This article lists the OfficeScan versions that can be upgraded to Apex One 2019.
Once the server is upgraded via patch or Apex One, the connected agents will self-update to the same version unless configured otherwise. For reference: Controlling which agents will upgrade in OfficeScan/Apex One.
The patches and critical patches enclosed in dotted lines are optional.
For a complete list of installation and upgrade requirements, refer to the Apex One 2019 product documentation.