IAM Users Are Dead: Modern AWS Access Control for 2025

IAM users once helped us bootstrap AWS environments, but in 2025 they are outdated and dangerous. This guide breaks down the risks, modern alternatives, and how to migrate securely—step by step.

Why IAM Users Are a Problem in 2025

Modern Alternatives to IAM Users

1. IAM Identity Center (Successor to AWS SSO)

Best for: Human access to AWS across accounts
Benefits:

• Integrates with IdPs like Google, Azure AD, Okta
• Manages permissions via centralized permission sets
• Enables SCIM provisioning and audit visibility

2. STS + AssumeRole for Automation

Best for: EC2, Lambda, and inter-service communication
Advantages:

• Credentials expire automatically
• Supports external ID and MFA
• No static secrets to manage

aws sts assume-role   --role-arn arn:aws:iam::123456789012:role/AutomationAccess   --role-session-name "devops-session"

3. OIDC Federation for CI/CD Pipelines

Best for: GitHub Actions, GitLab CI, Bitbucket
Advantages:

• No access keys stored in code
• Tight role scoping per repo/workflow
• Credentials rotate automatically

GitHub Actions Example:

jobs:
  deploy:
    permissions:
      id-token: write
      contents: read
    steps:
      - uses: aws-actions/configure-aws-credentials@v4
        with:
          role-to-assume: arn:aws:iam::123456789012:role/github-actions
          aws-region: us-east-1

Migration Roadmap

Phase 1: Discover Existing IAM Users and Usage

Before making changes, you need a clear picture of who’s using what.

Step 1: Generate a Credential Report

This report lists all IAM users in your account, their MFA status, and if they have active access keys.

aws iam generate-credential-report
aws iam get-credential-report --query Content --output text | base64 -d > credential-report.csv

Review this CSV file to identify:

• Users without MFA
• Users with long-standing credentials
• Unused accounts

Step 2: Map Use Cases

Group IAM users into categories:

• Human access → plan migration to Identity Center
• CI/CD and automation → migrate to STS or OIDC
• Legacy systems → evaluate and isolate

Phase 2: Replacement

• Replace human IAM users with IAM Identity Center
• Replace automated access with STS AssumeRole
• Reconfigure CI/CD pipelines to use OIDC federation

Phase 3: Cleanup

Make sure that, for all migrated users, there are no remaining credentials

If You Must Keep IAM Users…

If you have legacy apps that require IAM users:

• Enforce MFA
• Rotate access keys automatically
• Monitor with CloudTrail and GuardDuty

Final Thoughts

IAM users served their time—but in 2025, they are no longer secure or scalable.

By transitioning to Identity Center for users, STS for automation, and OIDC for pipelines, you’re moving toward a modern, zero-trust access model that scales with your org.

Let IAM users rest in peace. Your future is federated. 🔐