- What "Passing" Actually Means on the RMI Exam
- Why There Is No Published Cut Score to Memorize
- How the 2026 Exam Is Built and Delivered
- Where the Points Live: The Six-Domain Blueprint
- Turning Blueprint Weights Into a Study Plan
- Reference Materials You Can Use Inside the Exam
- After the Exam: Results, Retakes and Validity Windows
- Passing Is One Step in the Certification Path
- Frequently Asked Questions
- NRPP follows a competency standard for the RMI exam; no official numerical passing score is published, so treat percentage claims skeptically.
- The exam delivers 95 questions: 85 scored plus 10 unscored trial items, with a two-hour limit.
- Implement Mitigation Installation Strategy carries 30% of the blueprint, more than any other domain.
- Retakes require a 30-day wait, with a maximum of four attempts in 12 months.
What "Passing" Actually Means on the RMI Exam
If you searched for the passing score on the Radon Mitigation Installer (RMI) exam, you probably expected a clean number: 70 percent, 75 percent, maybe a scaled score on a 100-to-500 range. Here is the honest answer: the National Radon Proficiency Program (NRPP) does not publish a numerical cut score that candidates can point to, and this article will not invent one for you.
What NRPP does is administer the exam against a competency standard. In plain terms, the exam is designed to confirm that a person can install radon mitigation systems safely and correctly under supervision, and passing means demonstrating that level of competence across the published exam objectives. That framing matters for how you prepare, because it shifts your goal from "hit a magic percentage" to "be genuinely competent in every domain, with extra depth where the exam concentrates its questions."
Why There Is No Published Cut Score to Memorize
Search results for exam passing scores are full of confident numbers, and some of them come from entirely different credentials that happen to share the "RMI" acronym. Applying another credential's score threshold to the Radon Mitigation Installer exam would be a mistake. For this exam, the verified position is simple: NRPP follows its competency standard and does not assign a public numerical passing score.
There are practical reasons a competency-based exam avoids advertising a single raw percentage:
- Unscored trial items. Ten of the 95 delivered questions are unscored trial items, so a raw "questions correct out of 95" figure would not map cleanly to your result anyway.
- Item difficulty varies. Competency-based exams commonly account for the relative difficulty of the items you receive, so two candidates answering the same number of questions correctly are not necessarily in identical positions.
- Standards are reviewed. Certifying bodies periodically revisit how they set standards, which is another reason a number quoted on a forum can go stale.
The takeaway for your preparation: do not aim to "just scrape by." Aim to be solid in all six domains and strong in the heaviest one. If you want a realistic read on how demanding the exam feels in practice, our RMI exam difficulty guide breaks that down, and the RMI pass rate analysis explains what published data does and does not tell you.
How the 2026 Exam Is Built and Delivered
Understanding the structure of the exam helps you interpret what "passing" is measured against. Here are the current delivery details that candidates should plan around.
| Exam Element | Current Detail |
|---|---|
| Delivery method | Certiverse, live remote proctoring |
| Questions delivered | 95 total |
| Scored questions | 85 |
| Unscored trial items | 10 (not identified to the candidate) |
| Time limit | Two hours |
| Exam fee | $125 |
| Identification and environment | Photo ID, live proctor and a room scan |
| Breaks | One bathroom break of up to five minutes |
| Retakes | 30-day wait; at most four attempts in 12 months |
Watch for outdated information
Older versions of the NRPP Candidate Handbook describe a different delivery vendor (Examity), an 85-question total and earlier fee amounts. The 95-question format with 10 unscored trial items has been in place since October 1, 2024, and current logistics supersede the older handbook language. If a study blog, video or classmate quotes an 85-question exam or a different proctoring platform, they are working from stale material.
Pacing across 95 questions
Two hours for 95 delivered items works out to a little over a minute per question. You will not know which ten are unscored, so treat every item as if it counts. Calculation-style questions will cost you more time than recall questions, which means you should bank time on the quick ones and avoid sinking five minutes into a single airflow or pressure problem.
Where the Points Live: The Six-Domain Blueprint
The official exam objectives come from the NRPP Candidate Handbook (document 3-007-4 V7, revised May 4, 2023, Appendix A). The six domains and their weights total 100 percent. This is the verified published blueprint; NRPP has not published a revised 2026 outline for the installer exam, so this remains the reference to study against.
| Domain | Weight |
|---|---|
| Domain 1: Communicate with the Client | 14% |
| Domain 2: Identify Radon Entry Points | 17% |
| Domain 3: Maintain Jobsite Safety | 15% |
| Domain 4: Implement Mitigation Installation Strategy | 30% |
| Domain 5: Perform Post-Installation Tasks | 17% |
| Domain 6: Operate in an Ethical and Professional Manner | 7% |
Because the exam measures competency across the whole blueprint, no single domain is safe to ignore. But the weights tell you where a gap hurts most. For a domain-by-domain walkthrough, see our complete guide to all six RMI content areas.
Domain 4: Implement Mitigation Installation Strategy (30%)
Nearly one in three questions comes from this domain, so it is the clearest place to build strength. It covers the actual design-and-install work of a radon reduction system.
- Selecting a mitigation approach appropriate to the foundation and building conditions
- Pipe sizing, routing and support for active soil depressurization systems
- Fan selection, placement and exhaust termination considerations
- Sealing of cracks, penetrations and sump or drain openings
- Using the standards and formulas provided in the exam platform (see below)
Domain 2: Identify Radon Entry Points (17%)
Installers must recognize how radon moves from soil into a structure, because system design starts with understanding the building.
