Definition of Essential and Marginal Functions:

"Essential Functions" as defined by the ADA:

1. The fundamental job duties of the employment position the individual with a disability holds or desires. The term "essential functions" does not include marginal functions of the position.

2. A job function may be considered essential for any of several reasons, including but not limited to the following:

   (i) The reason the position exists is to perform the function;
   (ii) Limited number of employees are available among whom the performance of that job function can be distributed; and/or
   (iii) The function may be highly specialized so that the person is hired for their expertise or ability to perform the particular function.

3. Evidence of whether a particular function is essential includes, but is not limited to :

   (i) The employer's judgment;
   (ii) Written job descriptions prepared before advertising or interviewing applicants for the job;
   (iii) The amount of time spent on the job in performing the functions;
   (iv) The consequences of not requiring the incumbent to perform the functions;
   (v) The work experience of past incumbents in the job; and/or
   (vi) The current work experience of incumbents in similar jobs.

"Marginal Functions" is defined as:

• Any task that is considered to be a peripheral, incidental, or minimum part of the job.

• Tasks that can be easily transferred to another employee without hurting the employer's business.

The ADA focuses on job performance and not marginal duties in determining what is an essential job function.

If the function of the job was removed, would the basic purpose of the position be destroyed. Or would it be an inconvenience?

For example:
A federal court held that answering the telephone was not an essential function of a time-and-attendance clerk at the post office. They found that the clerk was responsible for tallying, documenting, and analyzing the hours that postal service employees worked. Therefore, it would be discrimination not to hire an otherwise qualified individual who is deaf or has a speech disability.