What Is the Tennessee CMC-A Classification?

Tennessee places CMC-A under its Mechanical Contracting family of classifications.

The official description is:

The classification can involve the installation, alteration, repair, and maintenance of plumbing systems serving residential, commercial, and industrial occupancies.

Work may include:

• Water supply systems.
• Water distribution piping.
• Sanitary drainage.
• Drain, waste, and vent systems.
• Storm drainage.
• Plumbing fixtures.
• Water heaters.
• Traps and cleanouts.
• Backflow prevention.
• Plumbing piping materials.
• Fuel gas piping related to plumbing systems.
• Gas appliances and related piping.

CMC-A does not automatically provide every mechanical classification available in Tennessee. HVAC, fire sprinklers, process piping, boiler work, and other mechanical categories have their own classifications or requirements.

CMC-A vs. Full CMC Mechanical

If your business is focused mainly on plumbing and related gas piping, CMC-A may be the better fit.

If you also plan to perform HVAC, refrigeration, process piping, boilers, and other mechanical work, compare CMC-A with the full CMC classification before registering.

Picking the correct exam now is cheaper than discovering later that your business plan has more mechanical systems than your license does.

CMC-A vs. Tennessee Limited Licensed Plumber

Tennessee also offers a Limited Licensed Plumber, or LLP, credential.

Tennessee currently says the LLP credential is required only in municipalities using the Division of Fire Prevention for permits or inspections. Local jurisdictions may instead use their own plumbing licensing requirements.

Review the Tennessee Limited Licensed Plumber information if you are deciding between LLP and CMC-A.

When Is the CMC-A Contractor License Required?

Tennessee generally requires the appropriate contractor license before bidding, offering, negotiating, or contracting for projects of $25,000 or more.

Mechanical and plumbing subcontractors contracting directly with another contractor generally need the contractor license when their portion of the project reaches $25,000 or more.

The amount includes:

• Labor.
• Materials.
• Equipment.

The contractor license needs to be in place before regulated bidding or contracting activity.

Step 1: Meet the Special CMC-A Experience Requirement

CMC-A is unusual because Tennessee requires experience approval before the trade exam can be scheduled.

Current Prov and Tennessee guidance requires the candidate to demonstrate:

• At least three years of plumbing experience, or
• A degree in plumbing or mechanical engineering.

This is more specific than the general experience review used for many other Tennessee contractor classifications.

Plumbing experience may involve:

• Water piping.
• Sanitary drainage.
• Vent systems.
• Fixtures.
• Water heaters.
• Backflow systems.
• Sewage systems.
• Gas piping.
• Commercial plumbing.
• Residential plumbing.
• Industrial plumbing.

Step 2: Apply for CMC-A Exam Preapproval

Before registering with Prov, complete Tennessee's Plumbing Exam Pre-Approval Request.

Current Tennessee instructions require you to provide documentation supporting the three-year plumbing experience requirement or qualifying degree.

Depending on your situation, supporting documents may include:

• Experience verification completed by an employer or plumbing contractor.
• Verification from a municipality, county, or licensing agency.
• Copies of qualifying W-2 records.
• A copy of an active plumbing license from another government agency.
• Documentation of a qualifying plumbing or mechanical engineering degree.

The current preapproval fee is $50.

The completed request is submitted to the Tennessee Board for Licensing Contractors. Once the Board approves you, Prov provides instructions for scheduling the examination.

Visit the Tennessee Contractor Exam Information page for current preapproval instructions.

Step 3: Choose the Business That Will Hold the License

The Tennessee contractor license is issued to the approved business entity.

That may be:

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

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

Keep your exact legal business name consistent on your application, insurance, financial documents, surety bond if used, and Secretary of State records.

Step 4: Select the Qualifying Agent

Tennessee calls the individual who qualifies the business for an examination the Qualifying Agent, or QA.

The QA can generally be:

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

A QA without ownership may need to complete Tennessee's Power of Attorney form.

Tennessee also allows the trade exam and Business and Law exam to be taken by different qualifying individuals in qualifying situations.

Step 5: Schedule the CMC-A Exam Through Prov

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

CMC-A candidates cannot simply self-register first.

