My t is in private practice going on 20 years and does not have a supervisor. She does have her own therapist that she talks to twice a month she's told me. I didn't actually know she didn't have a supervisor until awhile back when I got all freaked out about how I would find out if she died (since we do only phone sessions now) and she admitted she didn't even have a professional will at that time, and didn't have a supervisor either. It was an "interesting" time in my therapy working through that fear.