- ACHRN is an advancement credential from BNACB/NBDHMT, not a separate examination.
- Applicants need three years of CHRN certification plus 480 hyperbaric hours in the prior 12 months.
- 60 continuing education hours are required, with at least 30 Category A hours in hyperbaric oxygen therapy.
- Candidates must document at least two of four contribution categories on the current form.
What Is ACHRN Certification?
ACHRN stands for Advanced Certified Hyperbaric Registered Nurse, a credential administered through the Baromedical Nurses Association Certification Board (BNACB) in conjunction with the National Board of Diving and Hyperbaric Medical Technology (NBDHMT). If you have searched for "ACHRN certification" expecting to find an exam registration page, the most important thing to understand up front is that ACHRN is not earned by sitting for a standalone test. It is earned by advancing from the base Certified Hyperbaric Registered Nurse (CHRN) credential through documented clinical experience and professional contributions to the hyperbaric field.
This distinction matters for how you plan your career and your study time. Instead of memorizing content for an "ACHRN exam" that does not exist as a separate test, your energy should go toward accumulating the right hyperbaric hours, continuing education, and documented contributions that the advancement application requires.
Why ACHRN Is an Advancement, Not a New Exam
The move from CHRN to ACHRN reflects a professional-development model rather than a testing model. According to the June 2024 CHRN resource manual, an advanced application becomes available only after three years of documented CHRN certification. In other words, ACHRN recognizes nurses who have already proven baseline competency through the CHRN exam and then built on that foundation with sustained clinical practice, leadership, and education.
If you are early in your hyperbaric nursing career, this means your first milestone is passing the CHRN exam itself. Resources like the ACHRN Requirements 2026 guide and the broader ACHRN Study Guide 2026 both walk through this sequencing in more detail, but the short version is: CHRN first, ACHRN later, and the two should never be confused as competing exams.
Key Takeaway
Treat CHRN and ACHRN as two stages of one career pathway. You cannot skip to ACHRN; you must hold CHRN certification for a minimum documented period before applying to advance.
ACHRN Requirements at a Glance
The August 2025 advancement/recertification form lays out the specific eligibility criteria for the ACHRN advancement application. These requirements combine licensure, tenure, hours, education, and professional contribution documentation.
Core Eligibility Checklist
Applicants must satisfy each of the following before submitting an advancement application:
- Current, active CHRN certification status
- A valid, unrestricted RN license
- At least three years of hyperbaric nursing experience
- Manager or medical-director verification of at least 480 hyperbaric hours in the preceding 12 months
- 60 continuing education hours from the preceding four years
- Documentation of at least two of the four current contribution categories
Because these are documentation-heavy requirements rather than content-knowledge domains, candidates benefit from starting a tracking system early - logging hours, saving CE certificates, and keeping records of any teaching, committee work, or administrative responsibilities as they happen rather than trying to reconstruct them at application time. For a fuller breakdown of each requirement and how to gather supporting evidence, see the dedicated ACHRN Requirements guide.
The Four Contribution Categories
One of the more distinctive parts of the ACHRN advancement application is the requirement to document contributions beyond direct patient care hours. The current form specifies four categories, and applicants must show involvement in at least two of them.
1. Hyperbaric Unit Administration
Involvement in managing or overseeing operations of a hyperbaric unit, such as scheduling, safety compliance, or program development.
2. Teaching or Presenting Hyperbaric Lectures
Delivering formal education to staff, students, or peers on hyperbaric oxygen therapy topics.
3. Primary Responsibility for Nursing-Care Planning or Coordination
Leading or coordinating individualized patient care plans within the hyperbaric setting, rather than functioning purely as a treatment-room support role.
4. BNA/UHMS Officer or Committee Participation
Serving in an elected or appointed capacity with the Baromedical Nurses Association or Undersea and Hyperbaric Medical Society, such as on a committee or in an officer role.
Because only two of these four are required, candidates should look honestly at their current role and choose the two categories where they already have (or can realistically build) documented evidence, rather than trying to manufacture activity in all four.
Continuing Education Rules
Alongside experience and contribution documentation, the advancement application requires 60 continuing education hours completed within the preceding four years. Of those 60 hours, at least 30 must be Category A hours specifically in hyperbaric oxygen therapy content.
Keep dated certificates, course descriptions, and category classifications organized in one place. When the time comes to submit your advancement/recertification form, having this documentation ready - rather than reconstructed from memory - significantly smooths the process.
