- The exam is 100 multiple-choice questions in three hours, closed book, with a 75% passing criterion set by modified Angoff.
- Initial US/Canada cost is USD 500: USD 100 examination plus USD 400 for the first two-year certification term.
- ACAC publishes seven unweighted domains; no percentage weights exist, so do not trust any weighted breakdown.
- Renewal costs USD 400 and requires 40 RCs: 10 for field activity and 30 professional-development hours.
Which CMR This Sheet Covers
This page is a compact review of the Council-certified Microbial Remediator (CMR), issued by the American Council for Accredited Certification (ACAC). Certification decisions are made by ACAC's CMR Certification Board, and Kryterion, Inc. is the testing provider. Other credentials share the same three letters, including unrelated careers and other organizations' mold credentials, so confirm you are working from ACAC material before you memorize anything. If you are still orienting yourself, start with What Is CMR Certification? or What Does CMR Stand For?.
One distinction worth fixing in memory: ACAC administers both CMR and CMRS (the supervisor-level credential), and their eligibility and exam details are kept separate. NORMI also issues a credential it calls Certified Mold Remediator, which is a different, separately issued credential whose syllabus and rules do not define the ACAC exam. Study the ACAC scope, not a lookalike.
Exam Format Snapshot
| Item | Fact |
|---|---|
| Questions | 100 multiple choice, at least four answer choices each |
| Time | Three hours |
| Reference materials | Closed book |
| Passing criterion | 75%, set by the certification board using modified Angoff |
| Delivery | Testing center or online with video proctoring |
| Question and answer order | Randomized |
| Results | Immediate |
Because the passing standard is a criterion set through a modified Angoff process, it reflects what a minimally competent remediator should know rather than a curve against other candidates. For the arithmetic and what 75% means in practice, see CMR Passing Score 2026.
Online Delivery Requirements
- A computer you supply, plus an approved webcam
- A private location for the entire sitting
- A continuous 2 Mbps upload/download connection
Test your setup well before exam day. A connection that dips below the stated speed is a preventable problem, and a testing center is the alternative if your home or office cannot guarantee privacy. Scheduling windows and deadlines are covered in CMR Exam Dates 2026.
Fees and Money Facts
| Cost Item | Amount |
|---|---|
| Initial fee, US/Canada | USD 500 (USD 100 examination + USD 400 certification for first two-year term) |
| Initial fee outside US/Canada | Current official application quotes USD 525 |
| Retake | USD 100 |
| Renewal | USD 400 |
| Non-refundable component | USD 100 processing portion of the certification fee |
Eligibility and Application Mechanics
Two Routes to Qualify
- Experience route: a high-school diploma or GED plus two years of documented microbial-remediation experience.
- Education route: a qualifying two-year postsecondary degree or equivalent 15 qualifying science-related credits, plus at least one year of relevant experience.
Accepted education fields include microbiology, engineering, science, architecture, industrial hygiene and related sciences. A deeper walkthrough is in CMR Requirements 2026.
What You Submit
- Four project sheets documenting your remediation work
- Applicable education transcripts
- The online application
- An electronic affidavit and required email verifications
The handbook also requests employer affidavits. After you sit the examination, the certification board reviews your file, and approval requires a unanimous decision. Passing the exam alone does not finish the process; the review is a separate gate.
The Seven Domains at a Glance
ACAC's examination objectives, from the scope chart approved February 21, 2024, are organized into seven domains. No percentage weights are published. The numbered subdomain columns in the chart are not weights, so any study plan claiming "Domain 4 is 30% of the exam" is inventing a number. Treat all seven as examinable and see CMR Exam Domains 2026 for a fuller tour.
Domain 1: Principles & Equipment
The foundation: how microbial growth behaves and the tools used to control it.
- Why moisture is the root cause driver and what that means for scope decisions
- Containment, air filtration and negative-pressure concepts and when each applies
- Selection and proper use of remediation equipment
Domain 2: Guidelines, Regulations & Standards
Which documents govern the work and what each one actually says.
- Prescribed guidance (EPA, ANSI/IICRC and AIHA texts) and how they relate
- The ACAC Code of Conduct, which sits inside this domain rather than forming its own
- Knowing the edition of a standard you are being asked about
Domain 3: Water Damage
Water events are the usual upstream cause of microbial problems.
- Assessing water-loss conditions and moisture behavior in building materials
- Drying principles and when materials can be dried versus removed
- How the S500 water-damage restoration standard frames decisions
Domain 4: Structural and contents remediation
The hands-on core of the credential: treating buildings and what is inside them.
- Removal and cleaning methods for different materials and contamination levels
- Handling contents, including what can be cleaned and what is disposed of
- Sequencing work so cleaned areas are not recontaminated
Domain 5: HVAC system remediation
Air-handling systems can spread contamination building-wide.