1. Complete the Tennessee CMC-A preapproval request.
2. Submit the required experience or degree documentation.
3. Pay the current $50 preapproval fee.
4. Receive Board approval.
5. Follow Prov's scheduling instructions.
6. Pay the Prov trade exam fee.
7. Select your testing date and location or eligible remote option.

Prov currently offers physical testing locations as well as remote Examroom testing for eligible candidates.

Step 6: Understand the Current CMC-A Exam

The current Prov Candidate Information Bulletin lists:

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

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

That is a fast exam.

You need plumbing knowledge, calculation skills, and enough familiarity with the books to locate code provisions without starting a small archaeological expedition every time you open the index.

Step 7: Know the Current CMC-A Exam Breakdown

Drain, Waste, and Vent Systems is the largest section with 20 questions.

Isometrics is next with 18 questions.

Add Code Requirements, Fuel Gas Systems, and Water Supply and Distribution, and those five subjects account for 68 of the 100 questions.

Step 8: Get the Current CMC-A Exam Books

The current Prov bulletin lists:

• International Plumbing Code, 2021.
• Mathematics for Plumbers and Pipefitters, 8th Edition.
• Plumbing Basics for Contractors, 4th Edition, 2021.
• International Fuel Gas Code, 2018 or 2021 edition.
• OSHA 29 CFR Part 1926.

Prov currently allows certain previously approved PSI references during the transition period through January 1, 2027.

Candidates who want the main references together can review the Tennessee CMC-A Mechanical Plumbing Book Package from 1 Exam Prep.

Step 9: Prepare Your Open-Book References

Open book helps only when the books are organized and familiar.

Current Prov rules allow approved preparation methods such as highlighting and permanent tabs, subject to the testing-provider rules.

Candidates should avoid:

• Handwritten notes.
• Loose inserted pages.
• Moveable or repositionable tabs.
• Post-it notes.
• Unauthorized practice material.
• Photocopied reference books.

Books may be inspected before testing.

For prepared references, review the Tennessee CMC-A Highlighted & Tabbed Book Package.

Step 10: Focus on Drain, Waste, and Vent Systems

Drain, Waste, and Vent Systems account for 20 questions, making this the biggest single exam section.

Study:

• Sanitary drainage sizing.
• Drainage fixture units.
• Horizontal drainage.
• Vertical stacks.
• Vent sizing.
• Vent connections.
• Traps.
• Cleanouts.
• Indirect waste.
• Special waste.

Become comfortable locating the right IPC tables quickly.

Step 11: Practice Plumbing Isometrics

Isometrics account for 18 questions, making them one of the most important parts of CMC-A preparation.

Practice reading and analyzing:

• Vertical piping.
• Horizontal branches.
• Fixture connections.
• Vent layouts.
• Drainage arrangements.
• Pipe sizing.
• Changes in direction.
• Building drain and stack relationships.

Isometric questions can punish a rushed reader. Follow the piping carefully before deciding where anything goes.

Step 12: Study Water Supply and Distribution

Water Supply and Distribution accounts for 10 questions.

Review:

• Water service sizing.
• Water distribution piping.
• Pressure requirements.
• Fixture units.
• Backflow prevention.
• Valves.
• Materials.
• Hot and cold water distribution.

Learn the tables and understand how pressure, developed length, and fixture demand affect sizing.

Step 13: Study Fuel Gas Systems

Fuel Gas Systems account for another 10 questions.

Important areas include:

• Gas pipe sizing.
• Gas pressure.
• Appliance connections.
• Shutoff valves.
• Combustion air.
• Venting.
• Installation clearances.
• Gas piping materials.

Learn where the fuel-gas sizing tables are and practice selecting the correct table before doing the calculation.

Step 14: Practice Plumbing Math

Plumbing Math has six dedicated questions, but calculation skills can also appear inside other subjects.

Practice:

• Fractions and decimals.
• Area and volume.
• Pipe offsets.
• Angles.
• Grade and slope.
• Unit conversions.
• Measurements.
• Pipe lengths.

Work enough calculations that the math feels routine. Test day is a poor time to rediscover fractions.

Step 15: Study OSHA Safety

OSHA contributes four questions.

Review:

• Excavations.
• Ladders.
• Scaffolds.
• Personal protective equipment.
• Power tools.
• Material handling.
• General construction hazards.

