Yes, they can do this--they can require you to work more, even three times as much, for the same pay, so long as you are earning at least minimum wage (i.e. that if you divide your pay by the number of hours worked per week, the hourly rate is at least minimum wage). Employers have full discretion over pay and hours worked, subject to the wage and hour laws: i.e. minimum wage and overtime. Note: if you are not exempt from overtime--you can find the tests for when an employee is exempt on the U.S. Department of Labor website--then if you work more than 40 hours in week, you must be paid overtime for all hours past 40. And note further that just because someone is paid a salary does not mean they may not get overtime: to be exempt, you must be paid a salary *and* meet one or more of the tests for exemption; salaried staff can receive extra pay for working more than 40 hours in a week.If you don't work the hours they want you to, you can be terminated. But if you do work them and are paid less than minimum, or should receive overtime (see above) but do not, you could file a wage-and-hour complaint with the department of labor.