- CHP is credentialed by the ABHP within AAHP, not a general safety board.
- Part I is 150 questions in 3 hours; cut score has typically run about 95 correct.
- Part II demands six core questions plus four of eight specialty problems across 6 hours.
- Part II eligibility needs six years of experience, including three years applied, plus a radiation protection report.
What CHP Certification Actually Is
The Certified Health Physicist (CHP) credential is issued by the American Board of Health Physics (ABHP), operating under the American Academy of Health Physics (AAHP). It is the recognized professional certification for practitioners who assess and control radiation hazards in medical, nuclear, industrial, academic, and government settings. Unlike broad safety certifications, CHP is narrowly built around applied health physics practice: dose assessment, shielding calculations, instrumentation calibration, and regulatory compliance under bodies like the NRC and DOE.
If you're still mapping out what the letters mean or how the credential fits into a career trajectory, the primer articles What Is CHP? and CHP Meaning cover the basics before you dive into exam mechanics. For a strict definition of the abbreviation itself, see What Does CHP Stand For?.
The Two-Part Exam Structure
CHP certification is earned through two distinct, sequential exams rather than a single test. This structure separates foundational knowledge from applied professional judgment.
Part I: The Screening Exam
Part I is delivered as a computer-based exam through Pearson VUE. It consists of 150 five-option multiple-choice questions administered in 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. This exam checks whether a candidate has the fundamental technical grounding - radiation physics, dosimetry principles, statistics, and instrument theory - needed before being trusted with Part II's applied scenarios.
Part II: The Applied Exam
Part II is a 6-hour, closed-reference written exam. Candidates must answer six core questions that everyone completes, plus four of eight specialty problems chosen from an elective pool covering different practice areas. Scoring is out of 700 total points, and passing requires 469 points. This format rewards candidates who can reason through multi-step, real-world radiation protection problems rather than recall isolated facts.
Because the two exams test different skills, preparation strategy differs sharply between them - a distinction covered in depth in How Hard Is the CHP Exam? Complete Difficulty Guide 2026.
The Five Exam Domains
Part I content is organized into five domains, each weighted differently. Understanding these weights should directly shape how you allocate study time - spending equal time on all five domains is a common and costly mistake.
Domain 1: Measurements and Instrumentation (25%)
The single largest domain, covering detector theory, counting statistics, calibration, and interpretation of instrument response.
- Gas-filled detectors, scintillators, and semiconductor detectors
- Efficiency, minimum detectable activity, and counting error propagation
- Calibration sources and geometry corrections
Domain 2: Standards and Requirements (20%)
Regulatory knowledge tied to NRC, DOE, EPA, and consensus standards such as those from the NCRP and ICRP.
- Dose limits for occupational and public exposure
- Licensing, reporting thresholds, and recordkeeping obligations
- ALARA program requirements
Domain 3: Hazards Analysis and Controls (20%)
Practical hazard evaluation and the engineering or administrative controls used to mitigate exposure.
- Shielding design calculations for gamma, beta, and neutron sources
- Contamination control and internal dose assessment
- Emergency planning and criticality safety basics
Domain 4: Operations and Procedures (20%)
Day-to-day health physics program management in the field.
- Survey techniques and respiratory protection
- Source handling, transport, and waste management procedures
- Personnel dosimetry program operation
Domain 5: Fundamentals and Education (15%)
Core physics and biological effects that underpin every other domain.
- Atomic and nuclear structure, decay schemes
- Interaction of radiation with matter
- Biological effects and risk models
A full breakdown of subtopics, sample question phrasing, and domain-by-domain study sequencing is available in CHP Exam Domains 2026: Complete Guide to All 5 Content Areas.
Eligibility and the Path to Part II
Passing Part I alone does not confer certification, and it does not automatically qualify you for Part II. Part II eligibility is built around demonstrated professional practice, not just exam readiness.
- Six years of professional health physics experience, of which three years must be applied, hands-on experience.
- Qualifying education in health physics or a closely related science or engineering discipline.
- Professional references attesting to your practice and judgment.
- A radiation protection report documenting real work you performed, submitted for review as part of the application.
Candidates must complete both parts within a seven-year window, which makes sequencing your Part I attempt carefully important - failing Part I multiple times eats into the clock for building Part II experience and eligibility documentation. The full checklist of documentation, timelines, and qualifying experience categories is detailed in CHP Requirements 2026: Eligibility, Prerequisites & How to Qualify.
Key Takeaway
Start assembling your radiation protection report and references well before you sit for Part I - the seven-year clock starts running early, and documentation gaps are a common cause of delayed Part II applications.
