If the DBMS version you are using is no longer supported by the developer, you will still have access to your data. However, in this case, the creation of new cluster nodes will not be available and other features may be restricted. You will be notified by e-mail and in your personal cabinet about automatic upgrade to the nearest supported version, about the dates of work and database availability. Such upgrade will be performed even if the client has disabled automatic upgrade.
The client is notified about minor version update at least 7 days in advance, about major version update at least 1 month in advance. Upon receipt of such notification, the customer should check the software interfacing with MongoDB for compatibility with the new version. If necessary, the customer should take steps to ensure compatibility with the new version.