Part of the expanding PassProfessor catalog: this guide covers API’s API 653 Aboveground Storage Tank Inspector examination as API publishes it — 170 questions (140 scored, 30 unidentified pretest) in a 7.5-hour Prometric day, 110 closed-book and 60 open-book, passed at a scaled score of 400 on the 200 to 500 scale, and built to the effectivity pins for March 2027 to November 2027. PassProfessor’s companion practice program is in the works.
The program is in the works, built on the published Body of Knowledge for this examination. Join the notify list and we will email you when enrollment opens — then use this guide to plan your preparation area by area.
The API 653 credential is the tank inspector’s authorization: it certifies that an inspector can inspect, repair, alter, and reconstruct aboveground storage tanks under the API 653 standard and the reference publications API pins to the examination. This guide does the planning work in the open: verified facts, the pinned editions that define the current cycle — a cycle in which seven pins rolled forward at once — the Body of Knowledge area by area with a preparation method for each, scoring in API’s own terms, and a study plan. Everything factual comes from API’s published materials recorded in the internal sources section; where those materials direct candidates to confirm a current detail, the guide says so rather than printing an unverified figure.
Which examination is this?
This page covers one credential only: the API 653 Aboveground Storage Tank Inspector certification, administered by the American Petroleum Institute (API) through its Individual Certification Programs (ICP). It is not a guide to API 510 (pressure vessels) or API 570 (piping): each API program has its own Body of Knowledge and its own pinned editions — the damage-mechanism list, the article set, the welding-review limits, and several editions differ between programs, and this guide prints only this program’s. It is built to one cycle only: the Body of Knowledge and effectivity sheet for the March, July, and November 2027 examinations. Those pins govern the 2027 sittings. The November 2026 sitting tests to the prior cycle’s pins — this guide never presents the 2027 pins as governing it.
The real exam at a glance
| Fact of record | Detail |
|---|---|
| Credential | API 653 Aboveground Storage Tank Inspector, administered by API’s Individual Certification Programs (ICP); the program is ANSI-accredited under ISO/IEC 17024 |
| Format | 170 questions: 140 scored and 30 unidentified pretest questions that do not affect the score. 110 closed-book questions and 60 open-book questions |
| The exam day | 7.5 hours in total: a short tutorial, 165 minutes (2.75 hours) closed-book, a 45-minute lunch break, and 225 minutes (3.75 hours) open-book — 390 minutes of testing time |
| Delivery | Computer-based at Prometric test centers, in person only. API states expressly that the API 653 examination is not available for remote testing |
| References on the day | Papers, notes, and books are not allowed in the test center. During the open-book part only, PDF documents of the pertinent codes and standards are provided on the exam computer, limited to the sections listed on the effectivity sheet. A calculator, scratch paper, and pencil are provided |
| Item formats | The majority of questions are multiple-choice, single-answer. API is gradually adding Alternative Item Types — such as drag and drop, ordered response, multiple response, and matching — into its examinations |
| Scoring | Prometric reports a scaled score on a scale from 200 to 500. The passing scaled score is 400, as API publishes it. Score reports show the converted scaled score, not the number of questions answered correctly |
| Eligibility | Education plus tank experience acquired within the last 10 years, documented on the application and verified by API. No training course is required to sit the exam |
| Current cycle | Body of Knowledge and effectivity sheet for the March 2027, July 2027, and November 2027 examinations. Confirm current window dates and all fees at api.org when you apply |
| Application | Apply through API’s ICP Portal. An application is valid for 6 months from the first exam date requested. After approval, API issues an Exam Authorization with an Eligibility ID and the candidate books a Prometric seat inside the approved window |
| Examination fee | Confirm the current fee on API’s ICP Schedules & Fees page at api.org when you apply. This page prints no fee figure |
| Keeping the credential | Certification runs in 3-year terms, with work, continuing professional development, and a 6-year web quiz — see the recertification section below |
Which editions does the current cycle pin?
The effectivity sheet is the examination’s reading list with the editions fixed. For the March 2027 to November 2027 cycle, API pins the following — transcribed from the effectivity sheet itself, and the editions the companion practice program is built to:
- API RP 571, Damage Mechanisms Affecting Fixed Equipment in the Refining Industry, 3rd Edition (March 2020) — only Section 2 (Terms and Definitions) and ten listed mechanisms: atmospheric corrosion; brittle fracture; caustic corrosion; caustic stress corrosion cracking (caustic embrittlement); concentration cell corrosion; corrosion under insulation; ethanol stress corrosion cracking; microbiologically influenced corrosion; soil corrosion; and sulfuric acid corrosion. No other RP 571 mechanism is in scope.
