SharePoint Agents Upgrade: What to Do Before March 2027

TL;DR: Microsoft is retiring the .agent file format behind agents in SharePoint and OneDrive. From mid-November 2026, "Create an agent" in SharePoint opens Microsoft Copilot Agent Builder, and new agents land in the Plugin store instead of a site library. Existing .agent file agents keep working until the end of March 2027, then stop working in SharePoint, Teams and the Copilot app during April 2027. Every existing agent needs a decision: rely on Copilot in SharePoint, convert it to a skill, upgrade it to a Microsoft 365 agent, or retire it. Inventory now, pilot the upgrade in November and finish well before the deadline.

On October 16, 2026, Microsoft published Message Center post MC1511052, "Upcoming changes to Agents in SharePoint and OneDrive." It is easy to read as a minor feature update. It is not. Every agent that a site owner built with the SharePoint agent builder over the last two years is stored as a .agent file, and that format has an end date: the end of March 2027, about 23 weeks from today.

The change is good news for most organizations. SharePoint agents move into the same ecosystem as the rest of Copilot, with one catalog, one builder and central governance through the Microsoft 365 admin center and Agent 365. The catch is that nothing is migrated for you. Each agent needs an owner to choose a path, and some placements, such as Teams chats and Agent Link web parts, have to be rebuilt. Organizations that start in November will finish calmly. Organizations that start in March will be explaining to users why their favorite site agent disappeared.

What is changing with agents in SharePoint and OneDrive?

Microsoft is aligning SharePoint and OneDrive agents with the Microsoft Copilot extensibility ecosystem, so that they appear in the Copilot app home experience and the Microsoft plugin registry alongside every other approved agent and plugin. The rollout happens in two waves.

Which upgrade path fits each agent?

Microsoft offers three paths, and the right one depends on what the agent helps people do today. This is the decision that matters most, so make it per agent rather than per site.

There is a fourth path that Microsoft does not list but every inventory reveals: retire it. Agents built for a one-time project, duplicated across sites or unused for months do not need to move. Letting them expire is a perfectly good outcome, as long as it is a decision and not an accident.

If your site owners are unsure whether a skill or an agent fits better, our guide SharePoint Skills Explained: Turn Repeatable Work into Reusable AI Workflows explains how skills work. For agents that may grow beyond Agent Builder, see Agent Builder vs. Copilot Studio: Which One Should You Actually Use in 2026?

Why does the SharePoint agent upgrade matter for IT and business leaders?

SharePoint agents were the easiest agents in Microsoft 365 to create. Anyone with edit rights on a site and a Copilot license could build one in a few clicks, and many did. That ease is exactly why this change deserves leadership attention.

• Most organizations do not know how many they have. .agent files live in site libraries, often under Site Assets, and are created by site owners rather than IT. Agent counts usually surprise people, as we showed in Your Agent Estate Doubled. Your Controls Didn't.
• Governance moves to a central place. After the upgrade, Agent Builder, the Microsoft 365 admin center and Agent 365 become the places where agents are managed, governed and measured. That is a real improvement over files scattered across sites, but only if admins configure it before agents arrive in volume.
• The user experience changes. Agents placed in Teams chats and channels must be added again, and Agent Link web parts stop working in April. People who rely on a site agent every day will notice.
• It sits beside other 2027 deadlines. Microsoft announced the Copilot Studio Teams app retirement on the same day, and Restricted SharePoint Search retires on January 31, 2027. Handle them as one agent and content readiness program, not three separate fire drills.

What this means by sector

• Nonprofit: Program and fundraising teams often built site agents to answer questions about grant guidelines or volunteer handbooks. With small IT teams, prioritize the handful of agents staff use weekly, and retire the rest. Converting a frequently used agent to a skill can be the lightest path when the task is narrow.
• Education: Faculty and departments may have created agents for course sites, admissions or student services. Confirm ownership before staff turnover at the end of term, and keep any agent that touches student information under a named owner and a documented review.
• Government: The rollout covers Government clouds, but Copilot in SharePoint is still listed as coming soon to Government clouds. Agencies should not plan on the "use Copilot in SharePoint" or "convert to a skill" paths until those capabilities are available in their cloud. Plan the Agent Builder upgrade path first, and treat agent configuration changes as part of your records and accountability trail.

What should you do before the March 2027 deadline?

A practical plan takes a few hours a week, not a large program. Here is the sequence we recommend to clients.

