- Part I is 150 questions in 3 hours with a cut score historically near 95 correct.
- Part II demands six core questions plus four of eight specialty problems in 6 hours, closed-reference, 469/700 to pass.
- Domain weighting favors Measurements and Instrumentation (25%) and two 20% domains: Standards and Requirements, Hazards Analysis and Controls.
- Part II eligibility needs six years of health physics experience, three of them applied, plus a radiation protection report.
Exam Snapshot: Part I and Part II at a Glance
This is the condensed, one-page version of what you need memorized before walking into either exam administered under the American Board of Health Physics (ABHP), part of the American Academy of Health Physics (AAHP). If you need the full narrative version with context and reasoning, read the complete CHP Study Guide 2026 - but this page is built for quick review sessions and last-minute checks.
| Feature | Part I | Part II |
|---|---|---|
| Format | 150 five-option multiple-choice questions, Pearson VUE computer-based | 6-hour closed-reference exam: 6 core questions + 4 of 8 specialty problems |
| Time Limit | 3 hours | 6 hours |
| Passing Standard | Statistically set cut score, historically about 95 correct | 469 of 700 points |
| Application Fee | $100 | $250 |
| Registration Fee | $150 (plus separate test-site fee) | $500 |
| 2024 Pass Rate | 30.99% | 45.83% |
Notice that Part II's pass rate was higher than Part I's in 2024 - a pattern worth understanding rather than dismissing. For a deeper breakdown of why, see the CHP Pass Rate 2026 analysis and the companion piece on How Hard Is the CHP Exam?.
The Five Domains Distilled
Every Part I question maps to one of five domains. Weight your review time proportionally, not equally. The CHP Exam Domains 2026 Complete Guide covers each area in depth; here is the compressed version for rapid recall.
Domain 1: Measurements and Instrumentation (25%)
The single heaviest domain. Candidates must be fluent in detector physics and applied counting statistics.
- Gas-filled detectors (ionization chambers, proportional counters, GM tubes) and their operating regions
- Scintillation and semiconductor detector response, efficiency, and energy resolution
- Counting statistics: minimum detectable activity, propagation of uncertainty, dead time corrections
- Calibration principles and instrument response to different radiation types
Domain 2: Standards and Requirements (20%)
Regulatory literacy is tested through applied scenarios, not rote citation lookup.
- 10 CFR Parts 20, 30, 34, 61, 71, and related NRC/DOE frameworks
- ALARA program requirements and dose limit tables for occupational and public exposure
- Licensing conditions, reporting thresholds, and recordkeeping obligations
Domain 3: Hazards Analysis and Controls (20%)
This domain blends internal and external dosimetry with practical shielding and contamination-control decisions.
- Internal dose assessment, intake modeling, and committed effective dose calculations
- Shielding design for gamma, beta, neutron, and mixed-field sources
- Contamination control, surface activity limits, and respiratory protection selection
Domain 4: Operations and Procedures (20%)
Field-level judgment questions dominate this domain - expect scenario-based items about real facility operations.
- Emergency response actions and notification sequences
- Radioactive material transportation and packaging classification
- Survey planning, source control, and decommissioning procedures
Domain 5: Fundamentals and Education (15%)
The smallest domain but the foundation everything else rests on.
- Atomic and nuclear structure, decay modes, and interaction of radiation with matter
- Risk communication and training program principles
- Basic biological effects of ionizing radiation
Part I Must-Knows
Part I is a five-option multiple-choice exam delivered through Pearson VUE testing centers. There is no partial credit and no penalty for guessing, so every question deserves an answer before time expires. With 150 questions in 180 minutes, that is 72 seconds per question on average - tight enough that calculation-heavy items from Domain 1 need memorized formulas, not derivations from scratch.
- Cut score mechanics: The passing threshold is statistically derived each cycle, but it has typically landed near 95 correct answers out of 150.
- Application vs. registration: The $100 application fee and $150 registration fee are billed separately, and a test-site fee applies on top - budget for three line items, not one. See the full CHP Certification Cost 2026 breakdown.
- Question style: Expect a mix of direct recall (regulatory limits, detector types) and applied calculation (shielding attenuation, dose rate conversions, statistical uncertainty).
- No open references: Part I is closed-book. Formula recall must be automatic, not looked up.
Key Takeaway
Treat the roughly 95-correct benchmark as your working target throughout practice testing - if you consistently clear it with margin on timed practice sets, you are exam-ready for Part I.