- API RP 575, Inspection Practices for Atmospheric and Low-Pressure Storage Tanks, 5th Edition (September 2024), Addendum 1 (July 2025) and Addendum 2 (June 2026) — the whole document is applicable unless specifically excluded, and no exclusion is published.
- API RP 576, Inspection of Pressure-relieving Devices, 5th Edition (September 2024) with Addendum 1 (February 2026) — only Sections 4.3.2 and 6.7, and only as they concern weight-loaded pressure and vacuum vents on tanks.
- API RP 577, Welding Processes, Inspection, and Metallurgy, 3rd Edition (October 2020), Errata 1 (September 2025) — as printed on this program’s own current effectivity sheet.
- API Standard 650, Welded Tanks for Oil Storage, 14th Edition (August 2025) — in the related portions the Body of Knowledge references through API 653, with its listed annex exclusions.
- API RP 651, Cathodic Protection of Aboveground Petroleum Storage Tanks, 5th Edition (August 2024) — only Sections 1, 2, 3, 4, 5, 6, 8, and 11.
- API RP 652, Lining of Aboveground Petroleum Storage Tank Bottoms, 6th Edition (December 2025).
- API Standard 653, Tank Inspection, Repair, Alteration, and Reconstruction, 5th Edition (November 2014), Addendum 1 (April 2018), Addendum 2 (May 2020), Addendum 3 (November 2023), Addendum 4 (July 2025), Errata 1 (March 2020), and Errata 2 (February 2025) — the whole document is applicable unless specifically excluded, and no section exclusion is published.
- ASME Boiler and Pressure Vessel Code, 2025 Edition — limited to Section V, Nondestructive Examination, Articles 1, 2, 6, 7, and 23 (Section SE-797 only); and Section IX, welding only. Brazing is not covered.
Seven pins rolled forward from the prior cycle at once, and candidates holding older study material should note every one: API Standard 650 moved from the 13th Edition to the 14th; API RP 652 moved from the 5th Edition to the 6th; the ASME BPVC moved from the 2023 Edition to the 2025 Edition; API 653 gained Addendum 4; RP 575 gained Addenda 1 and 2; RP 576 gained Addendum 1; and RP 577 gained Errata 1 — which the prior cycle’s sheet for this program did not list. The mechanism list did not change in this step; it changed one step earlier, and study lists that still teach chloride stress corrosion cracking, mechanical fatigue, or sour water corrosion as current tank-examination mechanisms are teaching a superseded list. The Body of Knowledge also gained tank-specific changes that follow the rolled editions: joint-efficiency tables in split form, renumbered weld-size and settlement figures, an expanded bottom-plate topic, and a stated expectation that starred-table values may be tested closed-book. The exclusions matter as much as the inclusions: no repair-methods code, no material verification program, no pressure-vessel construction section, and no process piping or flange standard — that content belongs to the other API programs and is out of scope here. Within the pinned library: cathodic-protection design and interference-current content are excluded; the penetration-examination article carries one mandatory appendix, not two; two named paragraphs of the magnetic-particle article are excluded; and a long list of construction-standard annexes is excluded or limited. A recertification effectivity sheet dated April 2023 still circulates pinning superseded editions — it scopes the 6-year web quiz only.
Who can take this exam, and what does it certify?
Qualification combines education with experience related to aboveground storage tanks. The experience must have been acquired within the last 10 years while employed by, or under contract with, an authorized inspection agency as defined in API 653; it must be documented on the application, and API verifies it. As API publishes the table: a bachelor’s degree or higher in engineering or technology — or 3 or more years of military service in a technical role — requires 1 year of supervision or performance of inspection activities as described in API 653. A 2-year degree or certificate in engineering or technology — or 2 years of military service in a technical role — requires 2 years of design, construction, repair, operation, or inspection of aboveground storage tanks, 1 of them in API 653 inspection activities. A high school diploma or equivalent requires 3 years on the same terms. With no formal education, 5 or more years are required. Each includes the same inspection year. No training course is required to sit the exam, and API does not endorse test-preparation classes. The credential is awarded by API alone; PassProfessor does not certify inspectors and does not enrol candidates — candidates apply through API’s ICP Portal and sit at Prometric.
