TL;DR
Microsoft AB-400 (Power Platform Developer Associate) opens for registration on October 16, 2026 and replaces PL-400. Domain 3, Extend Microsoft Power Platform, carries 35–40% of the exam, so about 24 of a suggested 60 study hours belong to plug-ins, platform APIs, Azure Functions, and flows. The plan below spreads those hours over six weeks.
If you have built Dataverse plug-ins or PCF controls before, AB-400 will feel familiar for about two thirds of the outline. The remainder is where the new exam departs from its predecessor: code apps, Microsoft Foundry agents, and Model Context Protocol (MCP) servers now appear in the skills-measured list. This guide treats those as the weeks where you need documentation open, not memory.
Full disclosure: MSCertQuiz's business is AB-400 practice exams, and the team that writes those questions wrote this page too.
What does Microsoft say about the AB-400 exam itself?
Microsoft's official AB-400 exam page (checked October 15, 2026) describes a candidate who designs, develops, tests, and troubleshoots solution components using Power Platform extension points and generative AI. The table collects what the page states and what it leaves out.
| Item | What Microsoft's page says |
|---|---|
| Credential | Microsoft Certified: Power Platform Developer Associate |
| Availability | Registration opens exclusively for AB-400 on October 16, 2026 |
| PL-400 overlap | PL-400 registration closes October 16; existing registrants can test through October 30, 2026 |
| Language | English |
| Price | Based on the country or region of the proctored exam; no flat figure listed |
| Question count, duration | Not stated on the page |
| Retirement date | None |
Since the page is silent on length, plan for a full-length proctored session and practice with timed sets instead of guessing at a number.
How should you split 60 study hours across the four domains?
Split study time in proportion to the midpoint of each domain's published weight. On a 60-hour budget that gives roughly 11 hours to Build Microsoft Power Platform solutions, 17 to Extend the user experience, 24 to Extend Microsoft Power Platform, and 8 to Develop integrations.
| Domain | Weight | Midpoint | Hours of 60 |
|---|---|---|---|
| Build Microsoft Power Platform solutions | 15–20% | 17.5% | 11 |
| Extend the user experience | 25–30% | 27.5% | 17 |
| Extend Microsoft Power Platform | 35–40% | 37.5% | 24 |
| Develop integrations | 10–15% | 12.5% | 8 |
Midpoints sum to 95%, so the hours are normalized to a 60-hour total and rounded. Move hours toward whichever domain you score lowest on in your first practice set.
What do you study in each of the six weeks?
The order below puts architecture first, because every later domain asks you to choose between mechanisms, and keeps the integration domain for last, because it reuses plug-in and API knowledge from weeks four and five.
Week 1 (11 hours): Architecture and lifecycle
Work through the Domain 1 bullets on where business logic should live (client-side processing, business rules, plug-ins, cloud flows) and when requirements can be met out of the box. Then cover security features that shape a design: managed environments, data policies, security roles, teams, business units, and row sharing. Finish with solution layers, environment variables, Power Platform Pipelines, and Build Tools. Checkpoint: you can say which environment setup supports a four-stage governed pipeline and why a personal pipeline cannot.
Week 2 (9 hours): Client scripting and PCF
Learn the Client API object model, event handler registration, and the Dataverse Web API from scripts. Then cover PCF: the lifecycle events, the manifest, component interfaces, and packaging with the Power Platform CLI. Run a real component through pac pcf push at least once. Checkpoint: you can name the four lifecycle methods and say what a push without a solution name creates.
Week 3 (8 hours): Code apps
Code apps are the newest part of Domain 2. Cover connections, Dataverse tables, flows, Copilot Studio agents, and environment variables from a code app, then deployment concerns: Content Security Policy settings, Application Insights, sharing, Monitor, and performance. Checkpoint: you can explain when data loss policy is enforced for a code app and where you would look when one fails to load.
Week 4 (12 hours): Plug-ins and custom APIs
This is the single heaviest week. Study the event execution pipeline stages, the execution context, images, the Organization service, and registration with the Plug-in Registration Tool. Add custom API messages, business events, and managed identity for plug-ins. Read the Dataverse event framework article closely. Checkpoint: given a requirement, you can pick the stage, the execution mode, and the way to cancel.
Week 5 (12 hours): Platform APIs, Azure, flows, and agents
Cover the Web API and Organization service, retry policies for API limits, OAuth, background operations, and the .NET and Python SDKs. Then Azure Functions for long-running and scheduled work, flow expressions and error handling, child flows, and the Foundry agent bullets that involve MCP servers, Copilot Studio agents, and Work IQ. Checkpoint: you can explain why a 20-minute HTTP call needs a polling design and what a 429 response asks the client to do.
