What Is the Tennessee CMC Full Mechanical Contractor Classification?

Tennessee's CMC classification is the state's broad Full Mechanical Contractor classification.

According to the current Prov exam description, a contractor holding full CMC authority may perform qualifying work involving:

• Plumbing systems.
• Gas piping systems.
• HVAC systems.
• Refrigeration systems.
• Process piping.
• Fire sprinkler systems.
• Fire protection systems.
• Boiler systems.
• Fuel gas systems.
• Pollution-control systems.
• Pneumatic tube systems.
• Mechanical insulation.
• Temperature-control systems.

That is a much wider scope than a contractor who only holds CMC-A or CMC-C.

Review the official Tennessee Contractor Classification Outline before deciding which mechanical classification fits your company.

Full CMC vs. CMC-A vs. CMC-C

Broader authority also means broader responsibility. A Full Mechanical license is not simply CMC-C with a few bonus letters attached.

When Is a Tennessee Mechanical Contractor License Required?

Tennessee generally requires a contractor license before contracting for a project costing $25,000 or more.

Contracting can include:

• Bidding.
• Offering to perform the work.
• Negotiating the price.
• Signing the contract.
• Acting as a qualifying construction manager or consultant.

Mechanical subcontractors also generally need the appropriate contractor license when their mechanical portion of a project is $25,000 or more, including labor, materials, and equipment.

Review the Tennessee contractor licensing requirements before bidding.

Step 1: Make Sure Full CMC Matches Your Business Plan

Full CMC is designed for companies that want broad mechanical authority.

It may be a good choice if your company plans to combine several services, such as:

• Commercial plumbing and HVAC.
• Industrial mechanical piping and refrigeration.
• HVAC plus fire sprinkler work.
• Boiler and mechanical equipment installation.
• Process piping and temperature controls.
• Mechanical systems on large commercial and industrial projects.

If your company will perform only HVAC and refrigeration, CMC-C may be enough.

If plumbing and gas piping are your only major trades, CMC-A may be the better fit.

Choosing the smallest classification that covers your real scope can sometimes simplify the exam process. Choosing one that is too small can create a very different kind of problem later.

Step 2: Meet the Full CMC Preapproval Requirement

Full Mechanical CMC is one of only two Tennessee contractor trade examinations currently requiring Board approval before scheduling.

The two are:

• CMC Full Mechanical.
• CMC-A Plumbing.

Tennessee uses a shared Plumbing Exam Pre-Approval Request for both classifications.

The current form asks applicants seeking CMC or CMC-A to verify at least three years of plumbing work experience.

The form also contains an option for applicants with a plumbing or mechanical engineering degree to provide degree documentation in place of the detailed experience pages.

Applicants must currently be at least 18 years old.

This is an important distinction from CMC-C HVAC / Refrigeration, which does not currently have the same special exam-preapproval step.

Step 3: Document Your Plumbing Experience

Because Full CMC includes plumbing authority, the Board's preapproval form specifically asks for plumbing experience verification.

Current documentation options can include:

• Verification from a municipality, county, city, or permit office.
• A copy of an active plumbing license from another government agency.
• W-2 records showing employment with a plumbing contractor.
• Verification from a past plumbing employer or contractor.
• A detailed plumbing work history or resume.
• Qualifying plumbing or mechanical engineering degree documentation.

Useful plumbing experience can include:

• Water piping.
• Gas piping.
• Sewage systems.
• Plumbing fixtures.
• Water heaters.
• Backflow systems.
• Appliance installation.
• Fire-protection-related piping.

Be detailed. "I worked around pipes for a while" is unlikely to become anyone's favorite experience verification.

Step 4: Submit the CMC Preapproval Request

The Tennessee Board currently charges a $50 preapproval fee for CMC and CMC-A exam requests.

Download the CMC / CMC-A Pre-Approval Request from Tennessee's Forms page.

Complete the applicable experience sections, attach the supporting documentation, and follow the current Board submission instructions.

Tennessee's current exam page directs applicants to submit the completed preapproval request to the Board before attempting to schedule with Prov.

Step 5: Choose the Business Entity That Will Hold the License

The Tennessee contractor license is issued to the approved business entity, not simply to the person who passes the test.

The business may be:

• A sole proprietorship.
• A partnership.
• A corporation.
• An LLC.

Corporations, LLCs, and applicable partnerships must be properly registered with the Tennessee Secretary of State.

Use the exact same legal business name on:

• The contractor application.
• Financial statements.
• Surety bond documents.
• General liability insurance.
• Workers' compensation documentation.
• Secretary of State records.