What makes this test demanding?
Three features make this examination harder than a single-code test. First, the two-part structure: 110 closed-book questions test what an inspector is expected to know cold — intervals, responsibilities, inspection types, damage-mechanism recognition, welding and examination essentials, stated factors and rules, and starred-table values — then, after a lunch break, 60 open-book questions test how well the same inspector can find and apply detailed information under time pressure, in a provided-PDF environment limited to the effectivity sheet’s sections. Second, the calculation load: corrosion rates, remaining life, shell minimum thickness, corroded-area and pitting evaluations, fill height, bottom-plate values, and settlement evaluations are worked, not recalled. Third, the breadth of the pinned library, each publication included only to a stated depth — the exclusions are part of the syllabus. Sustained practice mixing closed-book recall, record review, and open-book-style application is therefore the centre of serious preparation.
The outline, area by area
API’s Body of Knowledge has five sections: calculations and tabular evaluations for evaluating thickness measurements, weld sizes, and tank integrity; welding on atmospheric aboveground storage tanks; nondestructive examination; practical knowledge — general; and practical knowledge — specific, publication by publication. API publishes no weighting for this examination — no percentage or question count per topic. The nine areas below divide the practice bank; their counts are a PassProfessor allocation, set in proportion to the Body of Knowledge’s emphasis, and they are never API’s weighting.
| Practice area | Practice questions |
|---|---|
| Thickness, Intervals and Tank Integrity Calculations | 320 |
| API 653 Inspection, Repair, Alteration and Reconstruction | 240 |
| Nondestructive Examination | 170 |
| Welding Procedure and Qualification Evaluation | 150 |
| Damage Mechanisms (API RP 571) | 140 |
| Inspection Practices and Pressure/Vacuum Relief | 140 |
| Foundations, Settlement and Practical Knowledge | 140 |
| Cathodic Protection and Tank Bottom Linings | 110 |
| Welding Processes and Metallurgy (API RP 577) | 90 |
| Total | 1,500 |
What do the thickness, interval, and tank integrity calculations cover?
Metal loss, including corrosion averaging; corrosion rate; remaining life; remaining corrosion allowance; inspection interval determination, internal and external; joint efficiency determination from joint types and the type and extent of radiography, read from the split joint-efficiency tables; maximum fill height and minimum allowable thickness; weld sizes for shell and roof openings, from the construction standard’s renumbered figures and tables; hot tap minimum spacing; settlement evaluation — edge settlement, bottom settlement near the shell, and localized settlement remote from the shell — and the number of settlement survey points; impact testing determinations; existing tank shell minimum thickness, working from allowable stress, joint efficiency, and liquid height; reconstructed tank shell minimum thickness, in its design and hydrostatic-test forms; corroded-area evaluation and pitting evaluation; bottom plate minimum thickness, minimum remaining thickness, and maximum period of operation — the last formulas are provided in the examination, and the bottom-plate table values are starred for closed-book use; replacement plate dimensions; and lap-welded patch plates. Calculation questions are oriented to existing tanks, in both unit systems.
How should you prepare for the calculations? Work them, in both unit systems, until the sequence is automatic. Learn the starred-table values as knowledge in themselves — the current Body of Knowledge expects them without a document in hand — and keep the excluded families out of your drilling: required thickness for wind, earthquake, and small internal pressures, nozzle loads, flange calculations, venting, structural work, and cathodic-protection design are not tested calculation families here.
Remaining life is the hinge number: most interval and repair decisions turn on computing it correctly.
What does the API 653 standard area cover?
The standard itself, applied: how inspection is organized, the certification requirements behind the credential, inspection types and planning; external and internal inspection, intervals, and suitability for continued service; repairs and alterations — foundations, shell, bottoms, nozzles, roofs, seals, and hot taps; reconstruction, change of service, nameplate, and record requirements; hydrostatic, leak, and pneumatic testing; and the construction-standard knowledge that applies to existing tanks. API 653 itself is subject to testing in full — no section exclusion is published for it.
How should you prepare for the API 653 standard area? Study it as decisions, not as text: given this finding, this history, and this tank, what does the standard require next — inspect, repair, alter, reconstruct, test, or return to service — and who is responsible for each step?
A tank is judged as a system: shell, bottom, and settlement findings on the same tank change each other’s meaning.
What does nondestructive examination cover?
