What Is CIES?

What CIES Actually Is (and Isn't)

CIES stands for Council-certified Indoor Environmental Supervisor. It is a professional certification for people who plan, direct, and take responsibility for remediation work in indoor environments. The word "supervisor" is deliberate: the credential is aimed at practitioners who have already spent years in the field and are now expected to make engineering-control, cleaning, removal, and worker-safety decisions on real projects.

Unlike many entry-level credentials, CIES is not something you earn after a weekend course. You must document actual field experience, submit four project sheets describing work you personally performed, and then pass a three-hour computer-delivered examination. If you are searching for the plain-language definition, our short explainers on what CIES stands for and the meaning of CIES cover the vocabulary, while this article goes deeper into how the credential works in practice.

Who Issues It and Why That Matters

The credential is issued by the American Council for Accredited Certification (ACAC) through its CIES Certification Board. ACAC's program carries accreditation from the Council for Engineering and Scientific Specialty Boards (CESB). That accreditation matters because it signals that the certification process, including exam development, has been reviewed against recognized specialty-certification standards. The passing score, for example, is established with a Modified Angoff method, a standard-setting approach in which subject-matter experts judge how a minimally competent candidate would perform on each item.

The examination itself is delivered through Kryterion, Inc. ACAC does not develop or administer preparation courses, and no mandatory training course or minimum training-hour requirement is published for CIES. In practice, that means the burden of preparing falls on you, and your best primary source is ACAC's own candidate handbook and its listed references. For a structured approach, see our CIES study guide.

The Five Competency Areas

ACAC's handbook publishes five competency headings for CIES. They are unweighted: no public chart assigns percentages to them, and the handbook notes only that the board prescribes an exam blueprint. Treat the five headings as preparation topics rather than a guaranteed map of every exam item. Each one is framed the same way, "understand and execute successful remediation," and each addresses engineering controls, cleaning and removal methods, worker safety, and applicable regulations. For an expanded walkthrough, read our complete guide to the CIES exam domains.

How You Qualify: Degrees, Years, and Project Sheets

CIES eligibility combines education and documented field time. There are three published pathways:

• Four-year path: a related four-year postsecondary degree or 30 qualifying college credits, plus four years of documented indoor environmental remediation experience.
• Two-year path: a related two-year degree or 15 qualifying credits, plus six years of experience.
• Experience-heavy path: a high school diploma or GED plus eight years of experience.

Your experience must span at least three of five areas: asbestos, lead, hazardous materials, microbial/allergens, and industrial hygiene/chemicals/toxicology. ACAC's FAQ explains which semester-credit subjects qualify and stresses that experience must be actual field work. For a deeper breakdown, see CIES requirements and how to qualify.

The four project sheets

Every applicant submits four project sheets. ACAC describes each sheet in three parts: the problem, your own responsibilities and actions, and the outcome. The phrase "your own" is the crux. Reviewers want to see what you personally decided and did, not what your company or crew did around you. Applicants who write vague team summaries tend to create unnecessary friction with the board. Choose projects that show your hands-on supervisory judgment, and ideally spread them across the disciplines that satisfy your three-of-five requirement.

Application timeline: a known discrepancy

The current ACAC application page describes online submission, required email verifications, a six-month window that includes the examination, and unanimous board approval, with the board meeting every four to six weeks. The candidate handbook, however, gives a 90-day window and describes notarized forms and employer affidavits. ACAC has not reconciled these two descriptions publicly. Before you begin, confirm the current process directly with ACAC rather than relying on either document alone.

Exam Format and Test-Day Mechanics

The handbook describes a fixed question set with randomized item and answer order, and adaptive testing is not described. Because the exam is closed book, you cannot look up an exposure limit or a regulatory citation during the test. That shapes preparation: you need working fluency with the regulations and procedures, not just awareness of where to find them. Our breakdown of the CIES passing score explains what 75% means across a 120-question exam.