Step 6: Select the Qualifying Agent

Tennessee calls the person who qualifies the company through the required exam a Qualifying Agent, or QA.

The QA may generally be:

• An owner.
• An officer.
• A qualifying full-time employee.

A qualifying individual without the required ownership relationship may need Tennessee's Power of Attorney form.

Tennessee does not require the same individual to take both the trade exam and Business and Law exam. In qualifying situations, different people may serve as the QAs for the different examinations.

Step 7: Schedule the CMC Exam After Approval

Tennessee moved newly scheduled contractor examinations to Prov beginning July 1, 2026.

Full CMC candidates follow a different scheduling path from ordinary self-registration:

1. Submit the Board preapproval request.
2. Provide the required experience or qualifying degree documentation.
3. Pay the current $50 preapproval fee.
4. Receive Board authorization.
5. Follow Prov's scheduling instructions.
6. Pay the $53 trade exam fee.
7. Choose an available test appointment.

Prov currently supports physical testing centers and eligible remote Examroom testing.

Visit Prov's Tennessee Contractor testing page for current scheduling information.

Step 8: Understand the Current CMC Full Mechanical Exam

The current CMC Full Mechanical trade exam has:

• 100 questions.
• 2-hour time limit.
• 73% passing score.
• $53 examination fee per attempt.
• Open-book format.

Two hours for 100 questions gives you an average of about 72 seconds per question.

That is a quick pace for an exam covering this many mechanical systems.

Open book helps, but it does not turn the exam into a leisurely afternoon of reading mechanical codes while sipping coffee.

Step 9: Know the CMC Exam Breakdown

Air Distribution and Vents is currently the largest single section with 18 questions.

Equipment, Refrigerants and Oils, and Sprinkler Systems each contribute another 10 questions.

This is a genuinely broad mechanical exam. Spending all your study time on HVAC while ignoring fire sprinklers, piping, or fuel gas is not a particularly friendly plan for your score.

Step 10: Get the Current CMC Reference Books

Prov currently identifies three primary references for the Full Mechanical examination:

• International Mechanical Code, 2021.
• International Fuel Gas Code, 2021.
• HVAC Basics for Contractors, 4th Edition.

Prov also maintains an Alternate Book List containing previously PSI-approved references that may be used through January 1, 2027.

That transition list includes additional mechanical, plumbing, sprinkler, refrigeration, piping, electrical-reference, ductwork, and safety resources.

For current preparation options, review the Tennessee CMC Full Mechanical Contractor Book Package.

Step 11: Prepare Your Open-Book References Correctly

Prov permits organized references, but there are strict rules.

Current rules allow:

• Highlighting.
• Permanent tabs.
• Underlining in pen before the exam.
• Authorized older or newer editions of the same listed reference.
• A simple four-function calculator.

Current rules prohibit:

• Handwritten notes.
• Moveable or repositionable tabs.
• Post-it notes.
• Loose photocopied pages inserted in books.
• Photocopied reference books unless specifically authorized.
• Unauthorized practice exams.
• Unauthorized study guides inside the testing room.

Your books can be inspected before the exam.

For organized reference preparation, review the Tennessee CMC Full Mechanical Highlighted & Tabbed Book Package.

Step 12: Focus on Air Distribution and Venting

Air Distribution and Vents accounts for 18 questions, the largest subject on the current exam.

Study:

• Supply air.
• Return air.
• Duct construction.
• Duct installation.
• Ventilation.
• Exhaust systems.
• Combustion air.
• Appliance venting.
• Airflow concepts.
• Mechanical code requirements.

Get comfortable moving quickly through the 2021 International Mechanical Code.

Step 13: Study Mechanical Equipment

Equipment currently contributes 10 questions.

Review mechanical equipment such as:

• Furnaces.
• Boilers.
• Air handlers.
• Heat pumps.
• Packaged units.
• Condensing units.
• Refrigeration equipment.
• Mechanical appliances.
• Equipment clearances.
• Installation requirements.

Step 14: Learn Refrigerants and Oils

Refrigerants and Oils contribute another 10 questions.

Important topics can include:

• The refrigeration cycle.
• Refrigerant properties.
• Pressure-temperature relationships.
• Compressors.
• Evaporators.
• Condensers.
• Metering devices.
• Refrigeration oils.
• System charging.
• Recovery and service concepts.

Field experience helps here, but the exam still wants the answer supported by its approved references.

Step 15: Do Not Ignore Sprinkler Systems and Fire Protection

This is one area where Full CMC clearly separates itself from a typical HVAC-only exam.

