- ACHRN is an advancement credential from BNACB/NBDHMT, not a standalone exam you sit for.
- You need three years of current CHRN certification and a valid RN license before applying.
- Applicants must document 480 hyperbaric hours in the prior 12 months plus 60 CE hours, 30 of them Category A.
- Advancement/recertification fees run $150 (BNA members), $200 (UHMS/ACHM members), or $250 (nonmembers).
What ACHRN Actually Means
Advanced Certified Hyperbaric Registered Nurse (ACHRN) is a credential issued by the Baromedical Nurses Association Certification Board (BNACB) and administered through the National Board of Diving and Hyperbaric Medical Technology (NBDHMT). If you've searched "ACHRN certification" expecting a second exam layered on top of the Certified Hyperbaric Registered Nurse (CHRN) credential, the reality is different: ACHRN is a documented advancement, built on a portfolio of clinical hours, continuing education, and professional contribution - not a separate test.
That distinction matters for anyone comparing our ACHRN Requirements 2026: Eligibility, Prerequisites & How to Qualify guide against other search results. Several other credentials share the "ACHRN" acronym in unrelated fields, and their exam fees, question counts, or pass rates do not apply here. Everything on this site is scoped specifically to the hyperbaric nursing advancement pathway defined by BNACB and NBDHMT.
How ACHRN Relates to CHRN
CHRN is the entry credential for hyperbaric nursing practice. It requires passing a standalone exam. ACHRN, by contrast, sits on top of an existing, current CHRN certification. Per the June 2024 resource manual, a nurse becomes eligible to file an advanced application only after holding CHRN certification for three years. There is no "ACHRN exam" to schedule or study for in the way candidates study for CHRN - the credential is granted through a documentation review, not a proctored test.
This is why exam-prep material on this site is labeled correctly: CHRN practice questions prepare you for the exam you actually sit, while ACHRN-focused pages walk you through the advancement paperwork, hour tracking, and contribution documentation. If you're still working toward initial certification, start with our ACHRN Study Guide 2026: How to Pass on Your First Attempt, which covers the foundational CHRN knowledge every advancement applicant needs to have already mastered.
Key Takeaway
Don't search for "ACHRN exam questions." There isn't one. Search instead for CHRN exam prep, then plan your advancement portfolio separately once you hold CHRN status.
The Advancement Pathway, Step by Step
The August 2025 advancement/recertification form lays out concrete, checkable requirements. Nothing here is subjective scoring or weighted domains - it's a documentation checklist reviewed against your submitted evidence.
Baseline Eligibility
Before submitting anything, confirm you meet the floor requirements.
- Current CHRN certification in good standing
- Valid, unrestricted RN license
- At least three years of hyperbaric clinical experience
- Manager or medical-director verification of at least 480 hyperbaric hours within the preceding 12 months
Continuing Education Requirement
Applicants submit 60 continuing education hours accumulated over the preceding four years.
- At least 30 of those hours must be Category A hours specific to hyperbaric oxygen therapy
- Remaining hours can come from broader nursing or clinical education relevant to your practice
- Keep dated certificates - verification requires documentation, not self-attestation alone
Professional Contribution Categories
The current form requires evidence in at least two of four contribution categories.
- Hyperbaric unit administration
- Teaching or presenting hyperbaric lectures
- Primary responsibility for nursing-care planning or coordination
- BNA or UHMS officer/committee participation
Because this pathway is document-heavy rather than test-heavy, the "difficulty" of ACHRN looks different from a typical certification exam. Our How Hard Is the ACHRN Exam? Complete Difficulty Guide 2026 article addresses this directly - the real challenge is assembling verifiable hours, CE records, and contribution evidence across years of practice, not answering multiple-choice items under a clock.
Fees and Renewal Cycle
Advancement and recertification fees are tiered by membership status. There is one fee schedule, and it applies whether you're filing an initial advancement application or a subsequent renewal.
| Applicant Category | Fee (USD) |
|---|---|
| BNA members | $150 |
| UHMS or ACHM members | $200 |
| Nonmembers | $250 |
ACHRN renews on a four-year cycle. Renewal isn't automatic - you must continue meeting the advanced-level requirements (current RN licensure, ongoing hyperbaric practice, updated documentation) at each renewal point. For a full line-item breakdown of what you'll spend across initial CHRN certification and later ACHRN advancement, see ACHRN Certification Cost 2026: Complete Pricing Breakdown. If you're trying to time your application around your current CHRN cycle or CE reporting period, our ACHRN Exam Dates 2026: Testing Windows, Deadlines & Scheduling guide explains how the CHRN testing calendar interacts with your three-year advancement eligibility clock.