The general requirements article of Section V; radiographic examination as applied to tank butt welds; liquid penetrant examination, including the one mandatory appendix this program names; magnetic particle examination, limited to the yoke and prod techniques and excluding two named paragraphs; ultrasonic thickness measurement under the SE-797 section; and the general examination requirements carried in the construction standard and API 653. There is no visual-examination article and no leak-testing article in this program’s set — a real difference from the piping program’s set, and a common source of imported error.
How should you prepare for nondestructive examination? Learn each method as a pairing of capability and limit: what it finds, what it cannot find, and what it requires of the surface and the material.
Match the method to the discontinuity and the material: a sound method for the wrong condition is the favoured distractor.
What does welding procedure and qualification evaluation cover?
Welding procedure specifications, procedure qualification records, and welder performance qualifications checked for compliance — under the narrowest limits of the three API programs in this family: two named processes only, a single base-metal group, one process per record set, one filler metal per process, a single supporting qualification record, no dissimilar-metal joints, no overlay, hard-facing, or buttering, no impact-test requirements or supplementary essential variables on examination records, and no heat-treatment requirements on any examination procedure or qualification. Alongside the review sit essential and nonessential variables and the mechanical tests, and the general welding requirements in the construction standard and API 653. The procedure must reference its supporting qualification, and the qualification record must be signed and dated.
How should you prepare for welding qualification? Practise reading records against the variables: cover the record, name the essential variables the described weld engages, then check. The skill is spotting the one change that outruns the supporting qualification.
A record can be complete, signed, and still wrong: the deciding feature is a variable beyond what the qualification covers.
What do damage mechanisms cover?
API RP 571’s terms and definitions section, and the ten mechanisms listed in the pinned-editions section above — no others. The list is this program’s own, and its recent history is the trap: the step before the current one dropped three widely taught mechanisms and added two found on neither neighbouring program’s list. Mechanisms pinned for the vessel or piping programs — amine stress corrosion cracking, hydrochloric acid corrosion, and wet hydrogen sulfide damage among them — are out of scope here.
How should you prepare for damage mechanisms? Study each mechanism as a four-part signature — susceptible materials, the environment that drives it, the temperature and stress conditions it needs, and where the damage appears — because examination items present three or four of those features and ask the candidate to complete the identification, or present the mechanism and ask where an inspector looks for it.
Mechanism items turn on the combination: material, environment, temperature, and stress together.
What do inspection practices and pressure/vacuum relief cover?
API RP 575, inspection practices for atmospheric and low-pressure storage tanks — the whole document — and API RP 576 in two sections only, as they concern weight-loaded pressure and vacuum-relief valves and vents on tanks: their inspection, testing, maintenance, and setting. The relief-device scope here is tank venting only.
How should you prepare for inspection practices and relief? Prepare in the field’s order: what is examined, in what sequence, with what evidence recorded, and what finding triggers what action.
A tank’s vent is part of its integrity case, not an accessory: inspection findings on the vent carry the same weight as findings on the shell.
What do foundations, settlement, and practical knowledge cover?
Tank foundations, distortions, and settlement in practical evaluation — edge settlement, bottom settlement near the shell under the renumbered figures, and localized settlement remote from the shell; materials, fabrication problems, and brittle fracture risk; roofs, seals, appurtenances, and auxiliary equipment evaluation; and inspection safety, tools, leak checks, and causes of deterioration.
How should you prepare for foundations and settlement? Learn settlement as pattern recognition: the same measured movement means different things at the shell, near it, and remote from it, and the evaluation follows the location and shape of the movement.
Settlement is read as a pattern, not a number: where the tank has moved decides what the movement means.
What do cathodic protection and tank bottom linings cover?
API RP 651, cathodic protection of aboveground petroleum storage tanks, in Sections 1, 2, 3, 4, 5, 6, 8, and 11 only — with the design of cathodic protection systems and the sources, detection, and control of interference currents expressly excluded — and API RP 652, lining of aboveground petroleum storage tank bottoms, across the whole document in its current edition. Together they cover the tank bottom’s two faces: soil-side protection from below, product-side lining from above.
How should you prepare for cathodic protection and linings? Prepare the evaluation, not the design: what evidence shows a protection system is working, what a lining’s condition and service history tell an inspector, and what findings require action.
Soil-side corrosion is the failure the inspector cannot see directly: this area tests the evidence that stands in for sight.
