Microsoft has just announced its latest DirectX 12 feature level 12_2 specification, adding a bunch of new API-level features to DirectX 12 feature level 12_1.
This is separate to DirectX 12 Ultimate, with Microsoft explaining DirectX 12 Ultimate was stamped on its own and its logo requirement is important enough that it gets bundled into a new feature level. DirectX 12 Ultimate isn't feature level 12_1, rather DirectX 12 Ultimate means you have DirectX Raytracing, Mesh Shaders, Sampler Feedback, and Variable Rate Shading.
All of these features together, and a few new features, make up DirectX 12 feature level 12_2 which will include DXR 1.1, Shader Model 6.5, Variable Rate Shading tier-2, Resource Binding tier-3, Tiled Resources tier-3, Conservative Rasterization tier-3, Root Signature tier-1.1, WriteBufferImmediateSupportFlags, GPU Virtual Address Bits resource expansion, among several other Direct3D raster rendering features.
You will need a WDDM 2.0 driver and compatible GPU to make use of feature level 12_2, which includes the current-gen AMD and NVIDIA hardware -- and even "AMD's upcoming RDNA 2 architecture based GPUs will include full feature level 12_2 support".
Feature level 12_2 works on "NVIDIA GeForce RTX and NVIDIA Quadro RTX GPUs" explains Microsoft, but doesn't specifically say if the new Ampere-based GeForce RTX 30 series graphics cards will work -- but they will, we all know that.