- The Number: 70% on 50 Questions
- What 70% Means in Real Questions
- Exam Format, Delivery and Results
- Where the Points Come From: The Five Competencies
- The Reference Books Behind the Questions
- Reading the Pass-Ratio Statistic Responsibly
- What a Miss Costs: Retake and Fee Mechanics
- A Domain-Ordered Plan for Reaching 70%
- Eligibility and Timing Before You Sit
- After the Score: Certification and Renewal
- Frequently Asked Questions
- The Council-certified Residential Microbial Remediator (CRMR) passing score is 70% on a 50-question, closed-book exam.
- You have two hours; results appear electronically right away and are confirmed by email.
- The exam fee is $100; a retake costs $100, and the $300 certification fee follows a pass.
- The five published competencies are unweighted, so study all of them rather than guessing a blueprint.
The Number: 70% on 50 Questions
The American Council for Accredited Certification (ACAC) sets the passing score for the Council-certified Residential Microbial Remediator credential at 70%. The CRMR Candidate Handbook describes the examination as 50 multiple-choice questions taken in two hours, closed book, with at least four answer choices per question. That is the whole scoring rule candidates can verify from the issuer's published material.
If you are searching for a trick, a scaled-score conversion, or a hidden cut score, the handbook does not describe one. Plan around the plain 70% figure, and treat anything more exotic from third-party sites as unverified. For a broader look at how demanding that threshold feels in practice, see our guide on how hard the CRMR exam is.
What 70% Means in Real Questions
On a 50-question exam, 70% translates to 35 correct answers. You can miss up to 15 questions and still clear the line. That arithmetic matters for how you manage the two-hour window: you do not need perfection, you need consistent competence across the whole body of knowledge.
| Item | CRMR Detail |
|---|---|
| Total questions | 50 multiple choice |
| Passing score | 70% |
| Correct answers needed | 35 |
| Questions you may miss | 15 |
| Time allowed | 2 hours (written exam duration) |
| Answer choices | At least four per question |
| Reference materials | Closed book |
With roughly 2.4 minutes available per question, time pressure is rarely the main risk. The more common problem is a content gap in one competency area that drags an otherwise solid performance below 35 correct. Because the issuer does not publish weights, a weak spot in any single area can cost you several questions with no way to know in advance how many.
Exam Format, Delivery and Results
Randomized questions, immediate results
Questions and answer choices are randomized, so memorizing the position of a correct answer is pointless. Electronic results are available immediately after you finish, and ACAC confirms them by email. You will know where you stand before you leave the testing session.
Where you take it
The testing provider is Kryterion, Inc. Candidates can sit at an authorized testing center or use secure online video proctoring. An instructor-proctored vocational option is available by arrangement. Be careful with one detail: the two-hour limit is the duration of the written examination, not the length of any training course you might take beforehand.
Where the Points Come From: The Five Competencies
The handbook publishes five competency statements for the CRMR. They are unweighted, and they should not be mistaken for a verified, exhaustive examination blueprint. No official percentage weights have been published or can be responsibly inferred, so spread your preparation across all five. Our complete guide to the five CRMR content areas goes deeper on each one.
Domain 1: Basic principles of microbial remediation
Understand the basic principles of microbial remediation as described in the listed reference texts.
- This competency is tied to the published reference list, so the books themselves are the syllabus.
- Expect questions that test vocabulary and principles from the reference texts rather than invented field anecdotes.
Domain 2: Equipment, supplies, calibration and operation
Maintain familiarity with the equipment and supplies necessary to conduct a microbial remediation project, and with the methods for calibration and operation of such equipment.
- Know what equipment a project calls for and how it is calibrated and operated.
- Study this as practical procedure, not just a list of tool names.
Domain 3: Safety hazards and protection
Appreciate the safety hazards presented by microbial remediation projects, and follow the procedures necessary to protect building occupants and remediation workers from such hazards.
- The competency also specifies regulatory awareness, safe work practices and appropriate PPE.
- Think in terms of protecting both occupants and workers.
Domain 4: Regulated substances
Recognize that microbial remediation may bring the remediator into contact with regulated substances such as lead and asbestos.
- The emphasis is on recognition: knowing that these substances can turn up on a job.
- Understand why that recognition changes how a project should proceed.
Domain 5: Water damage
Properly address water damage in the indoor environment.
- Moisture is central to microbial problems, so this area connects to nearly everything else.
- The IICRC S500 reference is the natural anchor for this competency.
The Reference Books Behind the Questions
Because Domain 1 points directly at the listed reference texts, the required references deserve more attention than any third-party summary. The handbook lists the following:
- The ACAC Code of Conduct
- AIHA, Recognition, Evaluation & Control of Indoor Mold, second edition (2020)
- ANSI/IICRC S500-2021, fifth edition
- ANSI/IICRC S520-2015 with R520-2015, third editions, or S520-2024, fourth edition
The same study guide organizes preparation under three reference headings: AIHA, Recognition, Evaluation and Control of Indoor Mold; IICRC, S500-2021; and IICRC, S520. These are unweighted preparation categories, not extra official exam domains. For S500, the study guide highlights sections A, B and 1 through 8, plus glossary pages 99-118. ACAC expects study of the full references, however, not only the highlighted reading locations.
