Essential vs. Marginal Function

Overview
Under the Americans with Disabilities Act (ADA), a qualified applicant or employee is a person who can perform the essential functions of the position, with or without reasonable accommodation. Essential functions are the fundamental duties of a job; they do not include marginal functions. Correctly distinguishing essential from marginal functions is critical when hiring, evaluating accommodation requests, managing medical restrictions, and making employment decisions.

Identifying essential functions
A function may be essential because:

• The reason the position exists is to perform that function.
• A limited number of employees are available to perform the function or among whom the function can be distributed.
• The function is highly specialized, and the employee is hired because of particular expertise or ability to perform it.

When evaluating each job duty, consider the following:

• Does the position exist to perform this function?
• Would removing the function fundamentally change the position?
• Is the function highly specialized or dependent on particular training, licensing, certification, knowledge, skill, or ability?
• How many other employees are available and qualified to perform the function?
• How much time does the employee actually spend performing the function?
• What are the consequences if the employee in this position does not perform the function?
• What do current employees in the position actually do?
• What did past employees in the position do?
• Do a collective-bargaining agreement, civil-service rule, ordinance, operating procedure, or other governing document identify the duty?
• Does the city’s current written job description identify the function as essential?
• Can the function be performed another way, at another time, with equipment, through a work-process modification, or with another reasonable accommodation?

The last question is particularly important. The ADA does not require a city to eliminate an essential function, but it may require the city to modify how, when, or where the employee performs the function if doing so is a reasonable accommodation and does not create undue hardship.

Practical guidance
Maintain clear, current job descriptions that identify essential functions separately from marginal duties. Describe work requirements in functional, objective terms—for example, “operates a dump truck,” “responds to emergency calls,” “lifts and carries equipment weighing up to 50 pounds,” “conducts on-site inspections,” or “prepares and presents monthly financial reports”—rather than relying on general labels such as “must be physically fit” or “must have regular attendance.”

A written job description prepared before advertising or interviewing applicants is evidence of essential functions under the ADA. It is not conclusive, however. Courts and the EEOC also consider the city’s actual operating practices, the consequences of not performing the duty, the experience of current and former incumbents, and other relevant evidence. A description that conflicts with the position’s actual day-to-day work may carry limited weight.

Review job descriptions periodically and whenever there is a material change in staffing, technology, work location, organizational structure, equipment, service delivery, supervision, or job duties. Preserve dated versions so the city can identify the job description that was in effect when a hiring decision, accommodation request, or other employment action occurred.

• Municipal HR cautions
  Do not label every duty “essential.” Overinclusive job descriptions can undermine credibility and make accommodation analysis more difficult.
• Do not assume that a duty is essential simply because it is performed frequently. A duty performed infrequently may still be essential if failure to perform it would have serious consequences, such as emergency response, safety, statutory compliance, or continuity of critical utility operations.
• Do not assume that a low-frequency duty is marginal. A police officer’s emergency response, a utility operator’s response to a system failure, or a finance officer’s legally required reporting duty may be essential even if it occurs only periodically.
• Do not automatically deny an accommodation because it affects an essential function. First determine whether the employee can perform that function through a modification in method, equipment, schedule, location, assistance, or another reasonable accommodation.
• Do not permanently reassign essential functions to coworkers as an accommodation. Temporary adjustments may be appropriate under a different law or circumstance, including the PWFA, but the ADA generally does not require elimination of an essential function.