The three certifications
All three exams have the same format: 170 questions (140 scored), 110 closed book and 60 open book, over a 7.5-hour day at a Prometric test center.
| Certification | Covers | 2027 exam windows |
|---|---|---|
| API 510 | In-service pressure vessels | January 2-22, May 7-28, September 3-24 |
| API 570 | In-service piping systems | January 29-February 19, June 4-25, October 8-29 |
| API 653 | Aboveground storage tanks | March 12-April 2, July 9-30, November 5-26 |
Who can apply
The requirements are the same pattern for all three, with experience in the matching equipment (pressure vessels, piping or tanks) gained in the last 10 years while employed by, or under contract with, an authorized inspection agency:
- BS or higher in engineering or technology, or 3+ years of technical military service: 1 year supervising or performing inspection under the code.
- 2-year degree or certificate in engineering or technology, or 2 years of technical military service: 2 years in design, fabrication or construction, repair, operation or inspection, of which 1 year in inspection.
- High school diploma or equivalent: 3 years, of which 1 year in inspection.
- No formal education: 5 or more years, of which 1 year in inspection.
Step by step
- Check you meet the education and experience requirements for the certification you want, with supervisors who can verify it.
- Apply in API's ICP Portal before the window's application deadline (about two months before the window; late applications cost US$200 more).
- When API approves the application you get an Exam Authorization email with an Eligibility ID.
- Schedule your exam at a Prometric test center within your assigned window.
- Study the editions on that window's effectivity sheet, then practice exam-style questions and full timed mocks.
- Sit the exam. Prometric emails score reports within 24 hours, and certificates are issued digitally.
See where you stand in 10 minutes
Take the free API 510 practice test. 15 questions, every answer explained.
What it costs
API's fee for API 510, 570 or 653 is US$875 for API members and US$1,125 for non-members in its 2026 fee table, and US$890 and US$1,140 in its 2027 table. Rescheduling costs US$350 and a late application US$200. You'll also need the code documents (or access through your employer) and any preparation you choose. Check the current fees on API's website before you apply.
Keeping the certification
- Certification lasts three years. Apply for recertification in the ICP Portal from 90 days before expiry (90-day grace period, late fees apply).
- Show that at least 20% of your time over the three years was spent performing or supervising inspection under that code.
- Complete 24 continuing professional development (CPD) hours in each three-year cycle.
- Take API's 25-question online open-book quiz every six years.
Frequently asked questions
Which API inspector certification should I take first?
Take the one that matches your work: API 510 for pressure vessels, API 570 for piping, API 653 for tanks. Many inspectors later add a second one; the welding, NDE and damage-mechanism content overlaps.
How long does it take to get certified?
Allow three to six months from application to exam: applications close about two months before the window, and most candidates study for 8 to 12 weeks.
Can I retake the exam if I fail?
Yes. API gives each candidate 12 consecutive months, starting from the first scheduled exam date, to pass. To sit a later window within that period you file a Reschedule/Retest application in the ICP Portal (US$350 for API 510, 570 and 653). After 12 months you need a new application and the full fee.
Are API 510, 570 and 653 recognized outside the United States?
Yes. API certifications are used by owners and inspection agencies worldwide, and API offers translated exams (Spanish and Chinese for all three, Korean for API 510 and 570) on request.
Official sources
- API: Individual Certification Programs
- API: ICP Schedules & Fees
- API: ICP Certification Applications
- API: API 570 Piping Inspector
- API: API 653 Aboveground Storage Tank Inspector
Practice tests for these certifications
API 510 Pressure Vessel Inspector Exam
The API certification exam for in-service pressure vessel inspectors, based on API 510 and the documents on the effectivity sheet.
API 570 Piping Inspector Exam
The API certification exam for in-service piping inspectors, based on API 570, ASME B31.3, ASME B16.5 and the other documents on the effectivity sheet.
API 653 Aboveground Storage Tank Inspector Exam
The API certification exam for aboveground storage tank inspectors, based on API 653, API 650 and the other documents on the effectivity sheet.
This guide is general information, checked November 2026, not legal advice. API rules change; confirm with API before you apply.