Who Pursues ACHRN and Why
ACHRN candidates are almost always working hyperbaric nurses who've already spent years inside a wound care or hyperbaric medicine unit. Typical profiles include:
- Charge nurses or clinical leads in hospital-based hyperbaric/wound care programs who oversee scheduling, chamber operations, or staff training
- Nurses who've taken on nursing-care planning or coordination responsibilities across a hyperbaric caseload
- Staff who present at hyperbaric conferences, teach internal in-services, or sit on BNA/UHMS committees
- Nurses being groomed for hyperbaric program management or director-level roles
Employers value ACHRN because it signals sustained experience and leadership contribution, not just passing an entry exam once. If you're weighing whether the time investment is worth it relative to your career trajectory, read Is the ACHRN Certification Worth It? Complete ROI Analysis 2026 alongside ACHRN Salary Guide 2026: Complete Earnings Analysis and ACHRN Jobs to see how the credential shows up in job postings and internal promotion criteria.
The CHRN Exam Behind ACHRN
Since ACHRN advancement requires holding CHRN certification first, understanding the prerequisite exam matters even to advancement-focused candidates - especially those recertifying and refreshing their baseline knowledge. The CHRN exam consists of:
- 120 questions, combining multiple-choice and true/false formats
- A two-hour testing window
- A 70% score required to pass
We keep this labeling precise across the site: any practice questions referencing this format are CHRN practice questions, not an "ACHRN exam." Our ACHRN Passing Score 2026: Exactly What You Need to Pass page walks through exactly how that 70% threshold is applied on the CHRN exam, and ACHRN Pass Rate 2026: What the Data Shows discusses what's publicly known about candidate outcomes without inflating numbers that aren't documented.
Key Takeaway
Treat CHRN exam mastery as the foundation, not a one-time hurdle. Your ACHRN advancement application will lean on the same clinical knowledge base years later.
Preparing for the Prerequisite Exam
Because there's no ACHRN exam to cram for, your preparation time is better spent two ways: making sure your CHRN knowledge is exam-ready if you haven't certified yet, and building a simple tracking system for hours, CE credits, and contribution evidence if you're already CHRN-certified and eyeing advancement.
For candidates still working toward CHRN, a short structured review in the weeks before your test date helps consolidate hyperbaric physiology, chamber safety, and patient-care content into exam-ready recall. Our ACHRN Exam Domains 2026: Complete Guide to All 0 Content Areas resource breaks the underlying clinical knowledge into study-sized sections, and you can pair that with timed practice sessions on our practice test platform to simulate the two-hour, 120-question format before test day.
Core Clinical Review
- Work through hyperbaric physiology and chamber operations content
- Use timed practice questions to identify weak areas early
Patient Care and Safety Protocols
- Focus on wound care, complications, and safety procedures likely to appear in true/false format
- Re-test previously missed practice questions rather than starting fresh sets
Full-Length Simulation
- Run at least one complete 120-question, two-hour simulation
- Review the ACHRN Cheat Sheet 2026: One-Page Review of Must-Know Facts for last-minute recall
If you're already CHRN-certified and mapping your route to advancement, skip the exam-drilling schedule above and instead build a simple binder or spreadsheet: hyperbaric hours logged monthly, CE certificates filed as earned, and contribution evidence (lecture slides, committee minutes, care-planning documentation) collected in real time rather than reconstructed years later.
Frequently Asked Questions
No. ACHRN is an advancement from CHRN based on documented experience, continuing education, and professional contribution - reviewed by BNACB/NBDHMT rather than tested through a proctored exam.
The resource manual requires at least three years of current CHRN certification before you're eligible to file an advanced application.
You need at least three years of hyperbaric experience overall, plus manager or medical-director verification of at least 480 hyperbaric hours within the preceding 12 months.
Fees are $150 for BNA members, $200 for UHMS or ACHM members, and $250 for nonmembers, covering the advancement/recertification application.
ACHRN renews every four years, and you must continue meeting the advanced requirements, maintain RN licensure, and keep supporting documentation current throughout the cycle.