1. Count every .agent file agent (now to mid-November). Search your tenant for .agent files, check Site Assets on active sites and use Microsoft's guidance on finding existing agents linked from MC1511052. If you use the Copilot Agent Kit, the Agent Inventory V2 release makes this faster.
2. Give every agent an owner. Record the site, the creator, the current owner and how often it is used. An agent with no owner and no recent use is a retirement candidate by default.
3. Decide the path for each agent. Use the three paths above, plus retirement. Write the decision down so site owners know exactly what is expected of them.
4. Pilot the upgrade in November. As soon as the Upgrade to M365 Agent button and the conversion skill reach your tenant, upgrade two or three agents with willing owners. Check that knowledge sources, permissions, sharing and answer quality match the original.
5. Set governance before upgrades scale. Decide who can share agents, how agents are approved into the Plugin store and who reviews usage in the admin center and Agent 365. If you are unsure what your licenses cover, read Agent Identity Governance Licensing: Why Your E3 and E5 Tenants Cannot Govern Agents.
6. Rebuild the placements people rely on. Add upgraded agents back to Teams chats and channels, and replace Agent Link web parts with the Agent Chat web part once it is available. Tell users where each agent now lives.
7. Set an internal deadline of February 28, 2027. That leaves a month of buffer before .agent files stop being supported. In March, confirm that every remaining .agent file is either upgraded, converted or intentionally retired.

How do you tie the SharePoint agent upgrade to measurable value?

An upgrade is the cheapest moment you will ever get to ask whether an agent earns its place. Today, most SharePoint agents have no baseline, no owner accountable for results and no usage data anyone reviews. After the upgrade, agents sit in one catalog with usage analysis in the admin center and Agent 365. Use the transition to start measuring.

For each agent you keep, track four numbers each month:

• Active users: how many people used the agent, compared with the audience it was built for.
• Questions resolved: how many requests it handled without someone emailing the site owner or opening a ticket.
• Time returned: minutes saved per request, multiplied by volume and a loaded hourly rate.
• Cost to run: the licenses or consumption the agent depends on, plus the owner's time to maintain it.

A simple example shows how quickly the numbers become useful. An HR policy agent that answers 400 questions a month and saves five minutes on each returns about 33 hours a month. At a loaded rate of $60 an hour, that is roughly $2,000 a month in capacity, which is the kind of figure that justifies the owner's time to upgrade it. An agent that answered 12 questions last quarter tells a different story, and retiring it frees attention for the agents that work. For a fuller framework, see Beyond 'Active Users': The Copilot Adoption Metrics That Actually Prove Value.

The organizations that come out ahead will not be the ones that upgraded the most agents. They will be the ones that can show which agents are worth upgrading.

Frequently asked questions about the SharePoint agent upgrade

When do SharePoint .agent file agents stop working?

Microsoft says agents using the .agent file format keep working across SharePoint, Teams and the Copilot app until the end of March 2027. The rollout that turns them off begins in early April 2027 and is expected to complete by mid-April 2027. After that, the Agent Link web part, the immersive experience and the SharePoint chat pane no longer work with .agent file agents.

Do we need to change our agents right now?

No. Existing agents keep working and can still be edited during the transition. What you should do now is count your agents, assign owners and choose a path for each one, so you are ready to upgrade when the tools arrive between mid-November and early December 2026.

Does the built-in site agent need to be upgraded?

The ready-made agent that comes with every SharePoint site does not use a .agent file, so this change targets the custom agents that site owners built and saved as .agent files. Where Copilot in SharePoint is available, it is also the recommended replacement for custom agents that only answer general questions about a site.

Will upgraded agents stay in our Teams chats and channels?

No. Microsoft notes that upgraded agents must be added again to Teams chats and channels. Plan this as part of each upgrade, and tell users where to find the agent afterwards.

How can 2toLead help with your SharePoint agent upgrade?

2toLead helps organizations across nonprofit, education, government, healthcare, financial services and professional services turn agent deadlines into governed, measurable outcomes. In a SharePoint Agent Upgrade Review, our Microsoft MVP team will:

• Find every .agent file agent in your tenant and match it to an owner and usage level
• Recommend a path for each agent: Copilot in SharePoint, a skill, a Microsoft 365 agent or retirement
• Pilot the upgrade with your site owners and rebuild the Teams and page placements people rely on
• Configure sharing, Plugin store approval and Agent 365 governance before upgrades scale
• Set up a simple monthly scorecard that shows which agents earn their place

Explore more practical guidance on the 2toLead Insights hub, or talk to our team about your SharePoint agent upgrade plan.

No hype. Just practical, governed AI that actually gets adopted.