Four questions may look small, but four points can become very interesting when your score is sitting near 73%.

Step 16: Use Timed Practice

The current format is fast enough that timed practice should be part of your study plan.

1. Study one plumbing topic at a time.
2. Answer practice questions without rushing.
3. Look up every missed answer.
4. Identify the correct reference and table.
5. Repeat the lookup until it becomes faster.
6. Practice isometric questions.
7. Mix IPC, fuel gas, math, and OSHA questions.
8. Complete full timed simulations.

For structured preparation, review the Tennessee CMC-A Mechanical Plumbing Contractor Online Exam Prep Course.

Step 17: Pass Tennessee Business and Law

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

Current exam information lists:

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

The June 2026 Prov bulletin lists two hours. Because online testing information can be updated during the provider transition, verify the duration shown when you schedule.

Business and Law covers:

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

Plumbing gets water where it belongs. Business and Law helps make sure the money also goes where it belongs.

Step 18: Understand Your Monetary Limit

Every Tennessee contractor license has an approved monetary limit.

CMC-A determines the type of work the business may perform. The monetary limit determines the maximum size of an individual project or contract the business may generally undertake.

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

Step 19: Meet the Financial Requirements

Tennessee requires financial qualification before issuing the contractor license.

Under the traditional financial-statement route:

• Requested monetary limits of $3 million or less generally require a CPA-reviewed or audited financial statement.
• Requested limits above $3 million generally require a CPA-audited financial statement.
• The statement must be prepared for the correct applicant business.
• Experience must also support the requested limit.

Contractors seeking an Unlimited limit through the financial-statement route generally need at least $300,000 in working capital and $300,000 in net worth, an audited financial statement, sufficient experience, and Board approval.

Step 20: Consider the 2026 Surety Bond Option

Beginning July 1, 2026, Tennessee allows a qualifying continuous Contractors' Surety Bond to be used instead of the required financial statement when all applicable requirements are satisfied.

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

Examples:

• $500,000 requested limit: at least $250,000 bond.
• $1,000,000 requested limit: at least $500,000 bond.
• $1,500,000 requested limit: at least $750,000 bond.
• $3,000,000 requested limit: at least $1,500,000 bond.

Review the Tennessee Contractor Forms and Financial Resources before selecting your financial qualification method.

Step 21: 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.
• More than $1,500,000 through Unlimited: at least $1,000,000 coverage.

Customers, general contractors, property owners, and commercial projects may require higher limits than Tennessee's minimum licensing requirement.

Step 22: Handle Workers' Compensation

Contractor applicants must also address Tennessee workers' compensation requirements.

Depending on the business structure and available exemptions, that may involve:

• Workers' compensation insurance.
• A qualifying Construction Services Provider exemption.
• Other documentation accepted under Tennessee requirements.

Make sure the coverage or exemption matches your actual business arrangement.

Step 23: Submit the Tennessee Contractor Application

Passing the examinations does not automatically issue the contractor license.

Tennessee currently uses the CORE licensing system for contractor applications.

The current initial contractor application fee is $250.

Your application may include:

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

Passing the Exams Does Not Mean You Are Licensed

Even after passing CMC-A and Business and Law, you still have to receive approval from the Tennessee Board.

Before bidding regulated plumbing work, verify that your contractor license shows:

• The correct legal business name.
• The CMC-A classification.
• The correct monetary limit.
• An active status.

A passing test score is excellent news. It is still not a contractor license.

Does Tennessee Offer Plumbing Reciprocity?

Tennessee has trade-exam waiver agreements with certain states and classifications.

Current Tennessee information includes qualifying plumbing or mechanical agreements with states such as:

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

The exact classification on your existing license matters.

Medical Gas Work Is a Separate Issue

Tennessee separately regulates medical gas piping.

Do not assume that a CMC-A Plumbing and Gas Piping classification automatically satisfies every certification or licensing requirement related to medical gas systems.

Contractors planning to perform medical gas installations should verify the additional Tennessee requirements that apply to that work.

How Long Is the Tennessee CMC-A License Valid?

Tennessee contractor licenses generally renew on a two-year cycle.

The current contractor renewal fee is $200.

Renewal may require:

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

Tennessee currently allows a 12-month contractor renewal grace period with a $20 monthly late penalty, but an expired license should not be treated as permission to continue regulated contracting.

