- What CHP Actually Means
- Who Credentials the CHP and Why It Matters
- Part I and Part II: How the CHP Exam Is Built
- The Five CHP Exam Domains
- Who Qualifies to Sit for the Exam
- Who Hires Certified Health Physicists
- Mapping a Study Plan to the CHP Structure
- Staying Certified: Recertification Basics
- Frequently Asked Questions
- CHP stands for Certified Health Physicist, credentialed by the ABHP under AAHP.
- Part I has 150 questions in 3 hours; the cut score has typically been about 95 correct.
- Part II requires six core questions plus four of eight specialty problems, closed-reference, over 6 hours.
- Part II eligibility requires six years of health physics experience, including three applied years.
What CHP Actually Means
CHP stands for Certified Health Physicist, a professional credential awarded to individuals who demonstrate mastery of radiation safety, measurement, and protection practices. Unlike a college degree or a single training course, CHP status is earned through a two-part examination process administered outside any single employer or university, which is precisely why it carries weight across government agencies, national laboratories, hospitals, and private industry alike.
If you found this page while searching for a plain-language explanation, you may also want a companion piece that expands on the acronym itself, such as CHP Meaning or What Does CHP Stand For?. This article goes further by explaining the exam mechanics, domains, and career context behind the letters.
For readers who want the certification framed as a professional milestone rather than just a definition, What Is A CHP? and What Is CHP Certification? cover related angles worth reading alongside this guide.
Who Credentials the CHP and Why It Matters
The CHP credential is issued by the American Board of Health Physics (ABHP), which operates within the American Academy of Health Physics (AAHP). This structure matters because it separates the certifying board from any single employer, training vendor, or academic program. The ABHP sets the exam content, scoring standards, and eligibility rules, and it is the body that ultimately decides whether a candidate has demonstrated competence sufficient to practice independently as a health physicist.
This independence is also why the exam is deliberately rigorous rather than a formality. It is not a course completion certificate; it is a licensure-style evaluation built to filter for genuine command of health physics principles.
Part I and Part II: How the CHP Exam Is Built
The path to becoming a Certified Health Physicist runs through two distinct exams, each with its own format, cost, and purpose.
Part I: The Foundational Screening Exam
Part I is delivered as a computer-based test at Pearson VUE testing centers. It consists of 150 five-option multiple-choice questions completed within a 3-hour window. The cut score is set statistically rather than fixed at a round number, but it has typically landed around 95 correct answers. Registering for Part I involves a $100 application fee plus a $150 registration fee, and candidates also pay a separate test-site fee directly to the testing vendor.
Part II: The Applied Practice Exam
Part II is a different animal entirely. It is a 6-hour, closed-reference exam that requires candidates to respond to six core questions plus four of eight specialty problems, allowing some choice in which specialty areas to tackle. Scoring is out of 700 points, and passing requires 469 points**. Part II costs **$250 to apply and **$500 to register, reflecting its more resource-intensive administration and grading process.
Key Takeaway
Part I tests breadth across foundational knowledge under multiple-choice conditions, while Part II tests depth and applied judgment through long-form technical problems - treat them as two separate study campaigns, not one continuous effort.
Candidates must pass both parts within seven years of starting the process, so pacing matters. For a deeper dive into exactly how the scoring thresholds work, see CHP Passing Score 2026: Exactly What You Need to Pass, and for a full fee breakdown including site costs, see CHP Certification Cost 2026: Complete Pricing Breakdown.
| Feature | Part I | Part II |
|---|---|---|
| Format | 150 multiple-choice questions | 6 core + 4 of 8 specialty questions |
| Duration | 3 hours | 6 hours |
| Delivery | Computer-based (Pearson VUE) | Closed-reference written exam |
| Passing Standard | ~95 correct (statistically set) | 469 of 700 points |
| Fees | $100 application + $150 registration | $250 application + $500 registration |
| 2024 Pass Rate | 30.99% | 45.83% |
For more context on what these figures mean for your odds of success, CHP Pass Rate 2026: What the Data Shows breaks down the numbers in detail, and How Hard Is the CHP Exam? Complete Difficulty Guide 2026 discusses the difficulty from a candidate's perspective.
The Five CHP Exam Domains
Both exam parts draw content from five weighted domains. Understanding these domains - and their relative weight - is the single most useful thing a candidate can do before opening a single practice question.
Domain 1: Measurements and Instrumentation (25%)
The largest domain by weight, covering detector theory, calibration, counting statistics, and instrument selection for different radiation types.
- Gas-filled detectors, scintillation counters, and semiconductor detectors
- Efficiency, dead time, and minimum detectable activity calculations
- Instrument selection logic for alpha, beta, gamma, and neutron fields
Domain 2: Standards and Requirements (20%)
Covers regulatory frameworks, dose limits, and the standards bodies that govern health physics practice.
- NRC and DOE regulatory structures
- ALARA principles and occupational dose limits
- Reporting and licensing requirements
Domain 3: Hazards Analysis and Controls (20%)
Focuses on identifying radiation hazards and selecting appropriate engineering and administrative controls.
