Microsoft retired Microsoft 365 Fundamentals and its exam, MS-900, on March 31, 2026, without naming an official replacement. The closest current fundamentals-level credential is Microsoft 365 Copilot and Agent Administration Fundamentals (exam AB-900), which covers Microsoft 365 administration with a focus on Copilot and agents.
Fundamentals certifications do not expire, so an MS-900 you already earned stays on your Microsoft Learn transcript.
Sources: Microsoft Learn: MS-900 study guide · Microsoft Q&A: MS-900 replacement
