The previews of EF Core 5.0 require .NET Standard 2.1. This means:

• EF Core 5.0 runs on .NET Core 3.1; it does not require .NET 5.
  • This may change in future previews depending on how the plan for .NET 5 evolves.
• EF Core 5.0 runs on other platforms that support .NET Standard 2.1.
• EF Core 5.0 will not run on .NET Standard 2.0 platforms, including .NET Framework.