API 510 / 570 / 653 Pass Rate 2026 — API's Published Statistics + Why Candidates Fail

API 510 / 570 / 653 Pass Rate 2026 — What API's Own Statistics Show

"What is the API exam pass rate?" is one of the most common questions from API ICP candidates. Unlike many certification bodies, API does publish exam statistics: its Individual Certification Programs status updates include per-window candidate counts, passes, fails and pass percentages for API 510, 570 and 653. This page summarises the most recent update we have reviewed (ICP Status Update, breakdown as of 30 April 2025, covering computer-based exams through March 2025). Check the ICP statistics page on api.org for newer reports.

Per-Window Pass Rates Reported by API (2020 - early 2025)

Certification	Range of per-window pass rates	Recent windows	Pass point
API 510 Pressure Vessel Inspector	About 54% to 69%	Mid-to-high 60s in 2024 and January 2025	Scaled score 400
API 570 Piping Inspector	About 45% to 70%	Mostly 60s in 2023-2025	Scaled score 400
API 653 Aboveground Storage Tank Inspector	About 62% to 76%	Low-to-mid 60s and 70s in 2024-2025	Scaled score 400

Source: API ICP Status Update (April 2025), "Historical Exam Performance" tables. API notes that API 510 and 653 underwent standard settings in November 2019 and API 570 in November 2020, and that COVID-19 disrupted the March-May 2020 windows. Pass percentages are per exam window, all candidates; API does not split them into first attempt vs retake, by region, or by preparation method, so any such breakdown you see elsewhere is an estimate, not API data.

What the Numbers Mean

• Roughly one in three candidates does not pass in a typical recent window, so planning for a possible retest is sensible.
• Rates move several points between windows; do not read much into a single window.
• All three exams use the same format: 170 questions (140 scored), 110 closed-book plus 60 open-book, about 7.5 hours at Prometric test centers. Remote proctoring ended in September 2024.

Common Reasons Candidates Fall Short

API does not publish failure analysis, so the following is practical guidance from inspectors rather than statistics:

• Open-book navigation speed. 60 open-book questions in 3.75 hours leaves under four minutes each. Index the referenced documents in the editions on the effectivity sheet.
• Calculations. Corrosion rate, remaining life, inspection intervals, MAWP and construction-code thickness formulas (ASME VIII for 510, B31.3 for 570, API 650/653 for 653).
• Damage mechanisms. Only the RP 571 paragraphs listed on each effectivity sheet are examined; learn those thoroughly.
• Studying the wrong documents. API 579 (FFS) and API RP 580/581 (RBI) are not on the 510, 570 or 653 BOKs; time spent on RBI or FFS calculations is time taken from documents that are examined.
• Time management. Practise full-length timed runs.

Comparing With Other Inspection Exams

Pass rates are not directly comparable across bodies because formats, scoring and candidate pools differ. If you want a comparison, use each body's own published statistics (for example API's ICP reports or AWS and ASNT publications where available) rather than aggregated estimates.

Atlantis NDT does not run API 510, 570 or 653 exam-preparation courses and publishes no pass rate of its own. See the free API 510, API 570 and API 653 Body of Knowledge summaries.

Frequently Asked Questions

Q1: Does API publish official pass rates?

A: Yes. API's ICP status updates include historical exam-performance tables with per-window pass percentages for each program.

Q2: Does region of exam matter for the pass rate?

A: API does not publish pass rates by region. The exam content and format are the same at every Prometric center.

Q3: Does API 653 have a lower pass rate than API 510?

A: Not in API's 2020-2025 figures; API 653 windows were generally in a similar or slightly higher band than API 510.

Q4: What is the pass mark?

A: API uses scaled scoring with a pass point of 400; it does not publish a percent-correct equivalent.

Q5: Is the exam open-book?

A: Partly: 110 closed-book questions, then 60 open-book questions with references provided electronically.

Q6: What happens if I fail?

A: Submit a reschedule/retest application with the retest fee and sit in a later window; check api.org for current rules.

Q7: How quickly do I get results?

A: API states that Prometric emails a score report, typically within 24 hours, and final results are uploaded to the ICP portal afterwards.

Q8: Do I need ASNT Level III to sit these exams?

A: No. Eligibility is education plus equipment-related inspection experience.

Related Atlantis NDT Resources

• ASNT certification — Level I/II/III pathway, pass rates, employer recognition
• API 510 Pressure Vessel Inspector · API 570 Piping Inspector · API 653 Tank Inspector
• API 510 BOK 2026 · API 570 BOK 2026 · API 653 BOK 2026
• ASNT Level III consulting — outsourced Level III of record with SLA
• NDT reporting software — digital NDT inspection reports
• Atlantis NDT ERP — affordable, accessible, fully customizable
• Atlantis Digital Twin platform — 3D inspection-data overlay, predictive maintenance

Atlantis NDT is led by Anoop Rayavarapu (ASNT NDT Level III, multi-method). Free consultation for NDT inspection companies, training providers, and asset owners worldwide. request a free consultation. Pricing varies by region and scope, quote on request.