- A CHP is credentialed by the ABHP within the AAHP after passing two separate exams.
- Part I is 150 multiple-choice questions in 3 hours; the cut score is typically around 95 correct.
- Part II is a 6-hour closed-reference exam requiring 469 of 700 points, with six core plus four of eight specialty questions.
- Part II eligibility requires six years of health physics experience, including three years applied, plus a radiation protection report.
What Is a CHP?
A Certified Health Physicist (CHP) is a radiation safety professional who has demonstrated, through a rigorous two-part examination process, mastery of the science and practice of protecting people and the environment from the harmful effects of ionizing radiation. The letters "CHP" after someone's name signal that they have met a defined standard of education, professional experience, and tested competency - not simply that they hold a job title. If you're researching this credential from scratch, our companion piece on What Is CHP? covers the broader landscape, while this article focuses specifically on the person behind the letters and what it actually takes to earn them.
Health physicists work in nuclear power, medical radiation safety, environmental monitoring, academic research, federal regulation, and defense. The CHP credential is the profession's recognized mark of expertise, similar in function to a professional engineering license but built around radiation protection specifically. For a deeper breakdown of the acronym itself and how people commonly use or misuse it, see CHP Meaning and What Does CHP Stand For?.
Who Credentials the CHP
The CHP credential is issued by the American Board of Health Physics (ABHP), which operates under the umbrella of the American Academy of Health Physics (AAHP). The ABHP sets exam content, scoring standards, and eligibility rules, while the AAHP oversees the broader professional structure, including continuing education requirements for recertification. This two-body structure matters because it explains why certification (passing the exam) and membership in good standing (maintaining AAHP status) are treated as separate but linked obligations for anyone who wants to keep using the CHP designation long-term.
Unlike some certifications that are administered entirely by a single testing vendor, the CHP process blends a computer-based exam delivered through Pearson VUE (Part I) with a written, closed-reference exam developed and graded by ABHP-appointed panelists (Part II). This hybrid approach is one reason the credential is respected industry-wide: it tests both foundational knowledge and applied professional judgment.
The Two-Part CHP Exam Structure
Becoming a CHP requires passing two distinct exams, and understanding their mechanics is essential before you commit time or money to the process. If you want a full walkthrough of difficulty expectations, our guide on How Hard Is the CHP Exam? goes deeper, but here's the structural overview.
Part I: The Comprehensive Exam
- Delivered as a computer-based test through Pearson VUE testing centers
- 150 five-option multiple-choice questions
- 3-hour time limit
- Cut score is statistically set and has typically landed around 95 correct answers
- Costs $100 to apply plus $150 to register, plus a separate test-site fee
Part I is meant to confirm broad technical grounding across health physics fundamentals before a candidate is allowed to attempt the far more demanding Part II. For exact numbers required to clear this bar, see CHP Passing Score 2026.
Part II: The Panel of Experts Exam
- 6-hour, closed-reference written exam
- Six mandatory core questions covering essential health physics practice
- Four additional questions selected from eight specialty problem options
- Passing requires 469 of 700 total points
- Costs $250 to apply plus $500 to register
Part II is where practical, on-the-job judgment is tested. Candidates must show they can work through realistic scenarios - dose calculations, shielding decisions, regulatory interpretation - under exam conditions, without simply recognizing a correct answer from a list.
Key Takeaway
Budget for both the application and registration fees separately at each stage, plus test-site costs for Part I - the total investment is a major planning factor covered in detail in CHP Certification Cost 2026.
| Feature | Part I | Part II |
|---|---|---|
| Format | Computer-based, Pearson VUE | Written, closed-reference |
| Length | 150 questions, 3 hours | 6 hours, 10 questions total |
| Passing Standard | ~95 correct (statistically set) | 469 of 700 points |
| Fees | $100 application + $150 registration + site fee | $250 application + $500 registration |
| 2024 Pass Rate | 30.99% | 45.83% |
For an expanded look at what these numbers mean for your odds and how they've trended, read CHP Pass Rate 2026: What the Data Shows.
The Five CHP Exam Domains
Both parts of the exam draw from the same five content domains, though the emphasis and question style differ between the multiple-choice Part I and the applied-problem Part II. Understanding domain weighting helps you allocate study time proportionally rather than spreading effort evenly across topics that don't carry equal exam weight.
Domain 1: Measurements and Instrumentation (25%)
The largest domain, covering detector theory, calibration, counting statistics, and instrument selection for different radiation types.
- Gas-filled detectors, scintillators, and semiconductor detectors
- Counting statistics and minimum detectable activity
- Calibration procedures and instrument response curves
Domain 2: Standards and Requirements (20%)
Regulatory frameworks and dose limits candidates must apply correctly in scenario-based questions.
- NRC, DOE, and EPA regulatory structures
- Occupational and public dose limits
- ALARA program requirements
Domain 3: Hazards Analysis and Controls (20%)
Identifying radiological hazards and selecting appropriate engineering or administrative controls.
- Shielding design and time-distance-shielding principles
- Contamination control and airborne hazard assessment
- Emergency response planning
Domain 4: Operations and Procedures (20%)
Applied, day-to-day health physics practice in facility settings.