Tennessee CMC-A Exam Prep Resources

A Simple Tennessee CMC-A Licensing Roadmap

1. Confirm CMC-A Plumbing and Gas Piping matches your business goals.
2. Document at least three years of plumbing experience or a qualifying degree.
3. Submit the Tennessee Plumbing Exam Pre-Approval Request.
4. Pay the current $50 preapproval fee.
5. Wait for Board authorization before scheduling CMC-A.
6. Select the business entity that will hold the license.
7. Identify the Qualifying Agent.
8. Schedule the approved CMC-A exam through Prov.
9. Obtain the current authorized reference books.
10. Prepare the references according to Prov rules.
11. Study DWV systems and isometrics heavily.
12. Study plumbing code, fuel gas, water supply, math, and OSHA.
13. Practice completing 100 questions within two hours.
14. Pass CMC-A with at least 73%.
15. Pass Tennessee Business and Law with at least 73%.
16. Choose the appropriate financial qualification method.
17. Obtain general liability insurance.
18. Address workers' compensation requirements.
19. Submit the contractor application and current $250 fee.
20. Wait for Tennessee Board approval.
21. Verify the CMC-A classification, monetary limit, and active status before contracting.
22. Maintain the license and renew it every two years.

Helpful Tennessee CMC-A Resources

Frequently Asked Questions

Key Takeaways

• CMC-A is Tennessee's Plumbing and Gas Piping contractor classification. It is intended for qualifying contractor-level plumbing and related gas piping work.
• CMC-A requires Board preapproval before the trade exam. Candidates currently need at least three years of plumbing experience or a qualifying plumbing or mechanical engineering degree, plus the $50 preapproval fee.
• The current Prov exam has 100 questions and a two-hour limit. It is open book, costs $53 per attempt, and requires 73% to pass.
• DWV systems and isometrics dominate the examination. Together they currently account for 38 of the 100 questions.
• Passing the exams is only part of licensing. Applicants must also satisfy Tennessee's financial, insurance, business, experience, Qualifying Agent, application, and monetary-limit requirements.

Final Thoughts Before You Start

Becoming a Tennessee CMC-A Mechanical Plumbing Contractor takes more than passing a plumbing test.

This classification is designed for contractors who are ready to move into larger plumbing and gas piping projects. That means Tennessee wants to see real plumbing experience before it even allows you to schedule the trade examination.

Start with that preapproval requirement. Gather your experience records, W-2s, licensing documents, employer verification, or qualifying degree documentation before trying to schedule with Prov.

Once approved, take the exam preparation seriously.

The current Prov CMC-A examination gives you 100 questions in two hours. Drain, Waste, and Vent Systems and isometrics make up 38% of the exam by themselves. Fuel gas, water distribution, and code requirements add another 30 questions.

Learn the International Plumbing Code well. Know how to find drainage and vent tables, fixture requirements, water distribution rules, and sizing information quickly. Practice isometric drawings until tracing a piping system feels normal instead of like solving a maze drawn by a plumber with a sense of humor.

Spend time in the International Fuel Gas Code too. Gas pipe sizing, venting, combustion air, shutoffs, appliances, and installation requirements are important parts of the test.

Do not forget plumbing math. Calculations involving slopes, offsets, measurements, pipe lengths, and conversions become much easier when you practice them before the clock starts.

Business and Law also matters. Once you become a contractor, your job includes more than piping systems. You also need to understand contracts, bidding, liens, project management, financial management, licensing rules, taxes, labor requirements, and risk.

After you pass the exams, complete the licensing application carefully. Tennessee still needs to approve the business entity, Qualifying Agent, financial qualification, monetary limit, insurance, workers' compensation information, experience, reference, and supporting documents.

Also remember the 2026 exam-provider change. Older CMC-A information may still show 110 questions and 4.5 hours. The current Prov bulletin uses a 100-question, two-hour format, so always check the latest official information before testing.

When you are ready to organize your preparation, explore the Tennessee CMC-A Mechanical Plumbing Contractor exam prep resources from 1 Exam Prep. The right books, strong code navigation, timed practice, and a clear understanding of Tennessee's preapproval and licensing process can make the path to becoming a licensed mechanical plumbing contractor much easier to manage.