Deploying Azure SQL Database managed instances to non-delegated subnets will be retired on 1st May 2020. After that date, you will be able to deploy managed instances only to subnets delegated to the Microsoft.SqlmanagedInstance resource provider.
Learn how to enable subnet delegation on managed instance subnets.
Deploying managed instances to an empty subnet
If you are deploying managed instances through the Azure portal, everything is already set for you.
If you are deploying managed instances using PowerShell, check this sample for help tailoring your scripts.
If you prefer using ARM templates, read this article for guidance.
Deploying managed instances to a subnet already containing them
To delegate a subnet already containing a managed instance to the Microsoft.SqlmanagedInstance resource provider, follow these instructions.
On 1st July 2020, all remaining subnets containing managed instances will be automatically delegated to the managed instance resource provider.