- Radioactive material handling and transport
- Waste management procedures
- Facility monitoring programs
Domain 5: Fundamentals and Education (15%)
Core physics and biological effects underpinning all other domains.
- Atomic and nuclear physics fundamentals
- Radiation biology and dose-response relationships
- Basic interaction of radiation with matter
For question-by-question breakdowns and sample problem types within each domain, see the CHP Exam Domains 2026: Complete Guide to All 5 Content Areas.
Who Hires Certified Health Physicists
The CHP credential opens doors across several industries where radiation safety oversight is legally or operationally required. Common employers include:
- Commercial nuclear power plants, where a CHP often leads radiation protection programs
- Hospitals and medical centers using diagnostic or therapeutic radiation
- Federal agencies and national laboratories involved in nuclear research or defense
- Environmental consulting firms handling decommissioning and site remediation
- Academic institutions with research reactors or radioactive material licenses
Because the credential requires years of demonstrated applied experience before someone can even sit for Part II, employers treat CHP status as strong evidence of independent judgment, not just textbook knowledge. If you're weighing whether the investment pays off in your career, our analysis in Is the CHP Certification Worth It? Complete ROI Analysis 2026 and the CHP Salary Guide 2026 are worth reading before you commit. You can also browse current openings and typical role descriptions in CHP Jobs.
Eligibility for Part II
Passing Part I alone does not make someone a CHP - it's an intermediate milestone. To sit for Part II, candidates generally need:
- Six years of professional health physics experience
- At least three of those years in applied (hands-on) experience
- Qualifying formal education in health physics or a related field
- Professional references attesting to competency
- A submitted radiation protection report demonstrating independent analytical work
Candidates must complete both Part I and Part II within seven years of starting the process, which makes early planning important - waiting too long between parts can force a restart. A full eligibility checklist, including documentation tips for the radiation protection report, is available in CHP Requirements 2026: Eligibility, Prerequisites & How to Qualify.
Staying Certified: Recertification
Earning the CHP designation is not a one-time achievement. To keep using the title, certified individuals must:
- Recertify every four years
- Maintain active AAHP membership
- Accumulate 80 continuing education credits within the recertification period
This ongoing requirement keeps CHPs current with evolving regulations, new instrumentation, and updated safety practices - which is part of why the credential retains its value in the eyes of employers over the long term.
Preparing for the CHP Exam
Because Part I and Part II test different skills - recognition-based knowledge versus applied problem-solving - your preparation approach should shift between the two. For Part I, structured review of Domain 1 (Measurements and Instrumentation) deserves the most calendar time given its 25% weighting, followed by proportional attention to Domains 2 through 4. Domain 5 fundamentals are lower-weighted but often serve as the conceptual backbone for questions in the other four domains, so reviewing them early can make later material easier to absorb.
For Part II, preparation looks different: instead of memorizing facts, candidates benefit from working through realistic six-hour practice scenarios with only the references permitted in the actual exam, since the closed-reference format rewards familiarity with your own reference materials as much as raw knowledge. Practicing under a true time limit - not just answering questions casually - is one of the highest-leverage things a Part II candidate can do.
Foundations and Domain 1
- Review Domain 5 fundamentals as a base layer
- Deep dive into Measurements and Instrumentation, the highest-weighted domain
Regulatory and Hazards Domains
- Study Standards and Requirements alongside Hazards Analysis and Controls
- Practice scenario questions linking dose limits to control selection
Operations and Full Review
- Cover Operations and Procedures topics
- Run full-length timed practice exams to simulate Part I conditions
For a complete week-by-week plan and a breakdown of resources specific to each domain, see the CHP Study Guide 2026: How to Pass on Your First Attempt. You can also build exam-day comfort by working through timed practice questions on our practice test platform, which mirrors the multiple-choice format and timing of Part I.
If you need a fast-reference companion during final review, the CHP Cheat Sheet 2026: One-Page Review of Must-Know Facts condenses the highest-yield facts across all five domains onto a single page, and pairing it with regular timed drills on the practice test site tends to expose weak spots faster than passive review alone.
Frequently Asked Questions
Not exactly. Anyone working in the field may be called a health physicist, but only those who have passed both parts of the ABHP exam and maintain active status can use the CHP designation specifically.
Yes. Part I is a prerequisite, and candidates must also meet separate experience and education requirements before they're eligible to register for Part II.
Candidates must pass both Part I and Part II within seven years of beginning the certification process.
Recertification occurs every four years and requires 80 continuing education credits along with active AAHP membership; falling short can jeopardize your certified status.
Measurements and Instrumentation carries the highest weighting at 25%, making it a logical starting point, though Fundamentals and Education topics often support understanding across all other domains.
Understanding exactly what a CHP is - the credentialing body, the two-exam structure, the domains tested, and the ongoing recertification obligations - is the first real step toward earning the title yourself. From here, the practical next move is building a study plan around the specific fee structure, eligibility timeline, and domain weighting outlined above, rather than treating this as a generic professional exam.