Do I have to be on the latest Exchange Cumulative Update to be supported?

I can’t tell you how many times I have admonished posters in the forums about not being on the latest Cumulative Update (CU) for Exchange 2013. After all, it has all the latest fixes and you want to be supported right?

It’s generally good advice, but is one really not supported if not on the latest and greatest? Yes and No.

When the original 2013 Servicing Model was announced back in, well, 2013, the support requirements were pretty clear:

Q: How long is a CU supported?

A: A CU will be supported for a period of three (3) months after the release date of the next CU. For example, if CU1 is released on 3/1 and CU2 is released on 6/1, CU1 support will end on 9/1.

This was met with some resistance as many on-premises orgs worried about the cadence schedule and their ability to keep up and still allow for proper testing, roll-out etc… Paul lays this out much better than I could here.

As Paul mentions in his post, Microsoft will not simply turn you away if are running an older CU, though they may suggest you upgrade.

But where is that actually officially stated for all the world to see?  It was some time ago beginning with the release of CU2 in July of 2013 and linked in TechNet:

In the new Exchange servicing model customers will continue to receive assistance from Microsoft Support for the lifecycle of the Exchange server product – a customer is not required to be at the most current CU to receive assistance. There are two scenarios that we would like to clarify though:

  1. If during the course of a support incident it is determined that the solution is available in a published CU (e.g., CU2), the customer will be required to install the update that contains the fix. We will not be building a new fix to run on top of a CU published earlier (e.g., CU1).
  2. If during the course of a support incident it is determined that you have discovered a new problem for which we confirm a fix is required, that fix will be published in a future CU that you can then install to correct the problem reported.

Note an important exception:

You will see this blurb on every CU release:

“Reminder: Customers in hybrid deployments where Exchange is deployed on-premises and in the cloud, or who are using Exchange Online Archiving (EOA) with their on-premises Exchange deployment are required to deploy the most current (e.g., 2013 CU15, 2016 CU4) or the prior (e.g., 2013 CU14, 2016 CU3) Cumulative Update release.”


Maybe you already knew this. But it’s a reminder to myself to always qualify my answer when I tell a forum poster they need to be on the latest CU “to be supported”!




Recommended Reading