Tennessee licenses mechanical contracting businesses, not individual heating and cooling titles. The CMC-C classification — HVAC, Refrigeration, Gas Piping — is a specialty contractor license issued by the Tennessee Board for Licensing Contractors, held by the business, and earned through examinations passed by the business’s Qualifying Agent. The trade examination is administered by Prov, Inc.: 100 questions in 300 minutes, open book, published at 73% to pass. The PassProfessor program for this credential prepares Qualifying Agents for that sitting and for the Tennessee Contractor Business and Law examination that every first-time licensee must also pass.
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A specialty license, not the whole mechanical field
Begin with what CMC-C is, because its name invites overreading. Under Tennessee’s mechanical contracting classification, styled MC (CMC) in the Board’s rules, the specialty classifications sit beneath the full mechanical license. Classification C is named in the rule exactly as HVAC, Refrigeration, Gas Piping. A license issued in a major classification automatically includes the specialties under it; a license issued in a specialty alone authorises work in that specialty only. CMC-C is therefore a complete credential on its own terms — and a bounded one. It is not the full CMC, whose range runs across the wider mechanical field from plumbing and process piping to boilers, sprinklers, and pollution control. This page keeps that boundary in view throughout.
The bulletin describes the specialty’s scope in practical terms: the installation, alteration, repair, replacement, and servicing of heating, ventilation, air conditioning, refrigeration, gas piping related to HVAC equipment, and associated mechanical systems — including comfort systems, refrigeration equipment, ductwork, exhaust systems, controls, heat pumps, and geothermal and solar thermal HVAC systems. Gas piping belongs here only as it relates to HVAC equipment. The companion guide at /tennessee-cmc-c-hvac-refrigeration-gas-piping-exam-guide/ works through the scope, the outline, and the licensing layers in full.
The examination at a glance
| Item | Verified position |
|---|---|
| Program | Tennessee CMC-C HVAC, Refrigeration & Gas Piping — the examinations its Qualifying Agent must pass |
| Regulator | Tennessee Board for Licensing Contractors (Department of Commerce and Insurance), under T.C.A. Title 62, Chapter 6 |
| Credential holder | The business; the examined individual is the business’s Qualifying Agent |
| Examination vendor | Prov, Inc. — the Board’s examination provider since July 1, 2026 (Candidate Information Bulletin v1.6, effective October 31, 2026) |
| Trade examination | CMC-C: 100 questions / 300 minutes / open book, computer-administered |
| Companion examination | Tennessee Contractor Business and Law: 50 questions / 150 minutes — required of every first-time contractor licensee |
| Tested code | International Mechanical Code 2021 (permanent reference list); see the dated limited-time reference block below |
| Passing standard | 73% to pass — published in that form only |
| Prov examination fee | $53.00 per examination |
| Board fees | Application and initial license $250; renewal $200 per 2 years |
| Pre-approval | Not required for CMC-C before scheduling (the pre-approval requirement attaches to the full CMC and CMC-A, not to this specialty) |
| Administrator note | PassProfessor is independent and is not affiliated with the Tennessee Board for Licensing Contractors |
Two sittings, one standard
A first-time CMC-C applicant’s Qualifying Agent sits two examinations. The CMC-C trade examination carries 100 questions in 300 minutes, open book, delivered by computer. The Tennessee Contractor Business and Law examination carries 50 questions in 150 minutes, also open book, and is required of every first-time contractor licensee — it is not an optional add-on for applicants who feel commercially minded, and a Qualifying Agent who prepares only for air distribution and refrigerants has prepared for part of the route. Its sole reference is the NASCLA Contractors Guide to Business, Law and Project Management — Tennessee, 4th edition, 2024. Each examination is a separate Prov registration at $53.00; no combined price is published, and this page prints none.
Both examinations carry the same passing standard, in the same published form: 73% to pass. That short form is the whole of the published standard. No raw number of questions is printed for these examinations, and none should be worked backwards from the percentage and treated as official.
Where the trade paper’s weight sits
The published CMC-C outline sums to its 100 questions, and its shape tells a candidate how to divide study time. Air Distribution and Venting carries 23 questions — nearly a quarter of the paper, and the single largest block by a wide margin. Piping carries 14. Three blocks carry 10 each: Fuel Gas Systems, HVAC Equipment, and Refrigerants and Oils. General Knowledge carries 9, OSHA Safety 6, HVAC Controls 5, Load Calculations 5, Code Requirements 4, and Electrical Concepts and Fire and Smoke Protection 2 each. A candidate whose preparation treats air distribution as one topic among twelve has misread the examination: duct sizing, air movement, and venting reasoning dominate it, while the refrigeration cycle and fuel gas work each command a tenth of the paper in their own right. The guide sets the outline beside the reference list so the two can be studied together.
