Should my employer be paying for on-call time?

The general rule is that if an hourly employee must be on-call outside of work, then they have to be paid pay for those hours. That is if the employee has limitations placed on them to the point that they have virtually no control of such time (i.e. they cannot use it for their own enjoyment or benefit); if so, then that employee should be paid (the more restrictions the more likely it is that it should be paid time).

Specifically, considerations in determining if such time is on-call time are:

• the amount of calls that an employee receives during such time (the higher the volume the more likely it is that they must be paid); 
• do any of the calls require the employee to report to work or give advice or over the phone (if so, it is compensable time);
• how quickly must the employee respond to the call (the more immediate the employee's response the greater the likelihood that they are entitled to pay);
• are there geographic limitations as to where the employee can go while on call (if they must stay within a limited distance from work then such time should be compensated); and
• are there restrictions as to what an employee can/cannot do while on call (if, for example, there is ban on alcohol it is more likely that an employee needs to be paid).

So see how thee factors apply specifically to your situation. If you think that you're getting short-changed, then contact your state's department of labor to file a complaint.