What is Moonlighting?
Moonlighting refers to the process by which one physician covers for another physician and get paid for that.
In other words you do your friend's duty and you get his/her hourly payments.
It's called moonlighting because it's usually done at night shifts.
Moonlighting is not available in all programs and even some states ban it.
J1 visa residents are not allowed to moonlight while H1B visa holders they can (though am not sure about this).
At all times, any resident should not do more than 80 hours per week as it has become a federal rule and is applied by all hospitals.
Some states require that you are a fully licensed physician before you can make it (which mean that you should have passed USMLE step 3).
There two types of moonlighting
In house: you cover your colleagues in the same facility
External: you cover other physicians in other hospitals
It's not overtime, you will be paid exactly what the physician you are covering supposed to be paid.
Many residents they do it just by agreement with the other physician without the knowledge of the authorities (such as program director or chief resident).
In certain hospitals moonlighting is not covered by malpractice insurance so it's really risky but still people do it, you know $$$