I'm not sure about all programs, but from the ones at which I interviewed, only UC Irvine had a night float and it was a GOOD night float- no overnight call after your first year, only 6 24-hour calls the whole first year, 6 weeks of night float. The special bonus is that their medicine inpatient rotations also have a night float in which psych residents don't particpate--so you are done at 7pm the days you are on call for medicine.