It seems a lot of programs only have call the first 2 years. After that, it either disappears or drops to maybe once every 3-weeks or so.
MUSC has no call outside of your medicine months. You just go through two months of night float, if I recall directly. Much nicer than being on-call, I'd think. Regular hours are nice, though it could be a little tough with a working and unsympathetic spouse.
This just really varies by program. Be aware that some programs will tell you that you're only on-call until X-time, but X-time usually translates into several hours of work beyond X. Vanderbilt comes to mind on that one... Good program, but it's good to know what you're getting into.