ACHRN Study Guide 2026: How to Pass on Your First Attempt

What the ACHRN Actually Requires in 2026

Anyone typing "ACHRN exam" into a search bar expecting a proctored test day is going to be surprised. The Advanced Certified Hyperbaric Registered Nurse credential, administered through the Baromedical Nurses Association Certification Board (BNACB) in partnership with the National Board of Diving and Hyperbaric Medical Technology (NBDHMT), is an advancement pathway built on top of your existing CHRN certification. There is no separate multiple-choice ACHRN exam to schedule or cram for. Instead, the June 2024 CHRN resource manual and the August 2025 advancement/recertification form describe a documentation-based process: you prove sustained hyperbaric experience, current continuing education, and professional contribution, and the board advances your status.

That distinction matters for how you "study." Passing on your first attempt with ACHRN means submitting a complete, error-free advancement packet - not answering test questions correctly. Our companion piece on ACHRN requirements breaks down the eligibility criteria in more detail; this guide focuses on turning those requirements into a submission-ready plan.

The CHRN Exam You Must Clear First

Before advancement is even on the table, you must hold current CHRN certification for at least three years. The CHRN examination itself is 120 questions - a mix of multiple-choice and true/false items - administered in a two-hour window, with a 70% score required to pass. If you have not yet reached that milestone, your near-term "study guide" is really a CHRN study guide, and you should treat it as such.

For a full breakdown of exactly what score you need and how it's calculated, see ACHRN passing score. If you want a structured look at every content area the CHRN exam draws from before you attempt advancement, our exam domains guide walks through them one by one. Once you're comfortable with the material, our CHRN practice question bank lets you rehearse the question format under timed conditions.

Building Your ACHRN Eligibility Checklist

The August 2025 advancement/recertification form spells out exactly what the board wants to see. Treat this as a checklist you build a physical (or digital) folder around, months before you plan to submit.

A gap in any one of these areas is the single most common reason a first submission gets sent back for revision. If you're still assembling your professional history, our requirements breakdown is a good companion checklist to work through alongside this one.

Mapping Your 60 Continuing Education Hours

The advancement form requires 60 continuing education hours completed within the preceding four years, and at least 30 of those must be Category A hours specifically in hyperbaric oxygen therapy. That split matters - general nursing CE alone won't satisfy the HBOT-specific portion.

• Track by category, not just total hours. Keep a running tally separating Category A hyperbaric hours from general CE so you can see the shortfall early.
• Front-load HBOT-specific coursework. Because Category A hyperbaric hours are the harder bucket to fill, prioritize those courses first in your four-year window.
• Save every certificate. Course titles alone won't satisfy a documentation review - you need dated proof for each hour claimed.

Documenting Two Contribution Categories

Beyond hours and CE, the current advancement form asks you to demonstrate meaningful professional contribution - not just clinical time. You must document at least two of four recognized categories.

Most working hyperbaric nurses naturally accumulate evidence in unit administration and care coordination simply through day-to-day responsibilities. The categories that require deliberate planning are usually teaching/presenting and organizational service - if you want those two, start volunteering for in-service presentations or committee seats well before you plan to apply.

Advancement Fees and Submission Mechanics

Advancement and recertification fees vary by membership status, so confirm which tier applies to you before you submit payment.

For a full walkthrough of how these fees compare across membership scenarios and what else might factor into your total cost, read ACHRN certification cost. Submitting the correct fee tier on the first try avoids processing delays - a surprisingly common paperwork error.

Renewing ACHRN Status Every Four Years

Advancement isn't a one-time event. ACHRN status renews on a four-year cycle, and renewal requires maintaining the same advanced requirements: current RN licensure, continued hyperbaric involvement, and supporting documentation consistent with what got you advanced in the first place. Nurses who treat their contribution categories and CE tracking as an ongoing habit - rather than a one-time scramble - find the renewal cycle far less stressful than the initial advancement application.

A Realistic Preparation Timeline

Because ACHRN advancement is documentation-driven rather than exam-driven, your "study" schedule should really be a documentation-assembly schedule. Here's how to sequence it if you're roughly a year out from your target submission date.

If you're still working toward CHRN certification itself, use this same timeline structure to schedule exam review instead, and lean on the difficulty guide and pass rate analysis to calibrate how much runway you need.

Mistakes That Delay First-Time Approval

• Submitting before the three-year CHRN mark. Advancement eligibility starts counting from your CHRN certification date, not your hire date.
• Confusing general CE with Category A hyperbaric hours. Only the hyperbaric-specific coursework counts toward the 30-hour minimum inside your 60 total hours.
• Missing verifier signatures. A manager or medical director must formally verify your 480 recent hyperbaric hours - informal confirmation isn't sufficient.
• Documenting only one contribution category. The form requires evidence across at least two of the four recognized categories, not just the easiest one.
• Paying the wrong fee tier. Membership status with BNA, UHMS, or ACHM changes your fee - double-check before submitting.

Many of these mistakes trace back to candidates researching the wrong version of "ACHRN" online. If you're unsure what the letters even stand for in this context, our explainer on what ACHRN stands for and the broader what is ACHRN overview are useful starting points before you dive into paperwork.

Frequently Asked Questions