Logistics to plan around

• Testing center: bring two government-issued IDs, including one with a photo. The current Examinations page asks for arrival 15 minutes early, while the handbook says 30 minutes. Plan for the longer window.
• Online delivery: you supply the computer, an approved webcam, and a private location. ACAC specifies at least 2 Mbps upload and download speeds, and phones and tablets are not allowed.
• Calculator policy: permission could not be verified, so confirm with ACAC before test day instead of assuming either way.

Scheduling windows and deadlines are covered in CIES exam dates and scheduling.

Fees, Term Length, and Renewal

No separate member and non-member fee schedule is published. The full pricing picture, including what to budget beyond ACAC's fees, is in our CIES certification cost breakdown.

Staying certified

Certification lasts two years. ACAC's current recertification procedures call for 40 recertification credits during the term: 10 for continued field activity and 30 for professional development. You attest to your credits and keep evidence in case of audit, and ACAC requests a current photo. Be aware that other ACAC materials describe the requirement differently: the handbook gives a general 40-credit figure, and the program page mentions 20 professional-development hours annually. The recertification procedures page is the most current statement, but verify before you start logging hours.

CIES vs. State Licensing

This is the single most misunderstood point about the credential. State licensing eligibility and ACAC certification eligibility are two separate things. A licensing-only exam result does not itself confer CIES certification.

Florida is the usual example. Indexed content from the Florida Department of Business and Professional Regulation lists CIES among the examinations associated with mold-related services licensing, though the regulator's page returned an access error when we attempted a fresh direct retrieval, so we cannot present that listing as freshly verified. More importantly, the regulator's accessible checklist for the Mold Remediator initial license by examination shows that passing an approved exam is only one part of licensing. Separate application, education and experience, fingerprinting, and insurance requirements also apply.

CIES Compared With Related ACAC Credentials

People often ask how CIES differs from other ACAC indoor-environment credentials, particularly the mold-focused CMRS and the CIER. The deciding factor is scope: CIES spans five remediation disciplines and requires experience across at least three, while CMRS is centered on mold remediation. Check ACAC's pages for each credential's current experience requirements before choosing, since they differ in prerequisites and exam content.

If you are weighing options, our analysis of whether CIES certification is worth it walks through the decision in more detail.

Who Uses the Credential

The natural audience is remediation supervisors, project managers, and field leads at abatement and remediation contractors, along with consultants and environmental health and safety staff who oversee or review remediation work. Because the credential is framed around supervising successful remediation, employers and clients can treat it as evidence that a person understands controls, methods, worker safety, and regulations across several hazard types rather than a single trade. For a look at the roles that value it, see CIES jobs.

Pay is a harder question. We have not verified a reliable salary survey specific to ACAC CIES holders, and there is no verified causal earnings premium attached to the credential. Treat any specific salary claim you encounter with skepticism, and read our CIES salary guide for how to evaluate earnings qualitatively.

Sequencing Your Preparation

Because the exam is closed book and spans five hazard areas, the most useful planning question is not "how many hours?" but "which domain will cost me the most to learn?" Start with your weakest of the five, since your own field experience likely already covers one or two. A candidate whose work is mostly asbestos abatement, for example, should front-load chemicals and microbial content rather than rereading familiar asbestos rules.

Adjust the length to your experience. For realistic timed practice, use the CIES practice tests, and keep our CIES cheat sheet handy for last-week review. If you are wondering how demanding the exam is relative to your background, read how hard the CIES exam is.

A note on pass rates

Do not lean on published pass-rate numbers to calibrate your confidence. No numerical 2025 or 2026 CIES pass rate was verified: ACAC's 2025 activity report shows dashes for CIES applicants and pass ratio, and CIES is omitted from the 2025 exam pass ratio report. A dash does not mean a 0% pass rate. Historical 2024 figures conflict with each other and involve only two candidates. Our CIES pass rate analysis explains why these numbers should not drive your decisions.

Frequently Asked Questions

CIES rewards candidates who have genuinely supervised remediation work and can reason across multiple hazard types without notes. If that describes your background, the path is clear: document your experience carefully, study the regulations behind each of the five competency areas, and confirm every process detail with ACAC before you pay or schedule.