Fees, Registration, and Timelines
CHP certification carries meaningful cost at each stage, and the fee structure is split between application and registration for both parts.
| Item | Application Fee | Registration Fee | Format |
|---|---|---|---|
| Part I | $100 | $150 (plus separate test-site fee) | 150 MCQs, 3 hours, Pearson VUE |
| Part II | $250 | $500 | 6-hour closed-reference, 6 core + 4 of 8 specialty questions |
Note that Part I also involves a separate test-site fee charged by Pearson VUE beyond the ABHP application and registration amounts. Because these costs stack across both parts - plus potential retake fees if you don't pass on the first try - it's worth budgeting the full multi-year path rather than just the next exam date. A complete cost breakdown, including retake scenarios, is in CHP Certification Cost 2026: Complete Pricing Breakdown.
Registration windows and deadlines matter too, since missing an application cycle can push your attempt back significantly. Current testing windows are tracked in CHP Exam Dates 2026: Testing Windows, Deadlines & Scheduling.
Who Hires Certified Health Physicists
CHP holders are employed across a fairly narrow but stable set of sectors where ionizing radiation is present and regulated:
- Nuclear power utilities needing radiation protection managers and ALARA program leads.
- Federal agencies and national laboratories, including DOE sites and NRC-adjacent contractors.
- Hospitals and academic medical centers running radiation oncology, nuclear medicine, or diagnostic imaging programs.
- Consulting and engineering firms supporting decommissioning, waste management, and licensing work.
- Industrial radiography and manufacturing operations using sealed sources or accelerators.
Employers in these sectors often list CHP as a preferred or required credential for senior radiation safety officer and health physicist roles, since it signals both the fundamentals tested in Part I and the applied judgment verified in Part II. For a sense of what these roles pay and how certification affects compensation, see CHP Salary Guide 2026: Complete Earnings Analysis, and for open-role patterns, browse CHP Jobs.
Whether the time and cost investment translates into a real career return is a fair question to ask before committing to the seven-year certification window - it's addressed directly in Is the CHP Certification Worth It? Complete ROI Analysis 2026.
Building a CHP-Specific Study Plan
Generic exam-prep methods - spaced repetition, timed practice blocks, active recall - work fine as scaffolding, but they only pay off when applied against CHP's actual weighting and question style. Since Domain 1 (Measurements and Instrumentation) carries the heaviest weight at 25%, it deserves the earliest and most repeated review cycles, not an equal 20% slice of your calendar.
Domain 1 and Domain 5 Foundations
- Detector theory, counting statistics, and calibration math
- Nuclear structure and radiation interaction fundamentals that underpin later domains
Domain 2 and Domain 3
- Dose limits, licensing, and ALARA regulatory detail
- Shielding calculations and hazard control scenarios
Domain 4 and Timed Practice
- Operational procedures: surveys, dosimetry programs, waste handling
- Full 150-question timed simulations under 3-hour conditions
Part II preparation looks different: instead of covering all content evenly, focus on the six core question types and pick your four specialty areas based on your actual work experience, since Part II rewards depth over breadth. A worksheet-style walkthrough of this exact sequencing, along with practice problems by domain, is in CHP Study Guide 2026: How to Pass on Your First Attempt. If you want a fast-reference summary for final review days, CHP Cheat Sheet 2026: One-Page Review of Must-Know Facts condenses the highest-yield facts into one page.
Recertification and Maintaining CHP Status
Earning CHP status is not a one-time event. Certified Health Physicists must recertify every four years, which requires two things concurrently: active membership in AAHP and accumulation of 80 continuing education credits over the recertification cycle. This structure keeps certified professionals current with evolving regulations and technology rather than resting on a credential earned years earlier.
Continuing education can typically come from conferences, coursework, published work, and professional training programs - planning these credits early in the four-year cycle avoids a last-minute scramble. If you're weighing formal coursework options to both prepare for initial certification and build a habit of ongoing education, CHP Training outlines available formats.
Frequently Asked Questions
Part I uses a statistically set cut score rather than a fixed percentage, but it has typically required about 95 correct answers out of 150 questions. For a deeper explanation of how this score is calculated, see CHP Passing Score 2026: Exactly What You Need to Pass.
No. Part I must be passed first, and Part II eligibility additionally requires six years of professional health physics experience, including three years of applied experience, along with qualifying education, references, and a submitted radiation protection report.
Both parts are considered rigorous: Part I in 2024 had a 30.99% pass rate, and Part II had a 45.83% pass rate. A full statistical breakdown is available in CHP Pass Rate 2026: What the Data Shows.
Part I costs $100 to apply plus $150 to register, with an additional Pearson VUE test-site fee. Part II costs $250 to apply plus $500 to register. See CHP Certification Cost 2026: Complete Pricing Breakdown for the full multi-year cost picture.
Candidates have a seven-year window from their first attempt to pass both Part I and Part II. Missing this window generally means restarting the application and testing process, so sequencing your attempts and experience documentation carefully matters from day one.