Sprinkler Systems account for 10 questions, while Fire Protection adds four more.

Review:

• Sprinkler-system concepts.
• Fire-protection piping.
• System components.
• Valves.
• Water-supply concepts.
• Installation principles.
• Mechanical fire and smoke protection.

Fourteen questions is too large a chunk of a 100-question exam to casually donate to the testing computer.

Step 16: Study Fuel Gas Systems

Fuel Gas Systems account for eight questions.

Learn:

• Fuel gas piping.
• Pipe sizing.
• Gas pressure.
• Combustion air.
• Appliance connections.
• Shutoff valves.
• Venting.
• Clearances.
• Installation requirements.

Become comfortable with the 2021 International Fuel Gas Code tables and chapter organization.

Step 17: Study Piping

Piping contributes eight questions.

Full Mechanical contractors may encounter several types of piping, including:

• Mechanical piping.
• Hydronic piping.
• Refrigerant piping.
• Process piping.
• Fuel gas piping.
• Boiler-related piping.

Review materials, supports, sizing concepts, installation practices, expansion, protection, and system-specific requirements.

Step 18: Review Controls and Electrical Concepts

Controls account for four questions and Electrical Concepts add four more.

Study:

• Thermostats.
• Control circuits.
• Relays.
• Transformers.
• Motors.
• Safety controls.
• Electrical fundamentals.
• Mechanical equipment controls.
• Temperature-control systems.

You do not need to turn the mechanical exam into an electrical engineering degree, but eight questions still deserve respect.

Step 19: Practice Load Calculations

Load Calculations account for five questions.

Review factors affecting heating and cooling loads, including:

• Building size.
• Insulation.
• Windows and doors.
• Orientation.
• Outdoor design temperatures.
• Occupancy.
• Internal heat gains.
• Ventilation.
• Infiltration.

Equipment sizing matters because bigger equipment is not automatically better equipment.

Step 20: Study Safety

Safety currently accounts for eight questions.

Mechanical contractors regularly deal with:

• Ladders.
• Scaffolds.
• Fall hazards.
• Electrical hazards.
• Heavy equipment.
• Confined work areas.
• Tools.
• Material handling.
• Excavations.
• Hot work.

Eight questions can move a borderline score a long way in either direction.

Step 21: Practice Under a Timer

The current exam pace is aggressive.

A strong study routine looks something like this:

1. Study one mechanical subject at a time.
2. Answer practice questions without a timer.
3. Look up every incorrect answer.
4. Identify which reference contains the answer.
5. Practice returning to that section quickly.
6. Mix several subjects together.
7. Practice changing between references.
8. Work calculation questions under time pressure.
9. Complete full 100-question simulations within two hours.

For instructor-supported preparation, review the Tennessee CMC Full Mechanical Live Virtual + Self Study Training.

Step 22: Pass Tennessee Business and Law

New Tennessee contractor applicants generally need the separate Tennessee Contractor Business and Law exam.

Current information shows:

• 50 questions.
• 73% passing score.
• $53 examination fee.
• Open-book format.

Prov's June 15, 2026 PDF bulletin lists two hours, while its newer live Tennessee testing information displays 2.5 hours. Candidates should verify the duration shown in their actual scheduling confirmation.

Business and Law includes:

• Business organization.
• Licensing.
• Estimating and bidding.
• Contracts.
• Project management.
• Risk management.
• OSHA safety.
• Financial management.
• Labor law.
• Tax law.
• Lien law.

The current live Prov information lists the NASCLA Contractors Guide to Business, Law and Project Management, Tennessee, 4th Edition.

Step 23: Understand the Retesting Rules

If you do not pass, current Prov rules allow you to retake the examination as many times as necessary.

Current policy provides:

• No mandatory waiting period between failed attempts.
• No fixed maximum number of retakes.
• A new $53 fee for each attempt.

Candidates who have failed at least twice and scored within 10 points of the required 73% may qualify for a formal examination review.

Use the diagnostic report after a failed attempt. Registering again without changing anything is less of a study method and more of a recurring billing plan.

Step 24: Understand Tennessee's Monetary Limit

Every Tennessee contractor license has a classification and a monetary limit.

Full CMC determines what kind of mechanical work the business is authorized to perform.

The monetary limit determines the maximum amount of an individual project or contract the company may generally undertake.

Under Tennessee's traditional financial qualification method, the monetary limit is generally calculated at up to 10 times the lesser of working capital or net worth, together with experience and Board review.

Tennessee also generally allows a 10% monetary-limit tolerance where permitted. The restricted BC-A/r residential classification is the notable exception.