Part II Must-Knows
Part II is a fundamentally different animal: a 6-hour, closed-reference written exam requiring detailed, multi-step problem solving rather than single best-answer selection.
- Structure: Six core questions are mandatory for everyone, plus four selections from eight specialty problems - choose your specialty problems based on your actual work background.
- Scoring: 469 of 700 total points is required to pass. Partial credit exists, so showing complete work matters more than on Part I. Full mechanics are covered in the CHP Passing Score 2026 guide.
- Eligibility gate: You need six years of professional health physics experience, including three years of applied experience, plus qualifying education, references, and a submitted radiation protection report before you can even sit for Part II. Details live in the CHP Requirements 2026 article.
- Fees: $250 to apply and $500 to register - five times the cost of Part I's registration fee, reflecting the exam's depth and the review burden on graders.
Fees, Eligibility, and the Seven-Year Clock
Money and timing catch candidates off guard more often than content does. Here is the compressed fee and timeline picture:
| Item | Cost or Requirement |
|---|---|
| Part I application | $100 |
| Part I registration | $150 + separate test-site fee |
| Part II application | $250 |
| Part II registration | $500 |
| Experience requirement | 6 years professional HP experience, 3 years applied |
| Time limit between parts | Both parts must be passed within 7 years of each other |
The seven-year rule is unforgiving: if you pass Part I early in your career but delay Part II eligibility documentation, the clock keeps running. Map your experience-accrual timeline against exam scheduling using the CHP Exam Dates 2026 guide so you are not racing the deadline in year six.
Key Takeaway
Start assembling your radiation protection report and professional references for Part II well before you technically hit the six-year experience mark - documentation review takes time you don't want to lose against the seven-year window.
Final-Week Review Sequence
Generic study frameworks rarely map cleanly onto a two-part credentialing exam like this, but a short, CHP-specific final push works well in the days before test day. This is not a full study plan - see the CHP Study Guide 2026 for that - but a compressed cheat-sheet sequence for the last stretch.
Domain 1 Refresh
- Re-derive minimum detectable activity and dead-time formulas from memory
- Drill detector response scenarios (gas-filled vs. scintillation vs. semiconductor)
Domains 2 and 3
- Cycle through dose limit tables and shielding attenuation problems
- Practice internal dose intake scenarios timed at Part I pace
Domain 4 Scenarios
- Work through emergency response and transportation classification vignettes
- Review procedural sequencing questions, since these often hinge on ordering steps correctly
Fundamentals and Full Simulation
- Quick pass on Domain 5 fundamentals to lock in decay and interaction basics
- Take one full timed 150-question practice run to confirm pacing against the roughly 95-correct benchmark
Run your final full-length simulation on our practice test platform so the pacing and five-option format feel automatic before you sit for the real Pearson VUE session.
Recertification in Brief
Passing both parts is not the finish line. The credential requires recertification every four years, contingent on maintaining active AAHP membership and accumulating 80 continuing education credits. Build a lightweight tracking habit now - logging conference hours, technical courses, and relevant training the moment you earn credits - rather than scrambling near your renewal deadline.
If you are still weighing whether the entire process is worth the investment of time, fees, and continuing education commitment, the Is the CHP Certification Worth It? Complete ROI Analysis 2026 article and the CHP Salary Guide 2026 lay out the career-side calculus in detail.
Frequently Asked Questions
Part I covers five weighted domains - Measurements and Instrumentation, Standards and Requirements, Hazards Analysis and Controls, Operations and Procedures, and Fundamentals and Education - through 150 multiple-choice questions. Part II tests the same knowledge base at greater depth through six core questions and four chosen specialty problems.
The cut score is statistically set each administration, but it has typically been around 95 correct out of 150 questions.
Part I is closed-book with no references. Part II is a closed-reference exam as well, though its 6-hour format and partial-credit scoring reward thorough shown work more than Part I does.
Both parts must be passed within seven years of each other, so plan your Part II eligibility documentation - including experience hours and your radiation protection report - well before that window closes.
You recertify every four years by maintaining active AAHP membership and earning 80 continuing education credits during that period.
For quick terminology refreshers, the site's glossary-style pages on What Is CHP?, CHP Meaning, and What Is CHP Certification? are useful companions to this cheat sheet, and pairing this page with timed practice on our full practice exam simulator is the fastest way to confirm you've internalized every fact above.