Key Takeaway
Do not let the highlighted S500 pages become your whole plan. Read the highlights first for orientation, then work through the full texts. A 70% line leaves little room for entire sections you skipped.
The reference editions listed do not establish a numbered 2026 exam version, so avoid any claim that a particular "2026 edition" of the test exists. Choose between the S520-2015 and S520-2024 references by confirming current guidance with ACAC. For a structured reading order, our CRMR study guide lays out a path through the material, and the CRMR cheat sheet works as a compact final review.
Reading the Pass-Ratio Statistic Responsibly
A prior review attributed to ACAC's 2025 Exam Pass Ratio report a figure of 37 passes from 37 exam administrations, or 100%, for this credential. Treat this carefully. The statistic has not been independently reverified here, because the PDF could not be re-fetched, although ACAC's current-statistics page still links the report. The report is also reported to include retakes and state-licensing-only exams.
The sensible takeaway: a high reported ratio is mildly reassuring, but your preparation, not the statistic, decides whether you reach 35 correct answers.
What a Miss Costs: Retake and Fee Mechanics
Because a pass requires 70%, it helps to know the financial stakes of falling short. Fees are in USD:
| Fee | Amount |
|---|---|
| Examination | $100 |
| Certification | $300 |
| Total initial cost | $400 |
| Retake | $100 |
| Renewal | $300 |
A failed attempt therefore costs a further $100 rather than a full restart of the initial total. That is a modest penalty, but it still adds up in time and confidence, and it is the best argument for sitting the exam only when your reference reading is complete. Optional preparation courses from independent providers are priced separately, and provider-quoted fees can conflict with current issuer instructions, so confirm certification facts with ACAC. A fuller breakdown lives in our CRMR certification cost guide.
A Domain-Ordered Plan for Reaching 70%
Since weights are unpublished, a balanced plan beats a gamble on favorite topics. One sequence that suits the five competencies starts with the reference reading that feeds Domain 1, then layers practical areas on top.
Principles and AIHA reference
- Read the AIHA indoor mold text for Domain 1 principles.
- Build a glossary of terms as you go.
Water damage and IICRC S500
- Cover S500 sections A, B and 1 through 8, then the rest of the book.
- Learn glossary pages 99-118 for Domain 5 vocabulary.
Remediation practice and equipment
- Work through the S520 reference for remediation procedure.
- Review equipment, supplies, calibration and operation for Domain 2.
Safety, regulated substances and review
- Revisit PPE, safe work practices and regulatory awareness for Domain 3.
- Review lead and asbestos recognition for Domain 4, then test yourself across all five areas.
The reasoning: principles and water damage come first because moisture concepts recur in every other area, while safety and regulated-substance recognition benefit from fresh review close to exam day. Adjust the pacing to your experience; a working remediator may compress the equipment week, while a newcomer may extend it.
When you are ready to check retention, scenario-style questions that mirror the multiple-choice format are valuable. Try the CRMR practice test to find which competency areas need more work before you book.
Eligibility and Timing Before You Sit
Passing score is only one gate. Eligibility requires attestation of current employment in microbial remediation, application and identity verification, a successful examination and certification-board approval. The handbook specifies no minimum duration of experience, no project sheets and no mandatory preparatory course. Details are in our CRMR requirements guide.
Also note that this is a vocational, non-CESB-accredited designation. Completing a course, or passing an examination solely for state licensing, does not itself confer ACAC certification. Only the certification-board approval path does.
After the Score: Certification and Renewal
Passing the exam is a step toward certification, not the end of it. Once the board approves you, certification lasts two years. Current renewal procedures require 40 recertification credits: 10 for continued field activity plus 30 hours of professional development. Keep evidence for audit and submit the required current photo. Renewal costs $300.
Employers in the microbial remediation field are the natural audience for the credential, and the current-employment attestation reflects that. As for pay, occupation-level earnings should not be confused with a proven premium caused by holding the CRMR. Our salary guide and ROI analysis treat that distinction carefully.
Frequently Asked Questions
The passing score is 70% on the 50-question multiple-choice exam, which equals 35 correct answers. The exam is closed book and runs two hours.
Electronic results are available immediately after the exam and are confirmed by email. Certification itself still requires application approval and the board's decision.
No official percentage weights have been verified or published for the five competency statements, so none should be assumed. Prepare for all five: principles, equipment and calibration, safety, regulated substances and water damage.
A retake costs $100. The initial total is $400 ($100 examination plus $300 certification), and renewal is $300 every two years with 40 recertification credits.
No. The reported 37 of 37 figure for 2025 is a small sample that reportedly includes retakes and state-licensing-only exams. It is not a first-attempt probability or an individual guarantee, so base your readiness on your own practice results.