Step 25: Meet the Financial Statement Requirement

Under Tennessee's traditional financial-statement route:

• Requested monetary limits of $3 million or less require a CPA-reviewed or audited financial statement.
• Requested limits above $3 million require a CPA-audited financial statement.
• The financial statement must generally be less than 12 months old.
• The statement must be prepared in the exact legal name and mode of operation being licensed.

To qualify for an Unlimited monetary limit using the traditional financial-statement route, Tennessee currently requires at least $300,000 in working capital and $300,000 in net worth, plus sufficient experience and Board approval.

Step 26: Consider Tennessee's New Surety Bond Option

Beginning July 1, 2026, Tennessee allows contractors to use a qualifying continuous Contractors' Surety Bond as an alternative to submitting the required CPA-reviewed or audited financial statement.

The bond generally must equal at least 50% of the requested monetary limit.

• $500,000 requested monetary limit: at least $250,000 bond.
• $1,500,000 requested limit: at least $750,000 bond.
• $3,000,000 requested limit: at least $1,500,000 bond.
• Unlimited request: current guidance lists a $1,500,000 minimum qualifying bond.

The bond must remain in effect while it is being used as the financial qualification method.

Review the Tennessee Contractor Forms and Financial Resources before deciding which route to use.

Step 27: Obtain General Liability Insurance

Tennessee requires general liability insurance based on the contractor's monetary limit.

• Up to $500,000 monetary limit: at least $100,000 coverage.
• $500,001 through $1,500,000: at least $500,000 coverage.
• $1,500,001 through Unlimited: at least $1,000,000 coverage.

Mechanical contractors working on large commercial and industrial projects may be required by owners or prime contractors to carry significantly higher coverage.

Step 28: Address Workers' Compensation

Tennessee contractor applicants must also provide workers' compensation coverage when required or acceptable exemption documentation.

Depending on the business, this may involve:

• Workers' compensation insurance.
• Construction Services Provider exemption registration.
• Other qualifying exemptions under Tennessee requirements.

Full Mechanical contractors often work on commercial projects with multiple employees and subcontractors, so make sure the insurance arrangement matches what the company actually does.

Step 29: Submit the Tennessee Contractor Application

Passing the exams does not automatically issue your CMC contractor license.

Tennessee currently uses the CORE online licensing system for contractor applications.

The current initial contractor application fee is $250.

The application may require:

• Business entity information.
• Qualifying Agent information.
• CMC examination score.
• Business and Law score.
• Mechanical and plumbing experience.
• Project history.
• Letter of Reference.
• Financial statement or qualifying surety bond.
• General liability insurance.
• Workers' compensation or exemption documentation.
• Secretary of State registration when applicable.
• Required affidavits and disclosures.

Tennessee requires the Letter of Reference to come from a past client, employer, or code official who can speak to your construction experience. A family member cannot provide the reference.

Do Not Bid Until Your License Is Issued

Passing CMC is not the same thing as becoming a licensed contractor.

Before bidding regulated mechanical projects, confirm that your Tennessee license shows:

• The correct legal business name.
• The CMC Full Mechanical classification.
• The correct monetary limit.
• An active license status.

Your score report tells you that you passed the exam. Your license tells customers and regulators that Tennessee approved the business.

Does Tennessee Offer Mechanical Reciprocity?

Tennessee currently has trade-exam waiver agreements with several states for qualifying mechanical classifications.

Current participating states include mechanical or HVAC agreements involving jurisdictions such as:

• Alabama.
• Louisiana.
• Mississippi.
• Ohio.
• South Carolina.
• West Virginia.

The exact classification on your out-of-state license matters.

Tennessee still requires the application, Business and Law requirement when applicable, financial qualification, insurance, business registration, and Board approval.

EPA and Specialty Certifications May Still Apply

A Tennessee Full Mechanical contractor license does not replace every federal or specialty certification that may apply to the work.

For example, technicians performing regulated refrigerant work may need the appropriate EPA Section 608 certification.

Medical gas, fire protection, environmental, local permit, inspection, and other specialized requirements may also apply depending on the project.

Think of Full CMC as very broad mechanical contracting authority, not a magic card that cancels every other regulation in the mechanical universe.

How Long Is the Tennessee CMC License Valid?

Tennessee contractor licenses are generally issued for two years.

The current renewal fee is $200.

Renewal may require:

• Updated financial documentation or qualifying surety bond.
• Current general liability insurance.
• Workers' compensation or exemption documentation.
• Active Secretary of State status when applicable.
• Current disclosures and renewal information.