What do welding processes and metallurgy cover?
API RP 577 across the whole document as pinned for the current cycle — 3rd Edition with Errata 1, the errata being part of this cycle’s roll-forward for this program — and the supporting knowledge the Body of Knowledge groups with it: filler metal selection, terminology and symbols, and radiographic result reporting.
How should you prepare for welding processes and metallurgy? Keep process knowledge and verification discipline separate: what each process does and how its welds are inspected on one side, precise terminology and reporting on the other.
Process knowledge is what lets an inspector read a weld.
How is API 653 scored?
API publishes the standard as a scaled score. Prometric uses a scale from 200 to 500 for API’s Individual Certification Programs examinations, and the passing scaled score for the API 653 examination is 400. A scaled score is not a percentage of questions answered correctly, and API publishes no percentage pass mark, no raw pass mark, and no number-correct threshold for this examination. API’s equating adjusts for form difficulty, so the number of correct answers corresponding to the passing scaled score may differ slightly between forms. Score reports show the converted scaled score, not the number answered correctly; reports are emailed by Prometric within 24 hours of testing, and results upload to the ICP Portal within 3 business days. API will not disclose or return the contents of a failed examination. The practical consequence: there is no published percentage to aim practice at, and any percentage a vendor attaches to this examination is that vendor’s invention. Aim at breadth and reliability instead — the scaled standard is a fixed level of minimum knowledge, not a curve.
How do inspectors keep the credential?
Certification is valid for a 3-year term. At each recertification the inspector shows two things: work — a minimum of one fifth of working time over the most recent 3-year period spent performing or supervising aboveground storage tank inspection activities as described in API 653 (inspectors not actively engaged must take the full examination again); and continuing professional development — 24 CPD hours per 3-year cycle, relevant to inspection and mechanical integrity, spread across at least two categories, with proof uploaded to the ICP Portal. Recertification is applied for online in the ICP Portal, from 90 days before expiry through a 90-day grace period after it; late fees apply after expiry, and an inspector who has not applied by the end of the grace period must take a full examination again. Every 6 years — every other recertification — the inspector must also pass an online, open-book web quiz on changes to the relevant codes: 25 questions in 4 hours, pausable up to three times, available in the same window around expiry; failing once allows a retake, failing a second time ends recertification. The web quiz is scoped by a separate recertification effectivity sheet, still pinning superseded editions and the superseded mechanism list — never conflate the two. Since June 2025, API issues its ICP certifications digitally.
An honest note on format
Every PassProfessor practice question is a single-answer, four-option item. The real examination’s majority format is also multiple-choice, single-answer — but API is gradually adding Alternative Item Types (drag and drop, ordered response, multiple response, and matching), the real sitting splits into closed-book and open-book parts, and the open-book part runs in Prometric’s provided-PDF environment, limited to the effectivity sheet’s sections. Practice here does not reproduce that environment, those item types, or the two-part sitting, and no honest provider can claim that it does. Practice builds the knowledge and calculation skills the Body of Knowledge requires; results are a study gauge, not a prediction of a scaled score, and no practice percentage converts into one.
How should you read your practice results?
An overall practice score is the least useful number a candidate owns. The useful reading is by area: which areas are secure, which are inconsistent — right on recall, wrong on record review or calculation — and which are simply thin. Each pattern has a different repair. A secure area needs only maintenance in mixed practice. An inconsistent area usually means one skill inside it is lagging and needs slower, worked practice on that skill. A thin area needs study in the pinned publication before drilling, because drilling untaught material rehearses guessing. Revisit each repaired area after a gap of several days, in mixed practice, so retention — not recognition — carries the result. Read the two examination styles separately: a candidate can be strong closed-book and weak at open-book-style application, and the repairs differ.
A study plan that follows the outline
- Start with the calculations. Thickness, intervals, and tank integrity carry the practice bank’s largest allocation because the Body of Knowledge’s required skills are densest there — and calculation fluency supports the areas that use its results.
- Take the API 653 standard area next, then work area by area, drilling as you go. Take each area’s practice after studying it and repair misunderstandings while the material is fresh.
- Read results by area, not just by score. A single overall figure hides the thin area; on a two-part examination it also hides which sitting style — closed-book or open-book — is costing you.
- Hold the pinned editions open beside you for open-book-style work — and drill the starred tables closed-book. Practise finding and applying, not only remembering: know which publication, and which part of it, answers each kind of question — and know the starred-table values without the document.
