There's two classes of employees in US labor law, exempt and non-exempt. It's called exempt/non-exempt because a class of employees is exempt from the Fair Labor Standards Act which defines rules for overtime.
To be exempt you have to be paid on a salary basis, you have to make over a certain wage (which, until a few months ago, was a comically low $23,600/yr), and have certain job duties.
These job duties that are required are defined in the FLSA. There's executive employees, administrative employees, professional employees, computer employees, and outside sales employees. The text is here: http://www.ecfr.gov/cgi-bin/text-idx?tpl=/ecfrbrowse/Title29...
In general, most salaried employees do not regularly work unpaid overtime in the US. For example, the one time I ever worked overtime in my software engineering career it was paid overtime (paid at my normal salary). I had a friend who was an (I think?) accountant and she had to work on her vacation otherwise she'd fall behind. Some workplaces are abusive and the law allows it for some classes of employees but it's not the norm outside of the bay area software industry.
To be exempt you have to be paid on a salary basis, you have to make over a certain wage (which, until a few months ago, was a comically low $23,600/yr), and have certain job duties.
These job duties that are required are defined in the FLSA. There's executive employees, administrative employees, professional employees, computer employees, and outside sales employees. The text is here: http://www.ecfr.gov/cgi-bin/text-idx?tpl=/ecfrbrowse/Title29...
In general, most salaried employees do not regularly work unpaid overtime in the US. For example, the one time I ever worked overtime in my software engineering career it was paid overtime (paid at my normal salary). I had a friend who was an (I think?) accountant and she had to work on her vacation otherwise she'd fall behind. Some workplaces are abusive and the law allows it for some classes of employees but it's not the norm outside of the bay area software industry.