Tennessee currently charges a $20-per-month late renewal penalty for contractor licenses, up to 12 months.

That renewal window does not give you permission to continue contracting while the license is expired.

Tennessee CMC Full Mechanical Exam Prep Resources

A Simple Tennessee Full CMC Licensing Roadmap

1. Confirm Full CMC matches the mechanical work your company plans to perform.
2. Verify your plumbing experience for the CMC preapproval requirement.
3. Gather W-2s, employer verification, licensing records, or qualifying degree documentation.
4. Submit the CMC preapproval request and current $50 fee.
5. Wait for Board authorization.
6. Choose the business entity that will hold the contractor license.
7. Select the Qualifying Agent.
8. Schedule the approved CMC examination through Prov.
9. Obtain the current approved references.
10. Prepare the books with permitted tabs and highlighting.
11. Study air distribution, equipment, refrigerants, sprinkler systems, fuel gas, piping, controls, and safety.
12. Practice 100 questions within two hours.
13. Pass CMC with at least 73%.
14. Pass Tennessee Business and Law with at least 73%.
15. Select the financial-statement or qualifying surety-bond method.
16. Request a monetary limit supported by your finances and experience.
17. Obtain general liability insurance.
18. Address workers' compensation.
19. Complete Tennessee business registration requirements.
20. Submit the initial contractor application and current $250 fee.
21. Wait for Board approval and license issuance.
22. Verify the Full CMC classification, monetary limit, and active status before contracting.

Helpful Tennessee Full CMC Resources

Frequently Asked Questions

Here are common questions about becoming a Tennessee CMC Full Mechanical Contractor.

Key Takeaways

• Full CMC is Tennessee's broadest mechanical contractor classification. It covers plumbing, HVAC, refrigeration, process piping, boilers, fire protection, sprinkler systems, fuel gas, controls, and other mechanical categories.
• Board preapproval is required before you can schedule the trade exam. Tennessee's current shared CMC/CMC-A form asks for at least three years of plumbing work experience and currently carries a $50 preapproval fee.
• The current CMC exam has 100 questions and a two-hour limit. The passing score is 73%, the fee is $53, and the test is open book.
• Air Distribution and Vents is the largest exam subject. Equipment, refrigerants, sprinkler systems, fuel gas, piping, fire protection, controls, and safety are also important.
• Passing the exams is only part of licensing. The company must also satisfy Tennessee's business, experience, financial, insurance, Qualifying Agent, monetary-limit, and application requirements.

Final Thoughts Before You Start

The Tennessee CMC Full Mechanical Contractor classification is built for contractors who want broad authority across the mechanical trades.

It reaches far beyond ordinary HVAC work. Full CMC can cover plumbing, gas piping, HVAC, refrigeration, process piping, fire sprinklers, fire protection, boilers, pollution control, pneumatic systems, mechanical insulation, and temperature controls.

That broad scope makes it powerful, but it also makes the licensing process more demanding.

Start with the preapproval requirement. Unlike most Tennessee contractor trade exams, Full CMC cannot simply be selected from the scheduler and taken whenever you feel ready. You need Board authorization first.

Tennessee's current preapproval process asks you to demonstrate plumbing experience because plumbing is a major part of the Full Mechanical scope. Get those records organized before you start worrying about practice exams.

Once approved, treat the trade exam like the broad test that it is. Air distribution is important, but so are fuel gas, equipment, refrigeration, piping, sprinklers, fire protection, controls, electrical concepts, calculations, and safety.

Learn your references instead of simply owning them.

The current Prov exam is open book, but 100 questions in two hours means you cannot read chapters from scratch during the test. You need to know which book contains the answer, which chapter is likely to help, and how to reach the correct table or section quickly.

Permanent tabs and highlighting can help. Timed practice helps even more.

Business and Law deserves serious preparation too. Running a full mechanical contracting company means managing contracts, bids, employees, insurance, taxes, liens, project schedules, financial records, and risk in addition to the mechanical systems themselves.

Then comes the licensing application. Tennessee still has to approve the company's business structure, experience, financial qualification, monetary limit, insurance, workers' compensation status, Qualifying Agent, reference, and supporting documents.

If your goal is to build a mechanical company capable of handling several trades under one contractor classification, Full CMC can provide a broad path. Just make sure your experience, exam preparation, financial qualification, and business systems are ready for the responsibility that comes with it.

When you are ready to prepare, explore the Tennessee CMC Full Mechanical Contractor exam prep resources from 1 Exam Prep. Strong mechanical knowledge, organized references, timed practice, and a clear licensing plan can make this very broad exam much easier to manage.