I am a full-time hourly employee for a large corporation.
I am required to be on call 24/7 every 3 weeks.
The co. policy states that I must return any phone call within 20 minutes and be able to be onsite within 2 hours of getting called.
This limits what I can do on my days off and after normal work hours for that week as I can not be more than 2 hours from my work location, I can not have a drink, etc....

Should I be compensated for being oncall whether or not I am called?

Should I be compensated for my time spent on the phone even if I do not go onsite?

There are no hard and fast rules on what on-call regs are considered so restrictive that you have to be paid for the on-call time.

For a definite answer, you will need to call the MA Atty Gen. Fair Consumer and Labor line.

My OPINION, which along with a buck twenty five will get you on the Blue Line, is that what you describe is not restrictive enough to require them to pay you for being on call, only for the time you actually get called in.

The above assumes that you are a non-exempt employee. If you are exempt, you do not have to be paid for any of it, period.