Week 6 (8 hours): Integrations and full-length rehearsal
Cover publishing and consuming Dataverse events, endpoint registration, change tracking, alternate keys, upsert, and custom connectors. Spend the remaining time on timed mixed sets from all four domains and rework every miss against the skills-measured bullet it belongs to. The free AB-400 practice questions are a good first diagnostic.
Which preview-era topics deserve a second look before test day?
Several skills-measured bullets point at features whose documentation is still changing: Microsoft Foundry agents that call Power Platform MCP servers, connecting custom agents to Copilot Studio agents, Work IQ for Dataverse data, policy templates for custom connectors, background operations, and code apps. Study the concepts now, then reread the live Microsoft Learn pages in the week before you sit the exam.
Where this guide and a current Microsoft Learn page disagree, trust Microsoft Learn. Our objectives snapshot is dated October 15, 2026.
Where do candidates lose points on AB-400?
Of the 500 questions in our AB-400 bank, 288 are rated Hard, and the hardest ones turn on a single detail that a quick read skips. These are the details that recur in the bank, with the mechanism each one tests.
| The trap | What actually happens |
|---|---|
| Reading shared variables in a later stage | For Create and Update, a PreOperation or PostOperation plug-in reaches values set in PreValidation through ParentContext.SharedVariables |
| Fixed-delay retries against throttling | A 429 response needs a wait for the Retry-After period; parallelism should follow the x-ms-dop-hint header |
| Longer timeouts for long calls | An HTTP-triggered Azure Function cannot respond past 230 seconds; Durable Functions returns 202 Accepted and the caller polls |
| Trigger conditions written as plain expressions | Each condition must start with @, and several conditions combine with AND |
| Alternate keys with slashes in the data | Characters such as / and + break retrieve and upsert through the Web API even though uniqueness still holds |
| Assuming pac pcf push builds a release | Without a solution name it uses a temporary unmanaged PowerAppsTools solution |
Practice these as pairs: for each, know both the correct mechanism and the plausible alternative the exam will offer instead.
What should you do in the last two days?
Stop learning new features. Reread the reference tables in the AB-400 cheat sheet, take one timed mixed set, and review only the misses. Then open the Microsoft Learn pages for the preview-era topics once more, because those are the pages most likely to have changed since you first read them.
Put week four to the test with real plug-in scenarios
The AB-400 bank holds 500 questions across all four domains, including 40 free ones, so you can check your plug-in and API reasoning before you pay for anything.
See the AB-400 question bank →Should you take PL-400 or wait for AB-400?
Only candidates who registered for PL-400 on or before October 16, 2026 can still sit it, and only through October 30. Everyone else takes AB-400. If you are already partway through PL-400 preparation, the plug-in, PCF, and integration material carries over, and our PL-400 study guide still covers that shared foundation.
What you add for AB-400 is the new material: code apps, agents built in Microsoft Foundry, MCP servers, and Python alongside .NET. The AB-400 cheat sheet keeps the stable reference facts in one place while you work through those.
AB-400 study questions people ask
What is the AB-400 exam?
AB-400 is the Microsoft exam titled Power Platform Developer Associate. It validates that you can design, develop, and implement AI-powered business solutions with Microsoft Power Platform, using generative AI, custom code, automation, integrations, and modern developer tools. Passing it earns Microsoft Certified: Power Platform Developer Associate.
Is AB-400 replacing PL-400?
Yes. Microsoft states that registration for PL-400 closes on October 16, 2026, when registration opens exclusively for AB-400. Candidates who registered for PL-400 on or before October 16 can schedule and take it through October 30, 2026.
How many questions are on AB-400 and how long is it?
The AB-400 exam page does not state a question count or duration. Check your exam booking confirmation for the final numbers, and do not rely on third-party figures for a new exam.
How much does AB-400 cost?
The exam page says the price depends on the country or region where the exam is proctored and does not list a flat price. Look at the price shown when you schedule the exam in your region.
What languages is AB-400 offered in?
As of our October 15, 2026 review, Microsoft lists English only. The page shows no retirement date for the exam.
What coding experience does AB-400 expect?
Microsoft lists development experience with JavaScript, JSON, TypeScript, Power Fx, C#, Python, HTML, YAML, RESTful Web APIs, Azure, Microsoft Foundry, and Copilot Studio. You do not need to be fluent in all of them, but you should read C# plug-in code and TypeScript client code comfortably.
Keep going with AB-400
A timed check across all four domains.
Free AB-400 Practice QuestionsTwelve domain-grouped questions with every wrong choice explained.
AB-400 Certification PageDomains, FAQs, and what the question bank covers.
All Microsoft CertificationsBrowse every certification MSCertQuiz covers.