I don't think there is going to be a "standard". It's going to depend on the size of the group, the number of hospitals covered, the type of practice (if you manage BMT and leukemia patients for instance), the culture of the hospitals, etc. But I can give you examples of community practice that I'm familiar with.
My old group (hospital employed community) had ~14 docs covering 5 hospitals. No acute leuks or transplant, minimal inpatient chemo, almost all patients with hospitalists as primary. Call was evenly split among the group which meant ~2 weeknights a month and ~4 weekends (Fri 5p - Mo 7a) a year. Calls were obviously variable but a busy night was half a dozen calls (mostly bunched in the 5-7p and 5-7a times) and a busy weekend would have you seeing 10-12 patients (total, not daily) over the course of the weekend. We had an NP to take outpatient calls during the day. I had plenty of weeknights and even a couple of weekends that were complete no-hitters over the course of 11 years at that job. I can count on one finger the number of times I ever went back to the hospital after hours to manage a patient, and that was at 7pm on a Thursday, not 3am on a Sunday or anything ridiculous.
Another group I know well (large physician owned MSG) covers 2 hospitals with 4 (now 5, soon to be 6) docs. Call is again evenly split but they choose to do a full week at a time and cut back their clinical time by 20% during their call weeks. They too would field a few calls a night and see 5 or 6 patients a weekend. They have a triage RN on weekends who fields outpatient calls and only calls them for critical things, the rest goes in the EMR.
A group I'm somewhat familiar with (true PP) has ~20 docs, again covering 7 or 8 hospitals but divided into 2 groups for the purposes of taking call. Similar volumes to the others except this group does manage acute leuks and auto BMT so gets more inpatient calls. Call frequency is like my old group (weeknights and weekends are separate and are "Q-Doc". They pay a nurse to take outpatient calls 24/7 and only take direct hospital calls and urgent patient stuff from the triage RN.
My current job has 2 docs. We take no call. Zip...zero...nada. Hospital employed rural community-based practice covering one rural CAH. Calls are routed to the local mothership (65 miles away) and the ED and hospitalists basically understand that if they need our help managing something in the middle of the night, the patients need to be shipped out to a higher level of care anyway and they just do it.