The books: a permanent list and a dated one
The CMC-C examination is open book, and the Prov bulletin divides its references into a permanent list and a limited-time block, a distinction that decides what a candidate may bring. The permanent list is headed by the International Mechanical Code 2021, and continues with Modern Refrigeration and Air Conditioning, 21st edition; Refrigeration and Air Conditioning Technology, 9th edition; the Residential Comfort System Installation Standards Manual, 8th edition (SMACNA); OSHA 29 CFR 1926; and HVAC Basics for Contractors, 4th edition. Alongside it, the bulletin carries a block headed as usable for a limited time only, through December 31, 2026, holding references carried over from the prior vendor’s era — among them the International Fuel Gas Code 2021, a Manual J workbook distributed by the proctor at the testing site, the Pipefitters Handbook, the SMACNA HVAC Duct Construction Standards, Ugly’s Electrical References, and the Carrier System Design Manual Part 3 on piping design. From July 1, 2026 through December 31, 2026 a candidate may use a reference the prior vendor recommended for that specific examination; on January 1, 2027 and thereafter, only books recommended by Prov are permitted.
Two disciplines follow. First, preparation should be keyed to the permanent list from the start, because the limited-time block expires on a fixed date. Second, this page states nothing about the fuel gas code’s place in the examination after that date in either direction: the bulletin places the International Fuel Gas Code 2021 inside the limited-time block for CMC-C, and Fuel Gas Systems remains 10 of the 100 published questions. What the next bulletin does with that arrangement is a matter for the next bulletin, and the INTERNAL record in the companion guide notes the point plainly.
Tested and adopted are stated separately, as they should be even when they agree. In the adopted layer, effective August 17, 2025, Tennessee adopted the 2021 editions of the International Mechanical Code and the International Fuel Gas Code among its state codes. The examination’s mechanical code edition therefore matches current state adoption at 2021 — there is no edition gap for a CMC-C candidate to bridge in this cycle — but it is the bulletin’s reference list, not the adoption rule, that governs what may be carried into the sitting. Local editions vary across Tennessee, and no single local edition is asserted statewide here.
Who is examined, and the preference that is not a gate
The license belongs to the business; the Qualifying Agent is the person who must obtain a successful score in the classification. The relationship is defined by business form: for a sole proprietorship, the owner or a full-time employee holding written power of attorney; for a partnership, a general partner or such an employee; for a corporation, a stockholder owning at least 20 percent or such an employee; for a limited liability company, a manager, member, or such an employee. If the person who took the examination leaves the firm, the Board must be notified within 10 days, a replacement must be designated to test within 3 months, and a license left without a Qualifying Agent becomes inactive. A Qualifying Agent for a first-time applicant must pass the trade examination within 90 days.
One sentence in the Board’s application material is routinely hardened into a requirement it does not state. The Board records that it looks at experience — it prefers 3 years — together with equipment and financial information when granting a classification. That is a stated preference, not a fixed minimum-years gate, and this page presents it only as the Board presents it.
CMC-C also differs from its siblings on a point candidates miss: Board pre-approval is not required for CMC-C before scheduling — it attaches to mechanical plumbing, the full CMC and CMC-A. A CMC-C candidate schedules with Prov directly.
What the license authorises: thresholds, limits, and dollars by layer
A Tennessee contractor license is required before bidding or offering a price for projects of $25,000 and up, including materials and labour, and subcontractors performing mechanical or HVAC work must likewise be licensed when their portion reaches $25,000. Every license carries a monetary limitation per classification, printed on the certificate; work beyond it is unlicensed activity as to the excess. The general computation is the lesser of 10 times net worth or 10 times working capital; an unlimited license is discretionary where the applicant demonstrates at least $300,000 in both; a 10 percent tolerance applies; limits across classifications may not be combined, and a project may not be split to avoid a limit. A contractor may bid work in another classification only where its license permits it to perform at least 60 percent of the bid amount. One protection is worth knowing: the CMC notation represents that the holder passed the Board examination, and no county or municipality may require such a licensee or its employees to pass a local test.
