What is AWS Identity and Access Management (IAM)?

What is AWS Identity and Access Management (IAM)?

AWS Identity and Access Management (IAM) enables you to manage access to AWS services and resources securely. IAM gives you the flexibility to


8 min read

The vast potential of the cloud comes with a crucial responsibility: security. AWS IAM provides a centralized platform for managing user identities and controlling their access to AWS services and resources. It provides a way to create and manage users, groups, roles, and policies that determine who can do what, where, and when in your AWS account.

Imagine your AWS account as a digital fortress. IAM acts as the gatekeeper, meticulously determining who (users, applications, services) can access what resources (S3 buckets, EC2 instances, etc.), when (temporary or long-term access), and under what conditions (specific actions allowed by permissions).

Key Components of AWS IAM

  1. IAM Users: IAM allows you to create individual users with unique credentials, enabling them to access AWS resources securely. Each user can have specific permissions assigned to them based on their role within the organization.

  2. IAM Groups: Groups in IAM simplify permission management by allowing you to organize users with similar access requirements. Instead of assigning permissions to individual users, you can assign them to groups, streamlining the process of access management.

  3. IAM Roles: IAM roles are entities with permissions that can be assumed by users, applications, or services within your AWS environment. Roles provide temporary access to resources and are commonly used for cross-account access, federated access, and granting permissions to AWS services.

  4. IAM Policies: IAM policies define the permissions that are granted or denied to users, groups, or roles. Policies are JSON documents that specify the actions users can perform and the resources they can access. By adhering to the principle of least privilege, you can ensure that users have only the permissions necessary to perform their tasks.

Benefits of AWS IAM

  • Granular Access Control: IAM enables you to define fine-grained permissions, allowing you to grant only the necessary level of access to resources.

  • Security: By following the principle of least privilege, IAM helps reduce the risk of unauthorized access and data breaches.

  • Flexibility: IAM supports a wide range of use cases, from managing users and groups to granting temporary access through roles.

  • Compliance: IAM features such as access logging and identity federation help organizations maintain compliance with regulatory requirements.

1. AWS Root User Account

The AWS Root User Account is the initial account created when you sign up for AWS services. It has complete access to all AWS services and resources within the account. The root user has full administrative privileges, including the ability to manage billing, change account settings, and create or delete IAM users and roles. However, it's important to note that using the root user account for everyday tasks is not recommended due to security and management reasons.

Best Practices for AWS Root Account

  1. Secure credentials with strong passwords and Multi-Factor Authentication (MFA).

  2. Limit its use to essential administrative tasks only.

  3. Enable MFA for added security.

  4. Create IAM users with least privileges for routine tasks.

  5. Use IAM roles for elevated access when necessary.

  6. Monitor root user activity with AWS CloudTrail.

  7. Consider using AWS Organizations for managing multiple accounts centrally.

2. AWS IAM Users

An IAM user is an identity that you create in AWS. It represents the person or application that interacts with AWS services and resources. It consists of a name and credentials. Unlike the root user with full access, IAM user accounts provide a secure way to grant granular permissions based on specific needs.

By default, when you create a new IAM user in AWS, it has no permissions associated with it. To allow the IAM user to perform specific actions in AWS, such as launching an Amazon EC2 instance or creating an Amazon S3 bucket, you must grant the IAM user the necessary permissions.

Best Practices for AWS IAM Users

  • Individual Accounts: AWS recommend that you create individual IAM users for each person who needs to access AWS. Even if you have multiple employees who require the same level of access, you should create individual IAM users for each of them. This provides additional security by allowing each IAM user to have a unique set of security credentials.

  • Implement Least Privilege: Assign permissions based on least privilege to limit access to only what's necessary.

  • Monitor User Activity: Enable CloudTrail logging for IAM events to monitor user actions and detect anomalies.

  • Enforce Password Policies: Implement strong password policies like minimum length, complexity requirements, and regular rotation.

  • Disable or Delete Unused Accounts: Regularly review your IAM users and deactivate or delete any unused accounts to minimize the attack surface.

  • Enable Multi-Factor Authentication (MFA): Enhance security by requiring MFA for IAM user accounts.

  • Utilize IAM Groups (Optional): For IAM Users with similar permission requirements, create IAM groups and assign user accounts to those groups. This simplifies permission management.

