As of late October 2018, these agencies seem to have made the transition over to P25 either full-time or part-time:
Fulton-El Camino Park Police (using both P25 Fulton-El Camino and P25 Sheriff channels mostly full-time, a few radios still on SmartZone)
Sacramento County Airport System (including Fire Department, Operations; not including Sheriff Contract)
Sacramento (City) Local Government (mixed-use, some on the SmartZone system, some on the P25 system)
Sacramento County Park Rangers (already on P25 for their own channels, but now also using the P25 Sheriff channels almost full-time)
Sacramento County Probation (same as the Rangers, had their own channels already on P25, now using the P25 Sheriff and P25 Sac PD channels almost full-time)
Because of this, SSD 1-4, 6; SPD 1, 3, 4, 6 seem to be simulcasted full-time on P25. Other law enforcement channels and fire channels are simulcasted as P25 radios affiliate with them.
They've added some additional channel capacity to the P25 system, Site 12. Unitrunker shows:
851.3875
851.6000
851.6250
851.6500
851.8250
852.0750
852.3500 (alternate cc)
852.5750
853.1875 (alternate cc)
853.4500 (alternate cc)
853.6125
853.8750 (primary cc)
Additionally, both the Davis TRS and UC Davis TRS are still active, however Sacramento County has taken over as point-of-contact on their FCC licenses since they will be coming over to the system eventually.