For UCs and CSUs, high school stuff is not required for junior-level transfers (i.e. those who will have 60 credit units by the time they transfer, often meaning that they have completed about 30 with another 30 in progress in the academic year that they apply).
For lower division transfers with fewer credit units, UCs and CSUs do require high school stuff, but no UCs are currently accepting lower division transfers, and only a few CSUs are.