I don't think payment for on call is the norm in the USA - it can be very lucrative in the uk I knew of people on 4 in 4 who got called twice a year. 15 Years

I don't think payment for on call is the norm in the USA - it can be very lucrative in the uk I knew of people on 4 in 4 who got called twice a year. 15 Years ago it was £400 for 1 in 4 plus Toil (time off) for time worked