- What You Are Actually Studying For
- Exam Mechanics: Format, Fees, and Eligibility
- The 14 Preparation Categories, Grouped by How You Study Them
- Domains 3 Through 9: The Compliance Block
- Domains 10 Through 14: The Coding Block
- Using Your Code Books on Exam Day
- Sequencing Your Preparation Around the Domains
- Choosing Resources and Practice Material
- After You Pass: Maintenance and Where the Credential Fits
- Frequently Asked Questions
- CHONC is AAPC's Certified Hematology and Oncology Coder exam: 100 multiple-choice questions, four hours, 70 correct to pass.
- AAPC publishes 14 competency areas, not a weighted blueprint, so the largest domain is unknown. Study all 14.
- Active AAPC membership is required to sit the exam; CPC or COC is not a prerequisite.
- Approved CPT, ICD-10-CM and HCPCS Level II books are allowed, but the AAPC study guide is not.
What You Are Actually Studying For
The Certified Hematology and Oncology Coder credential is issued by AAPC and tests whether you can code hematology and oncology encounters accurately from physician and operative documentation. If you are new to the credential, the explainers on what CHONC certification is and what CHONC stands for cover the basics. This guide assumes you have decided to sit for it and want a plan.
The first thing to understand is how AAPC describes the exam's content. The 2026 official materials list 14 competency areas, but they do not publish a numbered, weighted blueprint. That means nobody outside the exam development process can tell you which area carries the most questions. Any guide that claims a precise percentage for, say, E/M selection versus modifier usage is guessing. Your safest strategy is balanced coverage of all 14, with extra time on the areas where your own work history is thinnest.
The second thing to understand is the tone of AAPC's own sample material. The 2026 study guide sample states that the guide is not comprehensive and that hands-on specialty coding experience matters. It also describes assessment based on operative and physician notes. In practice, that tells you the exam will not reward memorized trivia alone. It rewards the ability to read documentation and make correct coding decisions.
Exam Mechanics: Format, Fees, and Eligibility
Knowing the logistics removes avoidable stress. Here is what the current official guidance supports:
| Item | What applies to CHONC |
|---|---|
| Issuer | AAPC |
| Format | 100 multiple-choice questions |
| Time limit | 4 hours, in one sitting |
| Passing standard | 70 correct answers (70%) |
| Delivery | Meazure Learning test centers or ProctorU by Meazure Learning remote proctoring |
| Exam fee | USD 325 for one attempt; USD 399 for two attempts |
| Membership | Active AAPC membership required; no non-member exam-only tier. Observed membership add-on: USD 229 |
| Prerequisites | CPC or COC not required; specialty experience recommended; no mandatory degree verified |
Two details deserve attention. First, AAPC does not disclose how many of the 100 questions are scored versus unscored, so treat every question as if it counts. Second, the CHONC-specific pass rate is not publicly disclosed. For the full picture on what is and is not known, see our breakdown of the CHONC pass rate and the CHONC passing score.
Budget realistically. The exam fee is only part of the cost, because membership is mandatory and study materials come on top. Our CHONC certification cost breakdown walks through the full total, and the CHONC requirements guide covers eligibility in detail.
The 14 Preparation Categories, Grouped by How You Study Them
The 14 preparation categories are the top-level competency bullets in the 2026 AAPC CHONC Study Guide sample. They are published exam-related competencies, not official weighted domains, and not a verified exhaustive list of exam coverage. Still, they are the best map available. The most efficient way to use them is to group them by the kind of thinking each requires.
| Group | Domains | How you study it |
|---|---|---|
| Foundations | 1 Medical terminology and anatomy; 2 Medical physiology | Vocabulary and concept building tied to hematologic and oncologic disease |
| Compliance and billing rules | 3 Teaching physician guidelines; 4 Incident-to guidelines; 5 Split/Shared services; 6 HIPAA regulations; 7 Proper use of the ABN; 8 CMS drug wastage policy; 9 Clinical trial services | Rule recall and scenario application |
| Code selection | 10 ICD-10-CM coding; 11 E/M code selection using the AMA CPT E/M guidelines; 12 CPT coding for common procedures; 13 CPT and HCPCS Level II modifier usage; 14 HCPCS Level II coding | Hands-on practice with code books and documentation |
For a deeper domain-by-domain treatment, the CHONC exam domains guide expands on all 14 content areas.
