RMI Certification

What the Radon Mitigation Installer Credential Actually Is

The Radon Mitigation Installer (RMI) credential is issued through the National Radon Proficiency Program (NRPP). It certifies that a person can physically install radon reduction systems in buildings, working under the oversight of a certified supervisor. That last point matters: the RMI is a supervised credential. It is not the same thing as the Radon Mitigation Specialist (RMS), the Radon Measurement Professional (RMP), or a state radon license, and this article covers only the installer certification.

If you are still orienting yourself on the terminology, our explainers on what RMI certification is and what the RMI acronym stands for cover the basics. Here, we focus on the mechanics of earning and keeping the credential, based on the NRPP's published exam blueprint and current exam logistics.

The Path From Training to Certificate

Certification is a sequence, not a single event. You complete approved training, pass the exam, sign a professional-conduct statement, and attach yourself to a qualified supervisor. Missing any one of these stops the process.

The prerequisites, in order

1. Measurement training: at least 12 hours of approved coursework.
2. Mitigation training: at least 20 hours of approved coursework.
3. Passing the RMI examination.
4. A signed Statement of Professional Responsibility.
5. Supervision by an NRPP-certified RMS who is employed by the same company as you.

The supervision requirement is the one candidates most often underestimate. You cannot hold the RMI independently, and the supervisor must work for your company. If you are a job-seeker rather than an employee, you will generally need an employer arrangement lined up before certification can be completed. Our RMI requirements guide walks through eligibility in more depth, and the RMI training overview explains how to evaluate course providers.

Validity windows that can trip you up

Training certificates are usable for two years, and exam results are usable for one year. That means the clock starts the moment you finish a course or pass the test. If you pass the exam but delay the rest of the paperwork, or take training and then wait too long to sit the exam, you may have to repeat steps. Sequence your training, exam and employer paperwork so the windows overlap comfortably.

How the Exam Is Delivered

The RMI exam is delivered through Certiverse with live remote proctoring. Older NRPP materials, including the candidate handbook, reference a different delivery vendor and an older item count; the current logistics supersede those. What you should plan for today:

The unscored trial items are indistinguishable from scored ones, so treat every question as if it counts. With 95 items in 120 minutes, you have a little over a minute per question. That is workable for knowledge-recall items but tight for questions that require you to apply a formula, so practice pacing on calculation-style questions specifically.

The NRPP does not assign a published numerical passing score; passing follows the issuer's competency standard. If you have seen a specific cut score quoted elsewhere, treat it with caution. Our RMI passing score article explains how to think about this, and the pass rate discussion covers what can and cannot be said from available data.

The Six-Domain Blueprint

The exam objectives are organized into six domains whose weights total 100%. The weighting should drive your study hours, because a single domain accounts for nearly a third of the exam.

For a deeper walk-through of each area, see our complete guide to the six RMI exam domains.

What You Pay and When

The NRPP's fee schedule, effective January 1, 2025, separates the costs of examination and certification. Training is paid to your course provider and is a separate expense.

Add up the exam fee and initial certification and you get a baseline NRPP outlay before training, before any retake fees and before any state licensing costs. The RMI certification cost breakdown shows how to budget the full picture, and the ROI analysis helps you weigh that against career benefits.

What You Can Use During the Exam

This is an exam with built-in references, but not a free-for-all. The platform provides the following inside the testing interface:

• SGM-SF-2023
• MAH-2023
• A calculator and formulas

Personal reference books are not permitted. Because the standards documents are available in-platform, rote memorization of every paragraph is less valuable than knowing what is in them and how to navigate quickly to the relevant section. A candidate who has never opened these documents before exam day will burn minutes hunting for answers.

Our RMI cheat sheet distills the must-know facts you should have internalized so that the in-platform references are a backup rather than a crutch.

Scheduling Your Prep by Domain Weight

You do not need an elaborate method. You need to allocate time in proportion to the blueprint and front-load the domain you will find hardest. A mitigation-training graduate who already works in crawlspaces may find installation intuitive but under-prepared on client communication and ethics; someone coming from the testing side may be the reverse.

If you want a fuller plan, our RMI study guide expands on resources and review cycles, and you can gauge your readiness with the RMI practice tests on our main site. For perspective on what to expect, see how hard the RMI exam is.

Retakes, Validity Windows and Renewal

If you do not pass

Retakes require a 30-day wait, and you may make at most four attempts in 12 months. That is enough room to recover from a bad day, but not enough to treat the exam as a guessing game. Use the waiting period to target the domains where you were weakest. Because exam results are valid for one year, passing late in your attempt window leaves less slack to finish the remaining prerequisites, so plan accordingly.

Keeping the credential

Certification lasts two years. To renew, you need:

• Eight Category I continuing-education hours, including the applicable four-hour Standards Overview course
• Ethics compliance
• Current supervisor documentation
• The $250 biennial renewal fee

The supervisor-documentation requirement means a job change can create a renewal problem if your new employer does not have a qualifying RMS. Keep your documentation current throughout the two-year cycle, not just at the deadline. For scheduling questions around test sessions, see our RMI exam dates guide.

Who Hires Certified Installers

The supervision requirement tells you where RMIs work: within companies that employ an NRPP-certified RMS. That typically means dedicated radon mitigation contractors, but also home-services, basement-waterproofing, foundation-repair and HVAC businesses that have added radon reduction to their offerings. Because the credential is tied to a same-company RMS, employer relationships are not incidental; they are part of how certification works.

Pay varies widely by region, employer type and whether you hold additional credentials or state licensing, so we avoid quoting a single figure here. The RMI salary guide discusses earnings factors qualitatively, and our RMI jobs overview describes typical roles and employers. If you want to start measuring your readiness before applying, try a set of RMI practice questions.

Frequently Asked Questions