Guidelines for Essential vs. Marginal Positions

The Americans With Disabilities Act (ADA) and Essential Job Functions

The Americans With Disabilities Act (ADA) requires employers to base job-related decisions on a person’s ability to perform essential job functions under reasonable accommodations. Job descriptions must specify these essential functions, and employment decisions should be made accordingly. Non-essential functions are considered marginal and should not be used as a basis for employment decisions. Both essential and marginal functions must be clearly defined in job descriptions.

Understanding Essential and Marginal Functions

An essential function is a fundamental duty or responsibility that is critical to the job, while a marginal function is relatively less important to the job’s purpose. An essential function cannot or should not be delegated to others, but a marginal function, while desirable to include in the job, can be assigned to another position without significant issues.

A marginal function may be important to the overall work unit, but it is not essential for a specific job. It must still be completed, but it can be handled by another employee or position.

Guidance on Determining Essential or Marginal Functions

An article by P.C. Grant in Business Horizons (March-April 1997), titled “Essential or marginal? Job functions and the Americans with Disabilities Act,” provides valuable insights into this matter.

  • Three factors to consider when evaluating a function as essential or marginal:
    1. Relationship of the functions to other tasks within the job
    2. How reassigning the functions will affect other employees and their jobs
    3. Significance of the function and the conditions under which it is performed

Practical Example

Let’s consider a job that involves operating a machine. The job description mentions “painting the machine twice a month.” However, this task is not critical to the job’s execution. “Operating the machine” is the essential function, so it is listed as such. “Painting the machine” is a marginal function because it’s not vital to job performance. Reassigning the “painting the machine” task would not impact the job description for “Machine Operators.”