Absolutely. For some types of occupations and work, an employer cannot pay you salary to compensate you with one rate for all hours of work. It depends very much on specifically what you do in your job. Sometimes even someone in a “supervisor” position may be entitled to overtime if the “supervising” is a relatively unimportant function of their job, and their primary job duties are ones that would entitled them to overtime. The more routine and manual your job duties, and the less independent discretion and decision-making responsibility you have in your job, the more likely that your job is non-exempt – meaning, not exempt from the requirement that the employer pay you overtime for hours over 40. Talk a lawyer.