API 653 exam guide: format, Body of Knowledge and fees
API 653 certification from the American Petroleum Institute's Individual Certification Programs is for inspectors of atmospheric aboveground storage tanks. Like API 510 and API 570, the exam has a closed-book part and an open-book part, and it rewards inspectors who can set up a tank calculation without looking anything up and find a code section fast when they may.
- Questions
- 170
- Time
- 390 minutes
- Where
- In person at designated test centers only
The exam in brief
- Format: 170 questions, 140 scored and 30 pretest. The first 110 are closed book; the last 60 are open book.
- Time: 390 minutes of testing.
- Open-book part: PDFs of the codes and standards are on screen, and only the sections named on the Publications Effectivity Sheet for your window are used for questions. Papers and books are not allowed in the test center.
- Where you test: in person at designated test centers, during set exam windows.
- Passing: a scaled score of 400 on a 200 to 500 scale. Unanswered questions are marked wrong.
- Fees: API's 2027 fee table lists $890 for members and $1,140 for non-members, and its 2026 table lists $875 and $1,125.
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V. Practical knowledge - specific (API 653 and 650, RP 571 listed mechanisms, RP 575, RP 576, RP 577, RP 651, RP 652)
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The five Body of Knowledge sections
API's Body of Knowledge splits the exam into five sections and publishes no weights, so prepare every one:
- Calculations and tabular evaluations for thickness measurements, weld sizes and tank integrity.
- Welding on atmospheric storage tanks: ASME Section IX, API 650 Section 9 and API 653 Section 11.
- Nondestructive examination: ASME Section V, API 650 Section 8 and API 653 Section 12.
- Practical knowledge, general.
- Practical knowledge, specific: API 653 and API 650, the RP 571 mechanisms listed, and RP 575, RP 576, RP 577, RP 651 and RP 652.
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Which editions apply
The effectivity sheet for your window sets the editions. The 2026 sheet lists API 650 13th edition and the 2023 ASME code; the 2027 sheet lists API 650 14th edition and the 2025 ASME code. Check the sheet for your exam date before you study from any book. Weighing API 653 against the vessel and piping exams? Read API 510 vs 570 vs 653.
Who can apply
API asks for experience within the last 10 years, set by your education under Annex D of API 653: one year of supervising or performing inspection with an engineering or technology degree, two years of tank work including one of inspection with a two-year degree, three years with a high school diploma, or five or more years with no formal education.
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Sources
Show the list
- API 653 certification page, American Petroleum Institute, read 21 October 2026.
- API 653 Body of Knowledge, March 2026, American Petroleum Institute, read 21 October 2026.
- Schedules and fees, American Petroleum Institute, read 7 November 2026.
Exam facts
| Questions | 170 total (140 scored + 30 pretest); 110 closed-book + 60 open-book |
| Time | 390 minutes |
| Book | Closed-book part, then open-book part. PDFs of the pertinent codes and standards are on screen in the open-book part, and papers and books are not allowed in the Prometric centers. The BOK says only the sections of publications named on the Publications Effectivity Sheet are used for questions |
| Calculator | Calculator on screen; a handheld calculator on request from the proctor at an in-person center; scratch paper and pencil provided. Calculator type (basic or scientific) not stated |
| Passing | Scaled score 400 on a 200-500 scale (equated across forms). Unanswered questions are marked incorrect; no partial credit on multiple-response or matching questions |
| Where you test | In person at designated test centers only |
| Code edition | 2026 sheet (March, July, November 2026 exams): API 653 5th ed. Nov 2014 with Addenda 1 to 3 and Errata 1 and 2; API 650 13th ed. Mar 2020 with Errata 1; RP 571 3rd ed. Mar 2020 (listed mechanisms only: Section 2 and paragraphs 3.8, 3.11, 3.14, 3.15, 3.19, 3.22, 3.28, 3.45, 3.57, 3.62); RP 575 5th ed. Sep 2024; RP 576 5th ed. Sep 2024 (4.3.2 and 6.7 only); RP 577 3rd ed. Oct 2020; RP 651 5th ed. Aug 2024; RP 652 5th ed. May 2020; ASME BPVC 2023 (V Articles 1, 2, 6, 7 and 23 SE-797 only; IX welding only). 2027 sheet (March, July, November 2027 exams) changes: API 653 adds Addendum 4 (Jul 2025); API 650 14th ed. Aug 2025; RP 575 adds Addenda 1 and 2; RP 576 adds Addendum 1 and cites 6.6; RP 577 adds Errata 1; RP 652 6th ed. Dec 2025; ASME BPVC 2025; joint efficiency Tables 4.2a and 4.2b |
| Eligibility | Experience within the last 10 years with an authorized inspection agency, per Annex D of API 653: BS engineering/technology (or 3+ yrs military technical) = 1 yr supervision or performance of inspection activities; 2-yr degree or certificate (or 2 yrs military) = 2 yrs design, construction, repair, operation or inspection of aboveground storage tanks, incl. 1 yr inspection; high school = 3 yrs; no formal education = 5+ yrs |
| Renewal | Every 3 years: at least 20% of time on aboveground storage tank inspection in the last 3 years, 24 h CPD per cycle; 25-question open-book web quiz every 6 years (4 hours, one retake) |
Fee details
Initial: 2026 Fees tab $875 member / $1,125 non-member; 2027 Fees tab $890 / $1,140. Recertification: 2026 $745 / $855; 2027 $760 / $870. Late application $200. Reschedule (new window) $350
What the exam covers
| I. Calculations and tabular evaluations for thickness measurements, weld sizes and tank integrity | not published by American Petroleum Institute |
| II. Welding on atmospheric aboveground storage tanks (ASME IX, API 650 Section 9, API 653 Section 11) | not published by American Petroleum Institute |
| III. Nondestructive examination (ASME V, API 650 Section 8, API 653 Section 12) | not published by American Petroleum Institute |
| IV. Practical knowledge - general | not published by American Petroleum Institute |
| V. Practical knowledge - specific (API 653 and 650, RP 571 listed mechanisms, RP 575, RP 576, RP 577, RP 651, RP 652) | not published by American Petroleum Institute |
American Petroleum Institute lists these sections but publishes no weights, so treat them as equally important until you know otherwise.
Sources
Show the 5 sources
- api.org/products-and-services/individual-certification-programs/certifications/api653 (checked 2026-10-21)
- api.org/products-and-services/individual-certification-programs/schedules-and-fees (checked 2026-11-07)
- api.org/-/media/Files/Certification/ICP/ICP-Certification-Programs/653/2026%20files/March% (checked 2026-10-21)
- api.org/-/media/Files/Certification/ICP/ICP-Certification-Programs/653/2026%20files/March% (checked 2026-10-21)
- api.org/products-and-services/individual-certification-programs/schedule-exams (checked 2026-11-07)
Facts come from American Petroleum Institute's own documents (sources above); the latest source retrieval was . If something has changed, tell us and we will correct it within 2 business days.
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