- Shielding design and dose-rate reduction strategies
- Contamination control and internal dosimetry
- Emergency response planning for radiological incidents
Domain 4: Operations and Procedures (20%)
Tests practical, on-the-job scenarios: survey execution, waste handling, and procedural compliance.
- Radiation survey techniques and documentation
- Radioactive waste classification and disposal procedures
- Facility operational safety protocols
Domain 5: Fundamentals and Education (15%)
The smallest domain, but foundational - covering atomic and nuclear physics, decay processes, and interaction of radiation with matter.
- Radioactive decay modes and half-life calculations
- Radiation interaction mechanisms with matter
- Basic dosimetry and biological effects fundamentals
Because Domain 1 alone carries a quarter of the exam's weight, candidates who under-invest in instrumentation topics often find their overall score suffers disproportionately. A full walkthrough of each domain's subtopics, along with sample question styles, is available in CHP Exam Domains 2026: Complete Guide to All 5 Content Areas.
Who Qualifies to Sit for the Exam
Part I has comparatively open eligibility and functions as the entry screening step. Part II is where the ABHP tightens requirements considerably. To sit for Part II, candidates generally need six years of professional health physics experience, of which three years must be applied experience directly working in the field rather than purely academic or research settings. Beyond the experience requirement, candidates must also submit qualifying education documentation, professional references, and a radiation protection report demonstrating applied competence.
Because these requirements are detailed and occasionally misunderstood, we've built a dedicated resource covering every eligibility nuance: CHP Requirements 2026: Eligibility, Prerequisites & How to Qualify. It's worth reading before you assume you're ready to register.
Who Hires Certified Health Physicists
The CHP credential signals a specific, verifiable level of competence, which is why it appears as a preferred or required qualification across several industries:
- Nuclear power utilities - radiation safety officers and health physics supervisors overseeing plant operations
- National laboratories and government agencies - research safety oversight and regulatory compliance roles
- Hospitals and medical centers - radiation safety programs for diagnostic and therapeutic radiation sources
- Environmental and consulting firms - decommissioning, decontamination, and radiological risk assessment
- Defense and federal contractors - radiological protection for weapons and materials programs
For a closer look at compensation trends across these settings, see CHP Salary Guide 2026: Complete Earnings Analysis, and for a broader assessment of whether pursuing the credential pays off given the time and cost involved, Is the CHP Certification Worth It? Complete ROI Analysis 2026 weighs the tradeoffs directly. If you're specifically hunting for open roles, CHP Jobs covers where positions tend to be posted and what employers look for.
Mapping a Study Plan to the CHP Structure
Generic study advice rarely accounts for the fact that CHP Part I and Part II reward different skills. Part I favors quick recall and calculation speed across a wide breadth of topics; Part II rewards depth, written technical reasoning, and the ability to work without reference materials for extended stretches.
Domain 1 and Domain 5 Fundamentals
- Build core physics and instrumentation fluency before layering on regulatory detail
- Practice detector efficiency and decay calculations until they're automatic
Domain 2 and Domain 3
- Study regulatory limits and standards alongside hazard control scenarios, since they frequently overlap in question stems
- Work through shielding and dose-rate problems under timed conditions
Domain 4 and Full Timed Practice
- Focus on operational procedures and survey documentation scenarios
- Run full-length timed practice sessions mimicking the 3-hour Part I format
Because Part II is closed-reference, candidates preparing for it should shift strategy entirely toward memorizing formulas and working practice problems by hand, rather than relying on lookup speed. A structured week-by-week plan covering both exam parts, including how to pace toward the seven-year window, is laid out fully in CHP Study Guide 2026: How to Pass on Your First Attempt. For a condensed reference you can review in the final days before test day, CHP Cheat Sheet 2026: One-Page Review of Must-Know Facts consolidates the highest-yield facts in one place.
Running realistic practice sessions on our practice test platform before test day is one of the most direct ways to gauge readiness against the actual five-domain weighting, since generic radiation-science review materials rarely mirror the ABHP's specific question style.
Staying Certified: Recertification Basics
Passing both exam parts is not the end of the obligation. CHPs must recertify every four years, which requires maintaining active AAHP membership and accumulating 80 continuing education credits during that period. This keeps certified professionals current as regulations, instrumentation, and industry practices evolve.
If you're still deciding whether the credential itself is the right fit for your career trajectory, reviewing the general overview at CHP Certification or the training pathways discussed in CHP Training can help clarify next steps before you commit to the exam timeline. And if you landed here simply looking for a quick definition, What Does CHP Mean? offers the short version, while this page and What Is CHP? go deeper into the mechanics.
Frequently Asked Questions
It is a professional certification issued by the American Board of Health Physics, not a state-issued license, though many employers treat it as a de facto requirement for senior health physics roles.
No. Part I functions as the foundational screening exam, and candidates progress toward Part II only after meeting its requirements, alongside the six years of experience needed for Part II eligibility.
Candidates must pass both Part I and Part II within seven years of beginning the certification process.
Domain 1, Measurements and Instrumentation, carries the highest weight at 25%, making it the single most important content area to master thoroughly.
Yes. Recertification is required every four years and involves maintaining active AAHP membership plus earning 80 continuing education credits.