- Recognizing when HVAC components are affected and how they are isolated
- Cleaning and remediation approaches for ducts and equipment
- The role of S520 and related references in this area
Domain 6: Project Documentation & Verification
Proving the work was needed, performed and successful.
- What a defensible project record contains
- How verification of remediation completion is approached
- Why documentation discipline also supports your own application project sheets
Domain 7: Safety
Protecting workers and occupants throughout the job.
- Respiratory protection selection using NIOSH Respirator Selection Logic
- Chemical safety and fall protection, both of which fall under this domain
- Personal protective equipment decisions tied to the hazard present
Prescribed References to Know
The handbook's selected study pages are examples, not exhaustive coverage. It assumes comprehensive knowledge of the prescribed texts, so skimming a summary is not enough. The prescribed references include:
- AIHA, Recognition, Evaluation & Control of Indoor Mold, second edition (2020)
- EPA, Mold Remediation in Schools and Commercial Buildings (2001)
- ANSI/IICRC S500-2021
- S520-2015 with R520-2015, or S520-2024
- NIOSH Respirator Selection Logic (2004)
Pass-Ratio Data: How to Read It
ACAC's 2025 exam pass ratio report shows 31%, or 4 passes from 13 examinations. Read that number carefully:
- The cohort is very small, so one or two outcomes would swing the percentage sharply.
- The report includes retakes and state-licensing-only examinations, so it is not a measure of first-attempt success.
- It cannot tell you your own odds, which depend on your experience, your preparation and your command of the prescribed texts.
For the full context, read CMR Pass Rate 2026: What the Data Shows, and for a realistic sense of difficulty see How Hard Is the CMR Exam?.
Renewal Math
Certification is valid for two years, and renewal costs USD 400. Under the current procedures, renewal requires 40 RCs (renewal credits), allocated as follows:
| Category | Requirement |
|---|---|
| Continued field activity | 10 RCs |
| Professional development | 30 hours |
| Total | 40 RCs |
Keep supporting documentation for everything you claim, because it is requested on audit. Log courses, certificates and field work as they happen rather than reconstructing them in the final month.
Source Conflicts to Be Aware Of
ACAC's own pages do not always agree with one another. None of these change what the credential is, but they affect how you plan your application:
| Topic | Application page | Handbook |
|---|---|---|
| Completion window | Six months | 90 days |
| Verification method | Online/email verification | Retains notarized-paperwork and employer-affidavit instructions |
| Board meeting cadence | Every four to six weeks | Approximately four weeks |
The exact CMR application also uses Florida mold-assessor wording, while the handbook's licensing paragraph mentions CMI. These inconsistencies do not alter this remediation credential or establish that it satisfies any particular license. The handbook is undated, and the February 2024 chart approval date does not by itself prove a new 2026 exam version. When in doubt, ask ACAC and keep a record of the answer.
Domain-Ordered Review Schedule
Since no domain carries a published weight, sequence your review by dependency: the later domains lean on the earlier ones. This is a six-week example you can compress or stretch.
Principles & Equipment, plus Safety basics
- Learn containment and filtration logic first; everything else builds on it
- Start NIOSH Respirator Selection Logic early because it rewards repetition
Guidelines, Regulations & Standards
- Read the EPA and AIHA texts with the Code of Conduct alongside
- Note edition details for S500 and S520
Water Damage
- Work through S500-2021 concepts and moisture behavior
Structural and contents remediation
- Tie material-by-material decisions back to the standards from Week 2
HVAC system remediation, Project Documentation & Verification
- Study S520 for HVAC, then practice describing what a complete project record looks like
Full review and timed practice
- Revisit Safety, then take timed sets under closed-book conditions to build the pacing for 100 questions in three hours
When you are ready to test yourself, use the CMR practice test site for timed sets, and compare your results against the domain list above to find weak areas. Our CMR training overview covers optional course routes.
Quick Answers (FAQ)
The passing criterion is 75%, set by the certification board using a modified Angoff method. The exam has 100 multiple-choice questions and a three-hour limit, and it is closed book.
The initial US/Canada fee is USD 500, made up of USD 100 for the examination and USD 400 for the first two-year certification term. The current official application quotes USD 525 outside the US/Canada. A retake is USD 100, and renewal is USD 400. Optional prep courses and books cost extra.
No. ACAC lists seven examination domains but publishes no percentage weights. The numbered subdomain columns in its chart are not weights, so treat any weighted breakdown you see elsewhere with suspicion.
No. The 2025 figure (4 passes from 13 examinations) covers a very small group and includes retakes and licensing-only examinations. It is not a first-attempt success probability and says nothing about an individual candidate.
No. Passing a licensing-only examination does not confer the CMR designation by itself. Certification requires the full application, including project sheets, affidavit and verifications, and unanimous certification-board review. For the broader value question, see Is the CMR Certification Worth It? and the CMR Salary Guide.