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INTERNATIONAL SOCIETY OF ARBORICULTURE

EIN 37-1004119 ATLANTA, GA

Revenue 2024
$11,573,930
Expenses 2024
$10,674,901

Program services were 64.9% of total expenses calculated — Part IX's program-services column over total expenses, both as filed.

As filed

Subsection
05
Classification
1000
Street
270 PEACHTREE ST NW STE 1900

These codes are the IRS's own and are shown exactly as filed. What each one means is in the Business Master File documentation (opens in a new tab).

Mission and programs · 2024

Mission

Through research, technology, and education, the International Society of Arboriculture will promote the professional practice of arboriculture and foster a greater worldwide awareness of the benefits of trees.

Activities or mission (Part I)

Through research, technology, and education, the International Society of Arboriculture (ISA) will promote the professional practice of arboriculture and foster a greater worldwide awareness of the benefits of trees.

  • Credentialing - Provide certification examination services for potential candidates and recertification services to existing credentials to support the professional development of the arborists. the credentialing program serves over 61,000 credentials in 45 countries. ISA certification programs managed over 600,000 continuing education units submitted by various credential holders. ISA provides qualification training workshops and credential testing services for participants.

    Expenses $3,608,820 · Revenue $4,911,496

  • Educational Products and Services - EPS manages the development and production of monthly publications for isa members, to disseminate timely and relevant articles, news, information, and research regarding trees and tree care. EGS develops and distributes educational materials for the industry, including publications, workshop curriculum, online learning courses, podcasts, and consumer and industry brochures. 6 issues of the arborist news were published, 6 issues of the arboriculture and urban forestry journal were published, and 3new publications were published: tree injection BMP, Arborists' certification study guide and ITCC rule book.

    Expenses $472,303 · Revenue $1,718,933

  • Events - Operate educational events, including training workshops, conferences, tradeshows, and symposiums, to provide information regarding tree related subjects to members and attendees. ISA held it's Annual Conference and Trade Show in Atlanta in 2024. ISA provides for the International Tree Climbing Championship, North American Tree Climbing Competition, European Tree Climbing Competition, Asia-Pacific Tree Climbing Competition, and Latin America Tree Climbing Competition to highlight and demonstrate the various skills of arboricultural practitioners and tree climbing and creating awareness about the importance of trees and tree care to the public.

    Expenses $1,674,026 · Revenue $1,025,800

  • Expenses $1,176,888 · Grants $61,268 · Revenue $49,107

As filed on the 2024 return.

Officers and directors · 2024

As listed in Part VII of the 2024 return, in the order the filer printed them. Each return names its own; this is not a roster the organization keeps with us.

  • Nicolaas Verloop

    President(Upto Oct 24)

    Total calculated
    $0
    Hours/week
    15

  • Thomas Smiley

    President

    Total calculated
    $0
    Hours/week
    10

  • Gail Nozal

    Vice President(Upto Oct 24)

    Total calculated
    $0
    Hours/week
    5

  • Randall Miller

    Secretary (Upto Oct 24)

    Total calculated
    $0
    Hours/week
    5

  • Sharon Jean-Philippe

    President- Elect

    Total calculated
    $0
    Hours/week
    5

  • Christopher Boza

    Treasurer

    Total calculated
    $0
    Hours/week
    5

  • John Gathright

    Member(Upto Oct 24)

    Total calculated
    $0
    Hours/week
    5

  • Carlos Llanos Rojas

    Member(Upto Oct 24)

    Total calculated
    $0
    Hours/week
    5

  • John Coles

    Member

    Total calculated
    $0
    Hours/week
    5

  • Samuel Ma

    Member

    Total calculated
    $0
    Hours/week
    5

  • Tadashi Touchi

    Member

    Total calculated
    $0
    Hours/week
    5

  • Susan Day

    Member

    Total calculated
    $0
    Hours/week
    5

  • Jason Grabosky

    Member

    Total calculated
    $0
    Hours/week
    5

  • Jessica Sanders

    Vice President

    Total calculated
    $0
    Hours/week
    5

  • Michael Watson

    Member

    Total calculated
    $0
    Hours/week
    5

  • Lori Brockelbank

    Member (Served October-December)

    Total calculated
    $0
    Hours/week
    5

  • Rebecca Johnson

    Member (Served October-December)

    Total calculated
    $0
    Hours/week
    5

  • Tim Walsh

    Member (Served October-December)

    Total calculated
    $0
    Hours/week
    5

  • Stephen Lane

    Member (Served October-December)

    Total calculated
    $0
    Hours/week
    5

  • Lauren Marshall

    Member (Served October-December)

    Total calculated
    $0
    Hours/week
    5

  • Caitlyn Pollihan

    CEO & Executive Director

    Total calculated
    $388,638
    From this org
    $359,703
    From related orgs
    $0
    Other
    $28,935
    Hours/week
    40

