Microsoft.Data.SqlClient library follows the latest .NET Core support policy for all releases.
View the .NET Core Support Policy
View SqlClient Support Policy on Microsoft Documentation
New stable (GA) releases will be published every six months on a regular cadence beginning with version 1.2, along with 2 to 3 preview releases in between. Long Term Support (LTS) releases will be chosen by stakeholders and maintainers based on a few qualifications and customer response.
LTS releases are supported for three years after the initial release.
Current releases are supported for three months after a subsequent Current or LTS release.