Domains 1 and 2: Medical Terminology, Anatomy, and Physiology
These are foundation areas, but in a hematology and oncology context they are not trivial. You need to decode terms from operative and physician notes quickly, because misreading a term leads to a wrong code downstream.
- Be comfortable with blood-related and cancer-related terminology you will see in encounter documentation.
- Understand how blood cells, the lymphatic system and organ systems relate to the conditions you code.
- Connect physiology to coding: knowing why a procedure or lab is performed helps you choose the right code.
Domains 3 Through 9: The Compliance Block
This block is where many coders with strong code-lookup skills lose points, because the questions turn on policy rules rather than on finding a code. Seven of the 14 areas live here, so do not treat it as an afterthought.
Teaching Physician, Incident-To, and Split/Shared Services (Domains 3, 4, 5)
These three areas all answer a version of the same question: who performed the service, and who can bill for it? Oncology practices commonly involve physicians, residents, nurse practitioners and physician assistants, so these rules matter in daily work.
- Learn the documentation conditions that must be met for each arrangement, and practice telling the three apart.
- Pay attention to what changes the billing provider in each scenario.
- Apply current official guidance, and remember that payer-specific assumptions apply only when a question states them.
HIPAA, ABN, and Drug Wastage (Domains 6, 7, 8)
Oncology involves expensive drugs and sensitive records, which makes these topics especially relevant.
- HIPAA: know the privacy and security principles as they apply to coding and billing staff.
- ABN: understand when an Advance Beneficiary Notice is proper to use and what it communicates to the patient.
- CMS drug wastage policy: understand how discarded drug amounts from single-dose containers are handled and documented, since infusion and injection drugs are central to this specialty.
Clinical Trial Services (Domain 9)
Clinical trials are a distinctive feature of oncology care. Expect questions on how services delivered to trial participants are handled for coding and billing, including distinguishing routine care from services tied to the study. Review this area deliberately, because it is less familiar to coders who have only worked in general practice settings.
Domains 10 Through 14: The Coding Block
This is the hands-on portion, and it is where specialty experience pays off most.
ICD-10-CM Coding (Domain 10)
Expect diagnosis coding for malignancies and blood disorders from documentation. Focus on guideline-driven decisions: how to sequence a primary malignancy versus a secondary site, how to handle encounters directed at treatment versus surveillance, and how to read documentation to find the most specific supported code. The sample's table of contents lists additional published diagnostic detail, so confirm the specific conditions in the paid guide you use.
E/M Code Selection (Domain 11)
The exam names the AMA CPT E/M guidelines specifically. Practice selecting a level based on medical decision making or time, and get fluent with what each element requires. Note that exam rules distinguish the provided online E/M calculator from a prohibited personal calculator, so learn the tool you will be given rather than relying on your own.
CPT Coding for Common Procedures (Domain 12)
AAPC publishes five subtopics under this competency. Treat them as a checklist:
- 30000 Series
- Laboratory and Pathology
- Radiology
- Medicine
- Category III codes
Laboratory and pathology, radiology and medicine sections all matter in a specialty where diagnostics and therapeutic administration are routine. Do not skip Category III codes just because they are emerging-technology placeholders; they are explicitly listed.
Modifiers and HCPCS Level II (Domains 13 and 14)
Modifier usage spans both CPT and HCPCS Level II, so study them together. Know when a modifier is needed to explain a circumstance, and be able to reason about the correct one from a scenario. For HCPCS Level II, build comfort navigating the code set efficiently, because drug and supply coding is a major part of oncology billing.
Using Your Code Books on Exam Day
The exam is open-book in a limited sense. Approved CPT Professional, ICD-10-CM and HCPCS Level II references are allowed under current print and electronic rules. The AAPC study guide itself is not allowed. Live proctoring and equipment requirements apply, especially for remote delivery, and you must present valid ID along with your membership and examination authorization.
