International Society of Arboriculture
Credentialing Trends & Analysis
Thirteen-year longitudinal view across all ISA credential tiers, 2012 through 2025
Snapshot
Certifications held (active credential holders as of reporting year-end)
Core & advanced certifications
| Credential | '12 | '13 | '14 | '15 | '16 | '17 | '19 | '21 | '23 | '24 | '25 | Trend | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| ISA Certified Arborist® | 27,728 | 27,917 | 28,404 | 29,772 | 30,562 | 31,400 | 34,707 | 35,944 | 37,692 | 40,048 | 38,825 | |||
| Utility Specialist® | 1,749 | 1,831 | 1,915 | 1,969 | 2,017 | 2,058 | 2,284 | 2,530 | 2,798 | 3,010 | 2,997 | |||
| Climber Specialist® | 1,052 | 983 | 929 | 959 | 1,729 | 1,755 | 1,828 | 1,766 | 1,737 | 1,912 | 1,709 | |||
| Aerial Lift Specialist® | 62 | 55 | 53 | 55 | 132 | 143 | 144 | 135 | 100 | 102 | 84 | |||
| Municipal / Urban Forest Prof* | 531 | 592 | 648 | 748 | 821 | 888 | 1,010 | 1,048 | 1,142 | 1,217 | 1,328 | |||
| Board Certified Master Arborist® ★ | 407 | 428 | 445 | 466 | 591 | 700 | 899 | 991 | 1,257 | 1,391 | 1,527 |
* Municipal Specialist (2012-2021) was replaced by Urban Forest Professional (2023+). Counts are shown as a continuous series.
'16 Climber/Aerial Lift jump = Western Chapter merger (+707 CS, +89 AL). '16 BCMA jump = exam relaunch (cut score 75% → 70%).
'16 Climber/Aerial Lift jump = Western Chapter merger (+707 CS, +89 AL). '16 BCMA jump = exam relaunch (cut score 75% → 70%).
Risk qualification
ISA Tree Risk Assessment Qualification (TRAQ)
| Metric | '12 | '13 | '14 | '15 | '16 | '17 | '19 | '21 | '23 | '24 | '25 | Trend | ||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| TRAQ Credential Holders | -- | 1,387 | 3,009 | 4,003 | 5,062 | 6,138 | 9,004 | 10,921 | 12,348 | 13,663 | 15,004 |
Launched April 2013. Not a certification; a qualification under ASTM E2659. Online renewal added 2021.
Application & exam volume
Credentialing pipeline & membership
| Metric | '12 | '13 | '14 | '15 | '16 | '17 | '19 | '21 | '23 | '24 | '25 | Range | Note | Trend |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Applications Received | -- | 3,598 | 3,940 | 5,231 | 5,075 | 5,662 | 5,389 | 6,056 | 6,151 | 7,773 | 5,775 | volatile | -26% YoY | |
| Exams Administered | -- | -- | 4,598 | 4,794 | 5,087 | 5,554 | 4,788 | 6,321 | -- | 8,461 | -- | +84% | sporadic | |
| ISA Membership | 21,083 | 20,988 | 21,690 | 21,992 | 22,988 | 23,805 | 23,704 | 25,455 | -- | -- | -- | +21% | '21 peak |