3. AWS IAM Policy

AWS IAM Policy is a JSON document that defines permissions and access controls for AWS Identity and Access Management (IAM) users, groups, or roles. These policies specify what actions are allowed or denied on which AWS resources.

Best Practices for AWS IAM Policies

  • Use Least Privilege: Grant only necessary permissions.

  • Leverage Managed Policies: Utilize AWS-managed policies whenever possible, as they are maintained by AWS and automatically updated to reflect best practices and new features. Managed policies help ensure consistency and compliance with security standards.

  • Avoid Wildcards (*): Refrain from using wildcard (*) actions in IAM policies whenever possible, as they grant overly broad permissions and increase the risk of unauthorized access. Instead, specify only the actions required for the specific task.

  • Enable Versioning and Logging: Maintain policy history and monitor changes.

  • Test with IAM Policy Simulator: Before deploying IAM policies in a production environment, use the IAM Policy Simulator to test and validate their effectiveness. The simulator helps identify potential issues and ensure policies behave as intended before implementation.

  • Utilize Policy Variables: Create dynamic policies for flexible access control.

  • Regularly Audit Policies: Remove unnecessary permissions and outdated policies.

  • Enable Access Analyzer: Continuously monitor for unintended access and policy issues.

4. AWS IAM Groups

AWS IAM Groups are a way to organize IAM users and manage their permissions collectively. Instead of attaching permissions directly to individual users, you can assign permissions to groups, making it easier to manage access control in a scalable and efficient manner.

Best Practices for AWS IAM Groups

  • Organize Users by Access Needs: Group users with similar permissions together.

  • Apply Least Privilege: Grant only necessary permissions to groups.

  • Use Managed Policies: Utilize AWS-managed policies for consistent permissions.

  • Avoid Overlapping Permissions: Ensure users are only in groups that align with their roles.

  • Regularly Review Group Membership: Periodically review and update group memberships.

  • Combine with IAM Policies: Use IAM policies for fine-grained access control.

  • Establish Naming Conventions: Use consistent naming for easy identification and management.

  • Document Policies and Membership: Document permissions and group memberships for auditing.

  • Consider Cross-Account Access: Centralize permissions management for multiple accounts.

5. AWS IAM Roles

AWS IAM Roles are entities in AWS Identity and Access Management (IAM) that define a set of permissions and policies. Unlike users or groups, roles are not associated with specific individuals or resources. Instead, they are intended to be assumed by IAM users, AWS services, or external entities, allowing them to temporarily inherit the permissions associated with the role.

Best Practices for AWS IAM Roles

  1. Grant access temporarily: IAM roles are ideal for situations in which access to services or resources needs to be granted temporarily, instead of long-term.

  2. Cross-Account Access: Use roles to grant access between AWS accounts.

  3. Avoid Long-Term Credentials: Utilize roles instead of long-term access keys. Roles provide temporary credentials that automatically rotate, reducing the risk of credential compromise.

  4. IAM Roles for AWS Services: Assign roles to AWS services for dynamic permissions.

  5. Role-Based Access Control (RBAC): Follow the least privilege principles when defining role permissions.

  6. IAM Role Tags: Use tags for efficient role management. Tags can be used for cost allocation, access control, and resource management purposes, providing additional context and organization.

  7. IAM Permission Boundaries: Use IAM permission boundaries to limit the maximum permissions that can be granted by an IAM role. Permission boundaries help enforce security policies and prevent users from escalating privileges beyond their intended scope.

  8. Regular Credential Rotation: Rotate credentials associated with IAM roles, such as temporary security tokens or session tokens, regularly to mitigate the risk of unauthorized access due to compromised credentials.

  9. Enable CloudTrail Logging: Enable AWS CloudTrail logging for IAM role activity to monitor and audit role assumptions and actions performed by users or services. CloudTrail provides detailed logs of API calls made by IAM roles, aiding in security analysis and compliance efforts.


AWS IAM is a critical component of AWS security, providing a robust framework for managing access to resources in the cloud. By following best practices and leveraging the features of IAM, organizations can enhance security, enforce compliance, and maintain control over their AWS environment. Whether you're a small startup or a large enterprise, understanding and effectively implementing AWS IAM is essential for securing your cloud infrastructure.

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