- Common entry routes such as slab cracks, floor-wall joints, sumps and utility penetrations
- Differences among slab-on-grade, basement and crawlspace foundations
- How pressure differentials and stack effect influence entry
Domain 5: Perform Post-Installation Tasks (17%)
The job is not finished when the fan turns on. This domain covers verification and handoff.
- Checking system performance and confirming proper operation
- Labeling, documentation and homeowner instructions
- Understanding the role of post-mitigation testing
Domain 3: Maintain Jobsite Safety (15%)
Safety questions test practical judgment around a working crew and a occupied home.
- Personal protective equipment and hazard awareness during installation
- Combustion appliance safety and backdrafting concerns
- Electrical and tool safety during fan and wiring work
Domain 1: Communicate with the Client (14%) and Domain 6: Operate in an Ethical and Professional Manner (7%)
Together these make up 21 percent of the exam, and they are often under-studied because they feel like common sense. They are scenario-driven, so read the situation carefully.
- Explaining the process, expectations and limitations of mitigation to homeowners
- Honest representation of services and results
- Working within the supervision structure and the Statement of Professional Responsibility
Turning Blueprint Weights Into a Study Plan
Since passing depends on competency across the blueprint rather than a single raw score, the smartest plan weights your hours by domain size while still covering everything. One simple way to schedule the weeks before your exam date:
Entry Points and Safety
- Study Domain 2 foundations and building types, since entry-point logic supports every installation decision
- Cover Domain 3 jobsite safety while the basics are fresh
Installation Strategy
- Spend the largest block of study time on Domain 4, the 30 percent domain
- Practice calculations using the formulas and standards you will see in the exam platform
Post-Installation, Client and Ethics
- Review Domain 5 verification and documentation tasks
- Work scenario questions for Domains 1 and 6
- Take timed full-length practice sets to rehearse the two-hour pace
For a fuller approach to materials and sequencing, our RMI study guide walks through how to prepare for a first-attempt pass, and you can drill the blueprint topics with a timed session on the RMI practice test.
Reference Materials You Can Use Inside the Exam
One detail that surprises many candidates: the exam platform itself provides certain reference tools. Inside the exam you have access to SGM-SF-2023, MAH-2023, a calculator and formulas. This is not the same as being allowed to bring personal reference books, which is not permitted.
Candidates who treat the in-platform references as a crutch they never practiced with tend to lose time on the day. Rehearse with them so that finding a requirement feels routine.
After the Exam: Results, Retakes and Validity Windows
If you do not pass on the first attempt, the retake rules are straightforward: you must wait 30 days between attempts, and you can sit for the exam at most four times in a 12-month period. Each attempt carries the $125 exam fee, so a careless first try has a real cost. Our RMI certification cost breakdown shows how exam fees stack with certification and training expenses.
Also keep the validity windows in mind:
- Training certificates are usable for two years.
- Examination results are valid for one year, so you should complete your remaining certification steps in that window.
Passing the exam does not instantly make you certified. A passing result starts a clock you need to manage.
Passing Is One Step in the Certification Path
Earning a passing result is necessary but not sufficient. To become a certified Radon Mitigation Installer, candidates also need:
- Approved measurement training of at least 12 hours
- Approved mitigation training of at least 20 hours
- A successful RMI examination
- A signed Statement of Professional Responsibility
- Supervision by an NRPP-certified RMS employed by the same company
After approval, initial certification costs $250. Certification lasts two years, and the biennial renewal fee is also $250. Renewal requires eight Category I continuing education hours, including the applicable four-hour Standards Overview course, ethics compliance and current supervisor documentation. For the full eligibility picture, see our guide to RMI requirements and prerequisites.
Key Takeaway
Do not hunt for a single passing percentage. Build competence in all six domains, invest the most hours in Domain 4, practice with the in-platform standards, and protect your result window by completing the remaining certification steps while your exam result and training certificates are still valid.
If you are weighing whether the investment makes sense for your career, the RMI certification ROI analysis and the RMI salary guide cover the economics. State licensing requirements and RMI supervision requirements remain separate from the exam itself, so check your state's rules in addition to NRPP's.
Frequently Asked Questions
NRPP follows a competency standard and does not publish an official numerical passing score for this exam. Rather than aiming for a specific percentage, prepare to demonstrate competence across all six exam domains, with particular depth in Implement Mitigation Installation Strategy, which carries 30 percent of the blueprint.
The exam delivers 95 questions, of which 85 are scored and 10 are unscored trial items. You are not told which items are unscored, so answer every question carefully. You have two hours to complete the exam through Certiverse with live remote proctoring.
No. Personal reference books are not permitted. The exam platform provides SGM-SF-2023, MAH-2023, a calculator and formulas, so practice using those in-platform resources before test day. You will also need photo ID, a live proctor and a room scan.
You must wait 30 days before retaking it, and you may attempt the exam at most four times within 12 months. Each attempt requires the $125 exam fee, so use the waiting period to strengthen your weakest domains before rescheduling.
Examination results are valid for one year, and training certificates are usable for two years. Plan to complete the remaining requirements, including the signed Statement of Professional Responsibility and supervision arrangements, within those windows. For scheduling details, see our RMI exam dates guide.