Fees, Renewal, and Timelines
ACHRN advancement and recertification fees vary based on membership status:
| Applicant Category | Fee |
|---|---|
| BNA Members | $150 USD |
| UHMS or ACHM Members | $200 USD |
| Nonmembers | $250 USD |
Once granted, ACHRN status must be renewed every four years. Renewal requires maintaining the same advanced requirements - active RN licensure and supporting documentation - rather than a one-time submission. This means the record-keeping habits you build for your first advancement application will need to continue throughout your career as an ACHRN. For a detailed cost comparison across the CHRN and ACHRN stages, see ACHRN Certification Cost 2026: Complete Pricing Breakdown.
The CHRN Prerequisite Exam
Since ACHRN advancement depends entirely on first holding CHRN certification, understanding the CHRN exam format is essential groundwork. The CHRN exam consists of 120 multiple-choice and true/false questions, administered in a two-hour session, with a 70% score required to pass.
Key Takeaway
Every hour you spend studying should be directed at the CHRN exam, since that is the only test in this pathway. Any material marketed as an "ACHRN exam" prep product is mislabeled - this site keeps its practice questions clearly identified as CHRN prerequisite content.
If you're mapping out how to approach this test, the ACHRN Exam Domains 2026 guide and the How Hard Is the ACHRN Exam? Complete Difficulty Guide both offer context on question style and difficulty for the CHRN prerequisite exam within this advancement pathway. You can also review ACHRN Passing Score 2026 for a closer look at what the 70% threshold means in practice, and check ACHRN Exam Dates 2026 when scheduling your test.
Who Hires ACHRN-Credentialed Nurses
Hyperbaric programs - typically housed within wound care centers, hospital-based hyperbaric units, and outpatient hyperbaric clinics - look for nurses who have moved beyond entry-level hyperbaric competency. Because ACHRN specifically documents unit administration experience, teaching activity, care-coordination leadership, or professional-organization involvement, it signals to employers that a nurse can take on responsibilities beyond direct chamber-side care: supervising staff, contributing to protocol development, or representing the unit within professional bodies like BNA or UHMS.
For nurses evaluating whether pursuing this advancement is worth the additional time and documentation burden, it helps to weigh the career trajectory against the requirements outlined above. The Is the ACHRN Certification Worth It? Complete ROI Analysis article and the ACHRN Salary Guide 2026 both explore this from a career-planning angle, while ACHRN Jobs looks at where these advanced credentials tend to be valued in job postings.
Preparing for the Path, Not a Test
Because the ACHRN credential is granted through documentation rather than examination, "preparation" looks different than typical exam study. There is no content review, no practice questions, and no test-day strategy for ACHRN itself. Instead, preparation means:
- Passing the CHRN exam first, using the resources on this site labeled specifically for CHRN
- Tracking hyperbaric hours consistently so the 480-hour, 12-month verification requirement is easy to document when the time comes
- Logging CE hours as you complete them, flagging which count as Category A hyperbaric hours
- Identifying early which two of the four contribution categories fit your role, and seeking opportunities in those areas well before you apply
That said, generic study-scheduling techniques still have a place in your CHRN preparation phase. Spacing your review sessions across the weeks leading up to the CHRN exam date, rather than cramming, gives you more reliable retention for the 120-question format. Once CHRN is behind you, that same discipline shifts from studying content to maintaining organized records for your future ACHRN application. If you want a structured week-by-week approach to the CHRN exam specifically, the ACHRN Study Guide 2026 lays out a practical timeline.
CHRN Preparation
- Study using clearly labeled CHRN practice questions
- Target the 70% passing threshold across all 120 questions
Build Your ACHRN Foundation
- Accumulate hyperbaric hours and CE credits
- Pursue at least two contribution categories
Submit Advancement Application
- Verify 480 hyperbaric hours in the preceding 12 months
- Compile 60 CE hours, including 30 Category A hyperbaric hours
To rehearse the CHRN prerequisite exam under realistic conditions before you commit to a testing date, you can work through timed question sets on our practice test platform. Reviewing your results there alongside the ACHRN Cheat Sheet 2026 can help you spot weak areas before exam day, and the ACHRN Pass Rate 2026 article offers useful context on how the exam is scored.
Frequently Asked Questions
No. ACHRN is an advancement from CHRN certification based on documented experience and professional contributions, not a standalone examination. The only exam in this pathway is the CHRN exam.
The June 2024 CHRN resource manual specifies that an advanced application becomes available after three years of documented CHRN certification.
The advancement/recertification form requires manager or medical-director verification of at least 480 hyperbaric hours in the preceding 12 months, along with at least three years of overall hyperbaric experience.
Applicants must submit 60 continuing education hours from the preceding four years, including at least 30 Category A hours specifically in hyperbaric oxygen therapy.
Fees are $150 for BNA members, $200 for UHMS or ACHM members, and $250 for nonmembers. ACHRN status must be renewed every four years, maintaining active RN licensure and supporting documentation.