    Schedule J breakdown matched by us

    Base
    $357,103
    Bonus
    $2,600
    Other
    $0
    Deferred
    $18,978
    Nontaxable benefits
    $9,957
    Filer's total
    $388,638

  • Freddie Harroway

    Director of Finance

    Total calculated
    $146,025
    From this org
    $132,600
    From related orgs
    $0
    Other
    $13,425
    Hours/week
    40

  • Chastity Austin

    Director of Human Resources

    Total calculated
    $147,985
    From this org
    $131,748
    From related orgs
    $0
    Other
    $16,237
    Hours/week
    40

  • Luana Vargas

    Director of Credentialing

    Total calculated
    $145,000
    From this org
    $126,776
    From related orgs
    $0
    Other
    $18,224
    Hours/week
    40

  • Alice Bagley

    Director of Marketing

    Total calculated
    $135,231
    From this org
    $118,310
    From related orgs
    $0
    Other
    $16,921
    Hours/week
    40

The first 25 listed. Compensation is as filed in Part VII: reportable pay from this organization and from related organizations, other compensation, and hours per week. The total, marked calculated, is our sum of the three dollar columns, with a blank column counted as $0; the form itself has no total. On a Form 990-EZ the columns are Part IV's instead, and on a Form 990-PF Part VIII's — compensation, contributions to benefit plans, and expense account — and the total sums those. A Schedule J breakdown is as filed: base pay, bonus, other, deferred compensation and nontaxable benefits from this organization, with any from related organizations beside each, and the filer's own total. It is shown with the Part VII listing of the same name on the same return. The form gives no key between the two, so that pairing is ours, and is marked matched by us. Earlier years are each on their own filing page.

Filings

  • 2024
    Revenue
    $11,573,930
    Expenses
    $10,674,901
    Contributions
    $3,063,393
    Grants paid
    $61,268
  • 2023
    Revenue
    $10,747,280
    Expenses
    $9,882,585
    Contributions
    $3,040,586
    Grants paid
    $60,781
  • 2022
    Revenue
    $10,071,372
    Expenses
    $8,880,457
    Contributions
    $3,013,018
    Grants paid
    $90,978

The four totals the IRS asks for on Part I of the Form 990, as filed. A dash means the figure was not present on the return — not that it was zero.

Other returns filed

  • 2021 · 990

    Revenue
    $10,308,280
    Expenses
    $7,222,912
    Assets (EOY)
    $12,941,286

  • 2019 · 990

    Revenue
    $7,156,880
    Expenses
    $8,066,767
    Assets (EOY)
    $10,397,561

  • 2018 · 990

    Revenue
    $8,987,074
    Expenses
    $10,248,586
    Assets (EOY)
    $11,767,254

  • 2017 · 990

    Revenue
    $7,215,455
    Expenses
    $7,005,194
    Assets (EOY)
    $9,964,183

  • 2016 · 990

    Revenue
    $6,996,011
    Expenses
    $6,865,291
    Assets (EOY)
    $9,881,510

  • 2015 · 990

    Revenue
    $6,691,349
    Expenses
    $6,486,657
    Assets (EOY)
    $9,577,440

  • 2014 · 990

    Revenue
    $6,747,615
    Expenses
    $6,405,436
    Assets (EOY)
    $9,468,265

  • 2013 · 990

    Revenue
    $6,617,226
    Expenses
    $6,268,553
    Assets (EOY)
    $9,252,951

  • 2012 · 990

    Revenue
    not reported
    Expenses
    $5,564,193
    Assets (EOY)
    $8,582,675

  • 2011 · 990

    Revenue
    not reported
    Expenses
    $5,296,303
    Assets (EOY)
    $8,149,865

Nonprofiteer parses Forms 990, 990-EZ and 990-PF, in a window of recent tax years. These returns are recorded from the IRS e-file index, so their figures were extracted by that index rather than read from the return here — treat them as a different source from the filings above, not as more of the same record. A dash means the index carries no figure; Form 990-T listings carry none at all. Showing the 10 most recent; the API carries the rest.

Grants made

Where these grants went next →

Grants received

No itemized grant names this organization as a recipient. Only grants over $5,000 are itemized, and only by filers of the full Form 990.

Other IRS files

Auto-Revocation List

Not listed. The IRS publishes this list for organizations whose exemption was automatically revoked for failing to file for three consecutive years.

Publication 78

Not present in the most recent drop.

These are two separate IRS files on two separate schedules, shown as published and not reconciled with each other. Neither is a statement about whether a contribution is deductible today: 19,245 organizations appear in Publication 78 while the IRS's own revocation file lists them as currently revoked, more than half of those revoked before 2019. Absence from Publication 78 is evidence of nothing, and presence is not evidence either. Verify current status with the IRS before relying on it.

What this page reflects

The registration facts above come from the IRS Business Master File published 13 October 2026 and read 29 October 2026, for every organization at once. Returns through tax year 2024, the newest we have parsed for this organization.