizing Official permanent?

No. An ATO is a time-bound decision, not a permanent authorization. The Authorizing Official (AO) accepts risk for a defined period and the authorization remains contingent on continuous monitoring of the system's security posture. Changes to the system, its environment, or its risk profile can require reassessment or reauthorization before the authorization term expires. Readers should confirm specific authorization terms and continuous monitoring expectations against the applicable RMF guidance and their agency's policy, which may vary.

Does the Authorizing Official's issuance of an ATO mean the system is fully secure and compliant?

Not necessarily. An AO's authorization is a formal risk-acceptance decision, not a certification that a system is secure or that compliance equals security. The AO may authorize a system while accepting known residual risks, often documented in a plan of action and milestones. Authorization reflects a judgment that residual risk is acceptable for the mission or business function, not that all vulnerabilities have been eliminated. Verify the scope and conditions of any authorization decision against the supporting authorization package and agency policy.

Who can serve as an Authorizing Official, and can the role be delegated?

The AO is generally a senior official with the authority to formally assume responsibility for operating an information system at an acceptable level of risk. In many implementations, aspects of the role may be supported by a designated representative who coordinates activities but does not, in most cases, hold final authorization authority. The precise eligibility criteria, seniority requirements, and delegation limits are set by governing RMF guidance and agency-specific policy, which the reader should confirm for their organization and system type.

What information does an Authorizing Official rely on to make an authorization decision?

An AO generally reviews the authorization package, which typically includes the system security plan, the security assessment report produced during the assessment step, and the plan of action and milestones. These materials help the AO understand the security control implementation, assessment findings, and outstanding risks. Note that assessment and authorization are distinct steps: the assessor evaluates controls, while the AO makes the risk-based decision. The exact contents and format of the package should be confirmed against current authoritative RMF guidance and agency requirements.

How does the Authorizing Official's role differ for DoD systems versus federal civilian systems?

The AO function exists across federal civilian agencies under FISMA and DoD systems under the RMF, but scope, terminology, and reporting relationships can differ by domain. Systems handling different information categories, such as Controlled Unclassified Information or national security information, may carry different authorization expectations. A FedRAMP authorization for a cloud service does not automatically satisfy a DoD AO's authorization requirements. Readers should confirm the applicable authorization boundaries and requirements for their specific system category against current governing policy.

What are the Authorizing Official's responsibilities after an ATO is issued?

After authorization, the AO generally retains responsibility for the ongoing risk posture of the system through continuous monitoring. This includes staying informed of changes to the system and its threat environment, reviewing monitoring results, and determining whether accepted risk remains acceptable or whether reassessment or reauthorization is warranted. The specific continuous monitoring cadence, reporting obligations, and triggers for reauthorization should be verified against applicable RMF guidance and agency policy.

Common misconceptions

An Authority to Operate (ATO) granted by the AO is permanent.

An ATO is time-bound and remains contingent on continuous monitoring. The AO can reconsider or withdraw the authorization if the risk posture changes, and reauthorization is generally required as conditions or timeframes dictate under the applicable RMF guidance.

The assessor who evaluates the system also authorizes it.

Assessment and authorization are distinct functions. The assessor produces the security assessment report evaluating control effectiveness, while the AO makes the separate risk-based authorization decision. Combining these roles undermines the independence intended by the RMF process.

The AO role can be filled by a contractor.

The AO is generally a senior government official who accepts risk on behalf of the organization. This accountability for risk acceptance is typically reserved to a federal official rather than delegated to a contractor, though specific delegation rules should be verified against agency policy and the applicable revision of the governing guidance.

Best practices

Treat every authorization as time-bound and tie the authorization decision to a defined continuous monitoring strategy rather than a one-time review.

Ensure the assessor and authorizing official remain separate to preserve the independence of assessment from authorization.

Base the authorization decision on a complete authorization package, including the system security plan, security assessment report, and plan of action and milestones (POA&M).

Document the residual risk considered and the rationale for the decision so the basis for accepting risk is traceable.

Confirm the AO designation, delegation rules, and applicable authority for the specific system community (for example, federal civilian under FISMA versus DoD under RMF, or national security systems) before relying on generalized role descriptions.

Reassess authorization when continuous monitoring results indicate a material change in the system's risk posture rather than waiting solely for a scheduled reauthorization.