CertifyDeckMS-900 retired on March 31, 2026 and can no longer be scheduled; the date appears on Microsoft Learn's official list of retired exams. The Microsoft 365 fundamentals exam that takes its place is AB-900, Microsoft 365 Copilot and Agent Administration Fundamentals. It is not merely a new exam code: it shifts the focus from broad Microsoft 365 business value to administering, securing and governing Copilot and agents.
What AB-900 provides
AB-900 covers supporting, securing and protecting Microsoft 365 Copilot and agents. It includes admin centers, identity, Conditional Access, Defender XDR, audit, Purview, SharePoint oversharing, licensing, billing, adoption and agent lifecycle.
It fits entry-level administrators, support engineers and IT pros beginning to own enterprise AI controls before broader deployment.
What MS-900 covered
MS-900 covered broad Microsoft 365 fundamentals: cloud services, productivity and collaboration, high-level security and compliance, licensing, support and business value.
The exam and credential retired on March 31, 2026. Its learning material can still provide vocabulary, but it should not be treated as a bookable certification or as complete preparation for AB-900.
What to do if you were studying MS-900
Do not buy a course or test that promises entry to MS-900; the exam is no longer available. Keep the foundations on users, groups, Teams, SharePoint, identity and licensing, then compare your notes with the official AB-900 outline.
Add operational Purview, Microsoft Graph, Copilot data security, SharePoint oversharing, DSPM for AI, Copilot licensing and agent lifecycle administration. Generic legacy material does not cover those areas deeply enough.
Use the overlap efficiently
The outlines overlap on core services, identity, security, compliance and licensing. Reuse that foundation, but treat AB-900 as a new preparation path aligned with the AI-enabled Microsoft 365 environment.
Take an AB-900 diagnostic before setting your plan. General-concept gaps suggest foundation work; governance-tool gaps point to Purview, SharePoint and agent administration.
Frequently asked questions
What is the replacement for MS-900?
AB-900, Microsoft 365 Copilot and Agent Administration Fundamentals. It is the closest current path after MS-900's retirement, although it shifts the focus toward Copilot and agent administration rather than reproducing the old outline.
Is my MS-900 certification still valid?
Yes. A retired certification stays on your Microsoft Learn transcript with the date you earned it. What you can no longer do is sit the exam.
Can I still take MS-900?
No. Microsoft retired MS-900 on March 31, 2026, and the exam can no longer be scheduled.
Can I reuse my MS-900 notes?
Yes, for core services, identity, security and licensing. Add Purview, Microsoft Graph, Copilot security, oversharing and agent administration.