AB-900 on Microsoft Learn: study guide, learning path and practice assessment

The AB-900 study guide includes the audience profile, the three domains with their weights (Microsoft 365 services and objects 30–35%, data protection and governance 35–40%, administering Copilot and agents 25–30%) and the bullets that illustrate how each skill is assessed. It already shows the skills measured as of 14 October 2026 and a change log: there is only a minor adjustment in the security features sub-block.

The exam sandbox shows the real interface with generic content; ten minutes is enough. Official training, both the free learning path and the instructor-led course, is linked from the preparation section of the exam page on Microsoft Learn. The guide also recommends the Microsoft 365, Microsoft 365 Copilot, admin center and Purview documentation, and the Exam Readiness Zone series. The AB-900 outline breakdown helps you split the hours.

It launches from the certification page, it is free and Microsoft writes it, so the style, wording and difficulty resemble the exam. It lets you see the answer and rationale with a documentation link, and keeps a report of each attempt. Use it as a diagnosis at the start and again halfway through.

Its limits: the question set is finite and repeats, so by the third pass you are measuring memory. For daily work you need more volume and practice against the clock. The AB-900 practice test gives you tests by domain, an explanation on every question and 45-minute mock exams; free to start, no sign-up.

AB-900 does not require you to configure anything, but having seen the portals changes the outcome. With a free Microsoft 365 business trial you can walk through the Microsoft 365 admin center (users, groups, licences, domains), Exchange (mailboxes, distribution groups), SharePoint (sites, permissions, sharing), Teams (teams, policies) and Entra (conditional access, sign-in logs, Identity Secure Score).

For Purview, open the portal and locate every solution in the outline: sensitivity labels, DLP, retention, insider risk, communication compliance, DSPM for AI, eDiscovery, activity and data explorer, and Compliance Manager. You do not need real data: knowing where each thing lives and which question it answers is enough. Copilot features need a licence; if you do not have one, the Copilot and agent administration documentation includes screenshots of every screen.

Day 1: study guide, sandbox and the practice assessment as a diagnosis. Week 1: official training for the first domain and security, with the trial tenant open alongside. Week 2: Purview and data governance for Copilot, the heaviest block, and administering Copilot and agents. Last days: timed 45-minute mock exams and reviewing mistakes. The plan to pass AB-900 spells it out.

If you sit the exam after 14 October 2026, check the new version of the security sub-block in the study guide before your last week. And if you are unsure this is your certification, read who AB-900 is worth it for.