The CIT design has evolved recently from a system in which the central solenoid outer boundary interacts with the inner legs of the toroidal field coils for mutual radial support during operation, to a system in which the central solenoid is radially self-supporting. The machine has also undergone some dimensional changes with a resulting increase in the demand for the total flux swing by the poloidal field (PF) coil system from 61 to 75 volt-seconds. This paper summarizes features of the two central solenoid designs and selected requirements for fabrication and operation. It also presents an update on results from the R&D program for this 20+ tesla coil system, together with future plans.