ISA Certified Arborists need to read this!

ISA’s legacy Find an Arborist directory search tool on TreesAreGood.org was permanently retired yesterday, 30 June 2026. Directory information did not migrate to the new tool. Arborists certified or re-certified in recent months have a skeleton profile created by ISA. Everyone else has nothing. Of the 50 arborists nearest me only 5 (1 in 10) are in the new directory.

https://certificates.directory.isa-arbor.com/

Get in there, peeps. Claim your profile and add your contact details.

This sub sees many of the same types of questions, prompting the same answers, again and again. So it begs for a FAQ. Dear reader, you can help.

How to find an arborist? Well, let's not harvest the tree before we plant the seed. So, what kind of arborist do you need? Your question really is How do I find the right kind of arborist for the work I need done?

• Licensed. In most of the world arborists are not licensed. In the US only the states of Connecticut, Maryland, and New Jersey license arborists and arborists working in those states must be licensed. Many states license pesticide applicators and those states may also license anyone who offers advice about pesticides. Some counties and cities license arborists. Your county agricultural extension office can tell you about licensing requirements in your area.
• Credentialed. The International Society of Arboriculture (ISA) bestows credentials based on a combination of years of verified experience, prior education, successful completion of knowledge and performance tests, and continuing education. These credentials are Certified Arborist (CA), Certified Arborist Utility Specialist, Certified Urban Forest Professional, Certified Tree Climber, Certified Tree Worker Aerial Lift Specialist, Board Certified Master Arborist (BCMA), and Tree Risk Assessment Qualification (TRAQ). The Tree Care Industry Association (TCIA) lists Accredited Companies and Accredited Utility Contractors (but many members have no accreditation). The American Society of Consulting Arborists (ASCA) recognizes Registered Consulting Arborists (RCA); to even join ASCA requires 5 years of verified experience.
• Contractor. This word has multiple meanings. A state licensed contractor is an elevated class of business person, someone authorized to select and supply the materials to be used on your property, buy the materials at a wholesale rate, and charge you cost plus overhead on the materials in addition to their labor. Every state licensed contractor has a number that can be verified. Get the number and verify it. A contractor is anyone who does paid work and is not an employee. Therefore, the claim "licensed contractor" may indicate mere possession of a city or county business license. If there should be a business license, get that number and verify it too.
• Bonded. Bonding is common among licensed contractors but not arborists. Bonds are a kind of insurance policy in the past was far more valuable than today. How they work is a service provider purchases a bond guaranteeing that if the provider causes damage the bondsman will pay the claim up to a certain limit. Today, business insurance is more important.
• Insured. What kind of insurance, and how much, should an arborist have? That depends on the work the arborist does. Tree climbers and other aerial tree workers, or their employers, should have workers' compensation insurance (WCI). This is very important: in the event of an on-the-job injury or death WCI stands between the tree owner and the state. Tree worker is the single most dangerous occupation in the United States and each state employs expensive attorneys who specialize in recovering costs of injuries from those with legal liability. All arborists and arboricultural business should have general liability insurance, possibly also owned or leased business vehicle and business equipment insurance. Consulting arborists should have professional liability insurance also known as errors and omissions insurance. Clients should require a certificate of insurance (COI); in the US a COI comes on a standard form, the ACORD 25. The COI should list as an additional insured your name and the address where the work is to be done, the estimated date when the work is to be performed, and a brief but specific description of the work: not "services" or even "tree work" but "drop one (1) standing dead oak, 3 ft diameter, in front of house; remove all debris; repair damage to lawn." Better is a written estimate or contract, and the COI refers to that specific document.

Questions? Comments? What is missing?