- Why "ACHRN Exam Domains" Isn't Really a Thing
- The CHRN Exam You Must Pass First
- The Four Contribution Categories That Replace Domains
- Experience Hours and Continuing Education Requirements
- Fees and the Four-Year Renewal Cycle
- Who Actually Pursues ACHRN Advancement
- Building Your Advancement Timeline
- Frequently Asked Questions
- ACHRN has no separate written exam or content domains - it's an advancement from CHRN status.
- Applicants need three years of CHRN certification and 480 hyperbaric hours in the prior 12 months.
- You must document at least two of four contribution categories, verified by a manager or medical director.
- 60 CE hours from the past four years are required, with at least 30 Category A hours in hyperbaric oxygen therapy.
Why "ACHRN Exam Domains" Isn't Really a Thing
If you've been searching for a breakdown of ACHRN exam domains the way you might search for domains on a nursing board exam, here's the honest answer: there isn't a separate ACHRN examination to build domains around. The Advanced Certified Hyperbaric Registered Nurse credential, administered through the Baromedical Nurses Association Certification Board (BNACB) and processed via the National Board of Diving and Hyperbaric Medical Technology (NBDHMT), is an advancement credential. You earn it by documenting qualifications and professional contributions on top of an existing CHRN certification - not by sitting for a second multiple-choice test.
That distinction matters enormously for how you prepare. Instead of memorizing content-area percentages, your job is to assemble evidence: years of hyperbaric experience, continuing education hours, and documented contributions to the field. Understanding this structure is the real starting point, and it's covered in more depth in our ACHRN requirements guide, which walks through eligibility and prerequisites in full.
The CHRN Exam You Must Pass First
Before ACHRN advancement is even on the table, you need current CHRN certification and an active RN license. The CHRN exam itself consists of 120 multiple-choice and true/false questions administered over two hours, with a 70% score required to pass. All exam-preparation material on this site is labeled accurately as CHRN preparation, not as an "ACHRN exam," because that's what it actually is.
If you're still working toward CHRN, our ACHRN study guide and labeled CHRN practice questions on the main practice test site are the right place to start. Once you're CHRN-certified and accumulating hyperbaric hours, the advancement conversation begins.
Key Takeaway
Don't waste time hunting for "ACHRN exam domains" content - direct that energy toward passing the CHRN exam first, then toward documenting the advancement criteria below.
The Four Contribution Categories That Replace Domains
Where a traditional certification exam has content domains, ACHRN advancement has something functionally similar but structurally different: four contribution categories. The current advancement/recertification form requires you to document at least two of the four, and each one maps to a different kind of professional activity a hyperbaric nurse might build over a career.
Hyperbaric Unit Administration
Covers leadership or management responsibilities within a hyperbaric unit - supervising staff, overseeing daily operations, or managing program logistics.
- Document a defined administrative role, not just informal leadership
- Manager or medical-director verification is required
Teaching or Presenting Hyperbaric Lectures
Any documented instructional activity - orienting new staff, presenting at conferences, or delivering formal hyperbaric education sessions.
- Keep records of presentation titles, dates, and audiences
- Internal staff education counts if properly documented
Primary Responsibility for Nursing-Care Planning or Coordination
Demonstrates ownership of patient-care planning within the hyperbaric setting, not just task execution.
- Show a pattern of coordinating care across treatment courses
- Verification from your medical director strengthens this category
BNA/UHMS Officer or Committee Participation
Recognizes service to the profession through organizational involvement with the Baromedical Nurses Association or the Undersea and Hyperbaric Medical Society.
- Committee membership, officer roles, or working-group participation qualify
- Ongoing participation is easier to document than a single event
Because these categories function as the closest thing ACHRN has to "domains," it's worth treating them the way you'd treat exam content areas: identify which two you can document most convincingly, then build your evidence file around them well before you submit paperwork.
Experience Hours and Continuing Education Requirements
Alongside the contribution categories, the August 2025 advancement/recertification form sets clear thresholds for experience and education. These are non-negotiable, and they're the part of ACHRN preparation that most resembles studying - except instead of memorizing facts, you're accumulating documented hours.
