Most government agencies, from federal to municipal, comply with the ANSI Tree Care Standards. In addition, these standards are endorsed by nearly all professional organizations involved with trees, forestry, landscaping, and grounds maintenance.

ANSI stands for the "American National Standards Institute". ANSI is a private, non-profit organization that is involved in the creation of standards for hundreds of industries. Standards are specific principles or criteria, established by authority or convention. However, ANSI does not itself write these standards. What it contributes, instead, is a process.

ANSI was founded on the idea that private industry is in the best position to understand itself and will do the best job, both for itself and for the general public, in coming up with standards to guide that industry. In other words, ANSI Standards are not governmental regulations imposed from the outside, but rather are drawn up within the industry, by that industry, to meet needs identified by that industry. Government may then use these documents as a basis for licensing, regulation or enforcement, but that happens only after the standards are drawn up.

ANSI facilitates development (of standards) by establishing consensus among qualified groups. The process depends upon three things—a fair system, the selection of the right groups to participate, and consensus among these groups.

The Tree Care Industry Association (TCIA), formerly known as the National Arborist Association (NAA), is the ANSI secretariat of the "A300 Tree Care Standards" for trees, shrubs, and woody plants. The TCIA (NAA) is responsible for providing administrative support, appointing a secretary, and seeing that the A300 committee meets ANSI's procedural requirements. ANSI requires standards be re-affirmed, revised or removed every five years. The committee is composed of industry associations, governmental agencies, university researchers, and private tree care companies with a national presence. The representatives come from a very diverse group, provide broad input, and consider all public comments when drafting new or revised standards. Only a two-thirds majority is needed to pass a revised standard when voting. However, in all but one instance, the vote has been unanimous before each standard is adopted.

What good are these standards?
   • To begin with, they provide a uniform vocabulary for tree care.
   • The standards also clarify the job to be done, protecting both parties.
   • Using them will promote good arboricultural practices. Tree care terms and techniques are defined carefully, and their appropriate use is explained.
   • Tree care professionals follow the standards to demonstrate that they follow a specific and carefully considered program of tree management that is considered the norm for the industry.
   • "Best Management Practices" booklets have been published by the ISA and other organizations as aids in the interpretation and implementation of the ANSI A300 guidelines.
   • Judges use ANSI A300 standards to help decide court cases.