.NET 3.5 SP1 support ends Jan 9, 2029. For .NET 4.8 there currently there is no support end date. Don't think it's gonna be sooner than 3.5. > .NET Framework 4

.NET 3.5 SP1 support ends Jan 9, 2029. For .NET 4.8 there currently there is no support end date. Don't think it's gonna be sooner than 3.5. > .NET Framework 4.8 is the latest version of .NET Framework and will continue to be distributed with future releases of Windows. As long as it is installed on a supported version of Windows, .NET Framework 4.8 will continue to also be supported. https://dotnet.microsoft.com/en-us/platform/support/policy/dotnet-framework https://dotnet.microsoft.com/en-us/platform/support/policy/d... I think for new apps, you should choose .NET Core. But for legacy apps, I suppose you can take your time. .NET Core actually has much shorter LTS lifecycle. Only 3 years: https://dotnet.microsoft.com/en-us/platform/support/policy/dotnet-core https://dotnet.microsoft.com/en-us/platform/support/policy/d... In our case, a fairly big monolith .NET 4.8 web app is being migrated to .NET Core by splitting that monolith into microservices that run on .NET Core. Can't say if it is for better or worse, more moving parts in infrastructure for sure.