- Certification tenure: At least three years of current CHRN certification before applying.
- Recent hyperbaric hours: A minimum of 480 hyperbaric hours in the preceding 12 months, verified by a manager or medical director.
- Continuing education: 60 total CE hours from the preceding four years.
- Category A hours: At least 30 of those 60 hours must be Category A hyperbaric oxygen therapy content.
For a deeper walkthrough of how these thresholds interact with eligibility timing, see our full ACHRN requirements breakdown. And if you're weighing whether the effort is worth it relative to your career goals, our ACHRN ROI analysis looks at that question directly.
Fees and the Four-Year Renewal Cycle
ACHRN advancement and recertification fees vary based on membership status, and the credential must be renewed every four years while maintaining the same advanced requirements, current RN licensure, and supporting documentation.
| Applicant Category | Fee (USD) |
|---|---|
| BNA Members | $150 |
| UHMS or ACHM Members | $200 |
| Nonmembers | $250 |
Because the fee structure rewards professional membership, joining BNA before you submit your advancement paperwork can offset a meaningful chunk of the cost. For a full cost picture - including how these fees compare to what you invested earning CHRN in the first place - see our ACHRN certification cost breakdown.
Who Actually Pursues ACHRN Advancement
ACHRN advancement tends to appeal to hyperbaric nurses who have already settled into a unit for several years and want formal recognition for responsibilities they've likely already absorbed informally - running the schedule, training new staff, or coordinating care plans across a busy wound-care and hyperbaric program. Hospital-based hyperbaric and wound care centers, along with multi-site hyperbaric programs, are the kinds of employers where these responsibilities naturally accumulate.
Because ACHRN is built on documented contribution rather than a written test, it tends to signal something different to employers than CHRN alone: not just baseline competency, but sustained leadership and engagement with the field. If you're mapping out where this fits in a broader career trajectory, our ACHRN salary guide and ACHRN jobs overview both dig into how the credential is used in practice.
Key Takeaway
ACHRN rewards nurses who can point to a documented track record - start collecting evidence of leadership, teaching, or committee work now, even years before you plan to apply.
Building Your Advancement Timeline
Since there's no exam to cram for, the useful version of a "study plan" for ACHRN is really a documentation plan. It still benefits from being broken into phases, much like exam prep does - you're just scheduling paperwork and verification instead of review sessions.
Confirm Eligibility Windows
- Verify three full years have passed since CHRN certification
- Confirm your RN license is current with no lapses
Audit Your Hyperbaric Hours
- Pull the last 12 months of logged hyperbaric hours
- Confirm you can reach 480 hours with manager or medical-director sign-off
Assemble CE Records
- Total four years of CE hours toward the 60-hour requirement
- Flag which hours qualify as Category A hyperbaric oxygen therapy content
Document Two Contribution Categories
- Choose the two categories with the strongest existing evidence
- Request written verification from your manager or medical director
Notice what's absent from this plan: flashcards, practice exams, or content-domain review. That's intentional. The closest thing to exam-style preparation in this whole process happens earlier, when you're studying for the CHRN exam itself. Our difficulty guide and passing score breakdown address that phase specifically, and our exam dates and scheduling guide helps you plan around testing windows before you ever reach the advancement stage.
Frequently Asked Questions
No. ACHRN is an advancement from CHRN based on documented experience, continuing education, and professional contributions rather than a separate written exam with content domains.
You need to pass the CHRN exam first: 120 multiple-choice and true/false questions in two hours, with a 70% passing score, plus a valid RN license.
At least 480 hyperbaric hours in the 12 months preceding your application, verified by a manager or medical director, along with three years of current CHRN certification.
At least two of the four categories: hyperbaric unit administration, teaching or presenting hyperbaric lectures, primary responsibility for nursing-care planning or coordination, or BNA/UHMS officer or committee participation.
Every four years, while maintaining the advanced requirements, current RN licensure, and the supporting documentation the recertification form requires.