A marginal function is a job-related task that is not an essential aspect of the job. Because this task is non-essential, it could be removed from an employee’s job responsibilities if the employee were unable to perform the task due to a disability. In fact, removing a marginal function could be a reasonable accommodation. For example, consider a person who works as a housekeeper at a hotel. This person can walk well but cannot walk up and down stairs. If a small part of the job is to clean the stairwell, the hotel could reassign that responsibility to another housekeeping staff member as a reasonable accommodation.
Marginal functions are different from essential functions—essential functions are tasks that are core aspects of a job.