In time the Ultra HD Premium logo should become ubiquitous ... but the technology is slowly appearing to make 4K possible: some Netflix shows are now available in 4K, for instance.
If you can't get Netflix to stream in 4K or Ultra HD despite being on the Premium ($15.99/month) plan, first ensure that the title is available in 4K. While Netflix doesn't disclose this on title ...
Just log in to your Netflix premium account ... You can also check to see if individual titles have the "4K Ultra HD" icon underneath the series logo and to the right of the release date and ...