Hourly computer programmers and overtime pay

Q. We employ computer programmers who write sophisticated custom software programs for clients. We bill their services by the hour and pay them by the hour, based on their experience and the work involved. The hourly rates we pay range from $30 to $80 per hour. Sometimes, there is a rush on a project and the programmers have to work overtime. Do we have to pay time and a half the hourly rate if the programmers work over 40 hours per week? ....