Dollars belong to distinct layers. Prov charges $53.00 per examination. At the Board layer, the application and initial license fee is $250 and the renewal fee is $200; the license runs two years, expiring on the last day of the twenty-fourth month. Renewal must be received 30 days before expiration; a late renewal fee grows by 10 percent for each month or fraction of delay, capped at twice the normal fee, and a contractor in default for a full year must apply afresh. General liability minimums at renewal are tiered by monetary limit: $100,000 up to a $500,000 limit, $500,000 up to $1,500,000, and $1,000,000 above that. Since July 1, 2026, a qualifying surety bond of at least 50 percent of the requested limitation may be submitted in lieu of a financial statement — a distinct instrument from the older license bond, and the Board stresses the two forms are not interchangeable.
On continuing education, the position is an absence, stated exactly: Tennessee requires Residential Continuing Education only for the listed residential classifications. No continuing education duty attaches to renewing this mechanical specialty license in the provisions retrieved.
Sitting the examinations
Prov administers the examinations by computer at six Tennessee centres — Chattanooga, Greeneville, Knoxville, Memphis, Murfreesboro, and Nashville — at any Prov centre in the United States, and remotely at home through Examroom.ai. Prov grades the examination immediately on completion and forwards results to the licensing authority. Rescheduling or cancelling is free at least 3 days before the date; missing that deadline or the appointment forfeits the fee. Retakes are permissive: no limit on attempts, a 1-day wait after a failure, and no retake of an examination once passed unless the licensing authority requires it. The application runs online through CORE, with Board-stated processing of four to six weeks. Since September 17, 2026 the Department no longer mails physical certificates; licensees print their license within CORE.
What the PassProfessor program will cover
The CMC-C trade examination as published. Our catalog now includes preparation built on the Prov bulletin’s structure: air distribution and venting at its published weight of 23, piping at 14, fuel gas systems, HVAC equipment, and refrigerants and oils at 10 each, and the controls, load calculation, and code work around them — keyed to the International Mechanical Code 2021 and the permanent reference list. Every item is written from scratch against primary sources.
The Business and Law examination as a required sitting in its own right. The program treats the 50-question Tennessee Contractor Business and Law examination as part of the route, because the Board does.
Independence, stated plainly. PassProfessor is an independent preparation provider, not affiliated with the Tennessee Board for Licensing Contractors, and this program is not a Board course. Completing it confers no license; the Board alone licenses, and examinations are scheduled through Prov. The companion guide at /tennessee-cmc-c-hvac-refrigeration-gas-piping-exam-guide/ carries the fuller account.
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Frequently asked questions
What exactly is CMC-C?
Classification C — HVAC, Refrigeration, Gas Piping — a specialty classification under Tennessee mechanical contracting, issued by the Tennessee Board for Licensing Contractors to a business and earned through its Qualifying Agent’s examinations. A specialty license authorises work in that specialty only; it is not the full CMC.
What examinations must a first-time applicant pass?
Two: the CMC-C trade examination (100 questions, 300 minutes, open book) and the Tennessee Contractor Business and Law examination (50 questions, 150 minutes), each a separate Prov registration at $53.00.
What score passes?
73% to pass — the standard as published, for both examinations. No raw number of questions is published.
Do I need Board approval before booking the CMC-C examination?
No. Pre-approval attaches to the full CMC and CMC-A, not to CMC-C. A Qualifying Agent for a first-time applicant must pass the trade examination within 90 days.
Is three years of experience required?
The Board states that it prefers 3 years and weighs experience together with equipment and financial information when granting a classification. That is a stated preference, not a fixed minimum-years gate.
Which books may I bring, and until when?
The permanent Prov list, headed by the International Mechanical Code 2021. A limited-time block of prior-vendor references is usable only through December 31, 2026; from January 1, 2027, only Prov-recommended books are permitted.
What does it cost, layer by layer?
Prov charges $53.00 per examination. The Board’s application and initial license fee is $250 and renewal is $200 per 2 years. The layers are separate charges and are never a single combined examination price.
If I fail, how soon can I sit again?
Attempts are unlimited, with a 1-day wait after a failure. An examination once passed cannot be retaken unless the licensing authority requires it.
Is PassProfessor affiliated with the Board or Prov?
No. PassProfessor is an independent preparation provider. The Board alone licenses, and Prov administers the examinations.
When does enrollment open for the PassProfessor program?
The program is in the works and enrollment is not yet open. Leave an email address on this page and PassProfessor will write to you when the program is ready — and only about this program.