With four hours for 100 questions you have time, but not unlimited time. Practice a pace that leaves room to review flagged questions. See the CHONC difficulty guide for a realistic look at where candidates struggle.
Sequencing Your Preparation Around the Domains
Because there is no official weighting, a domain-ordered plan beats a time-ordered one. Here is one sequence built around the dependency between topics. Adjust the length to your experience and your exam date; the CHONC exam dates guide explains scheduling.
Foundations (Domains 1 and 2)
- Build hematology and oncology vocabulary from real documentation.
- Tie physiology to the procedures and diagnoses you will code later.
Rules of billing (Domains 3 through 9)
- Study teaching physician, incident-to and split/shared together to compare them.
- Cover HIPAA, ABN, drug wastage and clinical trials with scenario questions.
Diagnosis and E/M (Domains 10 and 11)
- Code from sample notes using ICD-10-CM guidelines.
- Practice E/M leveling with the provided calculator approach.
Procedures, modifiers, HCPCS (Domains 12 through 14)
- Work through all five CPT subtopics, including Category III.
- Pair modifier practice with the procedures they attach to.
Full-length simulation
- Take timed, mixed-domain sets using your actual approved books.
- Review misses by domain and revisit your weakest groups.
This is the only generic-methodology section you need: sequence by dependency, mix domains in the final phase, and review errors by domain. Everything else in your preparation should be specific to the 14 areas above.
Choosing Resources and Practice Material
AAPC offers a CHONC study guide, and the publicly available sample shows its structure. Remember what the sample itself says: it is not comprehensive, and it is not the full paid guide. Use it as a starting skeleton, not a guarantee of coverage.
When evaluating any practice question, ask whether it reflects current official ICD-10-CM, CPT, HCPCS and regulatory guidance, and whether it states payer assumptions explicitly. A question that depends on an unstated payer rule is a poor model of what you will face. Our CHONC cheat sheet is a good quick-review companion, and you can pressure-test your knowledge with timed sets on the CHONC practice test site. Mixed-domain practice there is useful in the final phase of your plan.
Key Takeaway
Use your wrong answers as your map. Because the exam has no published weights, your own error pattern across the 14 domains is the most reliable guide to where to spend your remaining study time.
After You Pass: Maintenance and Where the Credential Fits
Earning CHONC is not a one-time event. To keep it, you maintain annual AAPC membership and complete 36 CEUs per two-year cycle for a single credential, including eight hematology/oncology CEUs. Totals differ if you hold multiple credentials, so check your own situation.
On the career side, this credential suits coders working with oncology and hematology practices, infusion services and related billing operations. See CHONC jobs for the kinds of roles where it applies. On pay, there is no verified 2026 CHONC salary premium, so be skeptical of any specific figure; the CHONC salary guide and the worth-it analysis discuss how to weigh the investment honestly. If you are still evaluating, the CHONC certification overview and the CHONC training page are good places to continue. Ready to test yourself? Start with the free questions on the main practice site.
Frequently Asked Questions
The CHONC exam has 100 multiple-choice questions with a four-hour limit in one sitting. You pass with 70 correct answers, which is 70 percent. AAPC does not disclose how many questions are scored versus unscored.
No. CPC and COC are not prerequisites. You do need an active AAPC membership, valid ID and examination authorization. Specialty experience is recommended, though no mandatory degree or training-hour total has been verified.
That is unknown. AAPC publishes 14 competency areas but not a weighted blueprint, so the largest domain cannot be identified. The safest approach is to prepare across all 14 and focus extra time on your weakest areas.
Approved CPT Professional, ICD-10-CM and HCPCS Level II references are allowed under current print and electronic rules. The AAPC study guide is not allowed, and a personal calculator is prohibited, though an online E/M calculator is provided.
The specialty exam is USD 325 for one attempt or USD 399 for two attempts, and active AAPC membership is required, with an observed membership add-on of USD 229. Study materials are additional.