When Microsoft deemed that vendor support was broad enough, they declared the release SAC.

SAC-T indicated an early-stage feature release. If you’ve been waiting until Microsoft declares a feature release “ready for business,” be aware that with the upcoming 1903 release Microsoft will no longer use the Semi-Annual Channel Targeted (SAC-T) or Semi-Annual Channel (SAC) designations. You’ll want to review the additional information you can obtain at all the Windows 10 update history pages as noted in this blog. With Windows 10 1809, you can track the blocking issues at KB4464619. Recently, Microsoft has been providing more information about blocking issues that impact the roll out of feature releases. Microsoft should be commended for making necessary adjustments to deferrals and support windows, but it is confusing to keep track of feature update releases, their issues and what third-party programs they don’t support. While I’m a fan of Microsoft’s Windows 10 “Windows as a service” process that eliminates waiting for massive service packs, I don’t want to leave it to Microsoft to deem my systems ready for the update release. Changes that Microsoft is making regarding feature release dates might mean rethinking how you manage update deferrals.

I’m getting ready for it by making sure I have the downloads and deferrals in place so I can install it when I want to install it. In May, Microsoft is expected to release the next Windows 10 feature update, known as 1903.

Windows 10 1903 download