We are using this issue to cover specifically end-to-end support for hierarchyid. SQL Server UDTs are covered by #12796, and spatial is covered by #1100.

As noted in #365 (comment), we already support mapping a property of this type where the type is available.

Here is what is still missing before we can say we support hierarchyid:

• Currently the type is only available in .NET Framework (mostly because Microsoft.SqlServer.Types hasn't been ported)
• Presumably we should support usage of members of the type, functions, etc. in queries

Original issue

sql server special data types add in EF5 and later but hierarchyid and user defined types not implemented yet.please work on hierarchyid and user defined types that use in real website and enterprise.

Note by @rowanmiller: Also relevant - [C# Feature Request] Hierarchy Data Type #16193