Should organisations manage machine identities inside IAM, IGA, or PAM programmes?

How machine identities should be split across IAM, IGA, and PAM

Machine identities are not a single-programme problem. IAM owns how they authenticate and what scopes or roles they receive, IGA owns how they are inventoried, reviewed, attested, and retired, and PAM owns elevated or high-risk access that must be tightly controlled, vaulted, or time-bound. That split prevents one team from assuming another has lifecycle or privilege covered.

The practical question is not which programme “owns” machine identities in the abstract, but which control plane is responsible for each decision. IAM is the enforcement point for runtime access, IGA is the governance point for inventory and review, and PAM is the exception path for powerful access that needs stronger controls than ordinary service access.

That separation matters because machine identities behave like credentials with a lifecycle, not just like users with a different label. When teams collapse them into one programme, they usually miss one of three things: who can create or approve them, who can attest that they still need access, or who can constrain them when privilege is high. Our IAM and IGA Basics guide frames that split clearly, and the Service Account Security Guide shows why service accounts need both governance and enforcement, not just one or the other.

Why a shared model works better than single ownership

Shared governance is the right model because the control objective changes as the machine identity moves through its life. At creation time you need proof of purpose and ownership. During steady state you need authentication, least privilege, and scope control. At review time you need recertification and dependency checks. At retirement time you need revocation, rotation, and safe decommissioning.

If IAM is treated as the only home, the environment can end up with active credentials that nobody reviews. If IGA is treated as the only home, the organisation may know the identity exists but still lack strong runtime enforcement. If PAM is treated as the only home, the team may over-focus on privileged exceptions and ignore ordinary machine access that still carries material risk. The better model is coordinated ownership with one programme doing lifecycle governance, one doing access enforcement, and one doing privilege containment.

This is also where workload and service identities need clear placement. A machine identity may be managed differently from a human account, but it still needs a defined owner, an approval path, and a way to prove that its access remains justified. For broader machine-identity governance patterns, Ultimate Guide to NHIs provides the parent concept, while the NHI Lifecycle Management Guide is useful when the key concern is provisioning, rotation, and offboarding over time.

Where the boundaries should sit in practice

IAM should handle authentication methods, identity sources, scopes, and policy enforcement for normal machine-to-machine access. IGA should maintain the authoritative inventory, map business ownership, run access reviews, and confirm whether the identity still has a valid use case. PAM should cover any elevated access path, including admin tokens, break-glass use, vaulting, session control, and just-in-time elevation where the access can materially change systems or data.

That boundary is easiest to maintain when the organisation treats “machine identity” and “privileged machine identity” differently. A routine integration account that calls a narrow API should not be governed like a root-level automation identity. The moment a service can alter production, read sensitive vault content, or impersonate higher-trust systems, PAM controls become part of the design rather than an afterthought. Privileged Access Management Guide is the clearest reference point for that distinction.

The same model also helps with evidence. IAM should be able to show what authenticated, IGA should be able to show who approved and reviewed it, and PAM should be able to show how elevation was constrained. If those proofs live in separate teams but are not connected, the organisation can still have strong controls and weak assurance. That is why Access Reviews and Certification Guide is a useful companion when machine identities are part of the review population.

Risk and Threat Considerations

When machine identities are split across programmes without clear boundaries, the common failure is control drift: an identity is created in IAM, forgotten in IGA, and left with privilege that PAM never sees. That is exactly how stale service accounts, unmanaged tokens, and overprivileged automation become long-lived attack paths.

Failure mechanism: Weak ownership lets the lifecycle, access, and privilege decisions diverge, so revocation, review, and escalation controls no longer line up with the real account usage.

Impact: Attackers or internal misuse can persist through dormant credentials, expand access through excess privilege, or abuse elevated machine access to reach sensitive systems and data.

Practitioner Guidance

What to prioritise: Start by assigning one accountable owner for lifecycle, one for runtime access policy, and one for privileged exceptions. If those three roles are not explicit, the programme will default to “everyone and no one,” which is where machine identities usually fail.

What to verify: Check whether every machine identity has a named business purpose, a renewal or expiry rule, an access review path, and a documented trigger for PAM escalation. If any one of those is missing, the control model is incomplete even if the identity technically works.

Practitioner takeaway: The safest operating model is not one master programme, but clear division of labour with one authoritative lifecycle view, one enforcement layer, and one privileged-access gate.

Related resources from NHI Mgmt Group

• How should organisations govern non-human identities inside IGA programmes?
• How can organisations reduce the blast radius of compromised agent identities?
• What does the 144:1 NHI-to-human ratio mean for IAM governance programmes?
• What is the difference between IAM and PAM for machine identities?