CertifyDeckThe official AB-900 page warns that the English version of the exam will be updated on 14 October 2026. If you have the exam booked, the question is whether you need to study again. The short answer is no: we compared the new outline with the current one line by line and the change is minimal.
What Microsoft says
The page for the Microsoft 365 Certified: Copilot and Agent Administration Fundamentals certification carries a notice that the English version is updated on 14 October 2026 and points to the study guide. The guide, updated on 14 September, already shows the outline under the heading "Skills measured as of October 14, 2026".
At the end of the guide, the change log compares the previous version with the new one. The audience profile and the domain on Microsoft 365 objects and features appear as unchanged, and only the block "Identify the core security features of Microsoft 365 services" is listed with a minor change.
The line-by-line comparison
We put the 22 July 2026 outline, which is the current one, next to the 14 October outline. Both versions have the same blocks and the same objectives. The only different line is in the security block: the objective on application registrations read "App registrations and Enterprise apps" and now reads "App registrations and Enterprise applications".
It is a naming adjustment. The concept being assessed is the same: understanding what an app registration is and what an enterprise application is in Microsoft Entra ID.
The three domains, which do not change
Identify the core features and objects of Microsoft 365 services (30–35%): licensing, the Microsoft 365, Exchange, SharePoint and Teams admin centers, security principles, Microsoft Entra ID, Conditional Access, single sign-on, audit and PIM.
Understand data protection and governance tasks for Microsoft 365 and Copilot (35–40%): Microsoft Purview, the data security implications of Copilot, compliance risks and SharePoint oversharing. And perform basic administrative tasks for Copilot and agents (25–30%): licensing, pay-as-you-go billing, adoption, prompts and agent lifecycle. The detail is in the AB-900 outline.
What to do if you have the exam booked
Do not move your date because of this change. Whether you sit the exam before or after 14 October, the content is the same and the plan to pass AB-900 still applies as it is.
The CertifyDeck AB-900 practice questions follow the 22 July outline, which matches the 14 October one in content, so they need no changes. If you sit a localized version, it will be updated about eight weeks later, with the same result.
Not every October change is like this
Check exam by exam. AB-730, updated on 20 October, does change substantially: it goes from three domains to four and adds prebuilt agents and Microsoft Copilot Cowork. We explain it in AB-730 changes on 20 October 2026.
The way to find out is always the same: open the official study guide, look at the date in the "Skills measured as of" heading and read the change log at the end, which states block by block whether the change is major, minor or none.
Frequently asked questions
Does exam AB-900 change in October 2026?
Yes, the English version is updated on 14 October 2026, but the change is minimal: the three domains and their weights stay the same, and Microsoft marks only one block with a minor change.
Do I need to study anything new for AB-900?
No. Comparing both versions of the outline, the only difference is the wording of one objective in the security block: "Enterprise apps" becomes "Enterprise applications". The assessed content is the same.
When do localized versions of AB-900 change?
Microsoft updates the English version first and localized ones about eight weeks later. For the 14 October change that points to mid-December, with no official date.
Should I bring my exam forward or push it back?
Not because of this change. Choose the date based on your preparation: the outline has the same content before and after 14 October 2026.