AB-900 cheat sheet

Updated September 28, 2026

Last-minute reference for AB-900. Data protection and governance is the largest domain; Copilot and agents is the smallest.

Exam facts

Duration45 minutes
Passing score700 / 1000
PriceSet per country or region; shown at booking
LevelFundamentals; does not expire
Outline versionAs of October 14, 2026

Skill areas

AreaWeight
Understand data protection and governance tasks for Microsoft 365 and Copilot35–40%
Identify the core features and objects of Microsoft 365 services30–35%
Perform basic administrative tasks for Copilot and agents25–30%

Requirement to tool

RequirementAnswer
Add a custom domainMicrosoft 365 admin center
Licences follow team membershipGroup-based licensing
One inbox, several usersShared mailbox
Email to every member’s own inboxDistribution group
Read-only access to a siteVisitors group
MFA only outside the officeConditional access with named locations
Why was a sign-in blocked?Entra sign-in logs
Who changed a role assignment?Entra audit logs
Admin roles only when neededPrivileged Identity Management
SSO for a gallery SaaS appEnterprise applications
One incident across email, identity and endpointDefender XDR
Encrypt a file wherever it goesSensitivity label with encryption
Block sensitive data being sent outDLP policy
Keep for seven years, then deleteRetention policy or label
Where is sensitive data stored?Data Explorer
What did users do with it?Activity explorer
Departing user exfiltrating dataInsider Risk Management
Harassment in chatsCommunication Compliance
AI use and sensitive promptsDSPM for AI
Regulatory score and actionsCompliance Manager
Find emails for a legal caseeDiscovery Content search
Sites shared too broadlyData access governance report
Limit a site to one groupRestricted access control (SAM)
Daily Copilot use in appsPer-user monthly licence
Occasional or agent-only usePay-as-you-go billing policy
Research report from many sourcesResearcher
Explain trends in spreadsheetsAnalyst
Copilot adoption numbersUsage reports, Copilot Analytics
Agent for one group onlyAgent settings, Microsoft 365 admin center
Copilot Studio environmentsPower Platform admin center

Zero Trust

Verify explicitly. Use least-privilege access. Assume breach.

Responsible AI

Fairness, reliability and safety, privacy and security, inclusiveness, transparency, accountability.

Traps

  • Copilot does not bypass permissions. It shows only what the user can already open; the fix is permissions, not Copilot.
  • Labels protect, retention keeps, DLP blocks. They are not interchangeable.
  • Data Explorer is where; activity explorer is what happened.
  • Insider Risk is behaviour; Communication Compliance is message content.
  • Distribution groups cannot carry licences.
  • App registration defines an app; the enterprise application is where you assign users.
  • Org-wide agents need approval before others can find them.
  • MS-900 material covers topics that are gone and misses Copilot entirely.

Night-before checklist

  • Name the three areas and which is largest
  • One sentence each on labels, DLP and retention
  • Why Copilot reveals oversharing, and three ways to reduce it
  • Monthly licence versus pay-as-you-go, cold
  • Check ID and proctoring rules; see exam day

Take the 20-question practice test and check your weakest area.