Both patch version (e.g. 1.20.13) and (e.g. 1.20) are supported. When is specified, the latest supported GA patch version is chosen automatically. Updating the cluster with the same once it has been created (e.g. 1.14.x -> 1.14) will not trigger an upgrade, even if a newer patch version is available. When you upgrade a supported AKS cluster, Kubernetes minor versions cannot be skipped. All upgrades must be performed sequentially by major version number. For example, upgrades between 1.14.x -> 1.15.x or 1.15.x -> 1.16.x are allowed, however 1.14.x -> 1.16.x is not allowed. See upgrading an AKS cluster for more details.