- Finish with full simulations. Sit timed practice at the real sitting’s total testing time, in both styles — and confirm your window dates and fees at api.org as you apply.
Frequently asked questions
How many questions are on the API 653 exam, and how long is it? 170 questions in a 7.5-hour day: 140 scored and 30 unidentified pretest questions that do not affect the score, split into 110 closed-book questions in 165 minutes and 60 open-book questions in 225 minutes, with a 45-minute lunch break between the parts.
What score passes the API 653 exam? A scaled score of 400 on Prometric’s 200 to 500 scale, as API publishes it. A scaled score is not a percentage of questions answered correctly; API publishes no percentage pass mark and no number-correct threshold, and the number of correct answers corresponding to the passing scaled score may differ slightly between forms because of equating.
Can I take the API 653 exam from home? No. API states expressly that this examination is not available for remote testing; it is taken in person at a Prometric test center.
What references can I use during the exam? None of your own — papers, notes, and books are not allowed in the test center. During the open-book part only, PDF documents of the pertinent codes and standards are provided on the exam computer, limited to the specific sections listed on the effectivity sheet. A calculator, scratch paper, and pencil are provided.
Which editions does the current exam test? The editions pinned on the effectivity sheet for the March 2027 to November 2027 cycle: RP 571, 3rd Edition, Section 2 and ten listed mechanisms only; RP 575, 5th Edition with Addenda 1 and 2; RP 576, 5th Edition with Addendum 1, in two sections only; RP 577, 3rd Edition with Errata 1; API Standard 650, 14th Edition; RP 651, 5th Edition, in limited sections; RP 652, 6th Edition; API Standard 653, 5th Edition with Addenda 1 to 4 and Errata 1 and 2; and the ASME Boiler and Pressure Vessel Code, 2025 Edition, in the stated sections. The pinned-editions section above gives the full list. Those pins govern the 2027 sittings; the November 2026 sitting tests to the prior cycle’s pins.
Does API publish how the exam is weighted by topic? No. API publishes no weighting, percentage, or per-topic question count for this examination. The area counts in this guide are a PassProfessor allocation of the practice bank, set in proportion to the Body of Knowledge’s emphasis — they are not API’s weighting.
What experience do I need to qualify? Education plus tank experience acquired within the last 10 years with an authorized inspection agency, documented and verified by API: 1 year of inspection activity with an engineering or technology degree (or the military-service equivalent), rising through 2 and 3 years at the lower education levels, to 5 or more years with no formal education — in each case including the inspection year where the table requires it.
How often is the exam offered? In windows across the year — three windows a year on the published pattern. The current cycle covers the March 2027, July 2027, and November 2027 windows. Confirm the current window dates and application deadlines at api.org when you apply.
What does the exam cost? Confirm the current fee on API’s ICP Schedules & Fees page at api.org when you apply — fees are confirmed there at application time, and this guide prints no fee figure.
What happens if I do not pass? Your score report — emailed by Prometric within 24 hours — shows your converted scaled score, so you can see the distance from the passing standard. API will not disclose or return the contents of a failed examination. An application is valid for 6 months from the first exam date requested; sitting again outside it requires a new application.
How do I keep the credential once I earn it? Recertify every 3 years in the ICP Portal: show the published work requirement and 24 continuing professional development hours across at least two activity categories per cycle, and pass the online open-book web quiz on code changes every 6 years.
Are these the real exam questions? No. Every question in the companion program is an original PassProfessor practice question written to API’s published Body of Knowledge. API does not release its examination questions, and no provider can offer them.
Does the practice match the real exam’s format exactly? No, and this guide does not claim that it does. Practice items are single-answer, four-option questions in a single sitting; the real examination also includes Alternative Item Types being added gradually, and splits into closed-book and open-book parts in Prometric’s provided-PDF environment.
When will enrollment open? The program is in the works. Join the notify list on this page and we will email you when enrollment opens.
Disclaimer
PassProfessor is an independent exam-preparation provider; this program is not endorsed by, affiliated with, or sponsored by the American Petroleum Institute (API). API 653 is a certification program of the American Petroleum Institute. This program is examination preparation only: the details on this page are drawn from the official sources recorded in this guide’s internal sources section and are current as of November 2026; API’s official publications govern if anything here differs from them. The credential is awarded by API alone when its requirements are complete; this program confers no credential.