Earlier this year the NBME released updated 2020 practice materials for both Step 1 and Step 2 CK. There are a bunch of new Step 1 questions and the Step 2 set is entirely brand new (the first meaningful change in several years). I was going to continue my annual tradition of explanations but then noticed that the website reverted back to the 2019 sets.
As is their tendency, the NBME isn’t very quick to manage outdated URLs. The PDFs for both new sets are still accessible:
I don’t know if these will simply come back as official sets soon, but it seems they were likely removed because of COVID-19, so it might be a while.
But they are free highest-quality questions and remain worth your time.