Best regards!

Exempt in your context means that the employees are not subject to these wage and hour laws (usually they receive a weekly or bi-weekly salary instead of being paid by the hour). It means they do not receive overtime pay. See the following text:

Employee Lawsuits: Exempt Employees

Some employees and industries are exempt from overtime requirements.

Wage and hour protections for employees can be a very dry subject. There are many CEOs who could care less about the "salary basis" requirement for exempt status. They just want to group all their "white collar" employees into FLSA exempt categories and not have to worry about overtime pay for these employees. The exempt classifications under the Fair Labor Standards Act are never as inclusive as management thinks they are. You cannot simply label a secretary as an "administrative assistant" and expect to be relieved of any obligation to pay him or her overtime if all the employee does is type the supervisor's letters. (http://www.uslaw.com/library/article/carel7ExemptHires.html?...

This article gives a much longer explanation if you're interested in reading it.

In your context, the translation would be something like "no sujetos a las leyes federales y estatales que regulan las horas extras". You really have to explain it like that.

Hope it helps.

Cindi's explanation is very thorough, but what Dany needs is not a definition, but a translation. I would use "empleado as sueldo fijo" for "exempt employee" and "empleado por hora" for nonexempt. They are correct, commonly used, and short.
Hope this helps

Esta es la definición de lo que es un Exempt employee:
Exemptions: Certain employees whose primary duties are managerial, administrative, or professional in nature are exempt from the FLSA's minimum wage and overtime pay requirements.

Quiere decir exento de la aplicación de la ley de sobretiempo y salario mínimo

Buena suerte...

contrary to the english significance of that title it has nothing to do with "trusted employee"...it refers to those non-union employees that are outside wage and hour laws and are basically at will employees in administrative or supervisory slots. Its the description you find in benefit packages, etc. in companies in Mexico.