The ADA prohibits discrimination in all employment practices, including job application procedures, hiring, firing, advancement, compensation, training, and other terms, conditions, and privileges of employment. It applies to recruitment, advertising, tenure, layoff, leave, fringe benefits, and all other employment-related activities.
For additional information, take a look at the following resources:
FAQ: Who is protected from employment discrimination?
FAQ: What is discrimination based on "relationship or association" under the ADA?