Licensed plumbing contractor installing supply and drain piping

Become a Licensed C-36 Plumbing Contractor

The C-36 Plumbing classification is one of California's steadiest, highest-volume trades, water supply, drainage, gas piping, and water heating in every home and building. The ADU boom keeps demand strong.

View Exam Prep Programs

Requirements

Minimum age: 18+ is CSLB's normal applicant path. A minor may qualify only after a court appoints a guardian (BPC §7065.5)
Experience required: 4 full-time-equivalent years of journey-level experience within the past 10 years; CSLB prorates part-time work
Contractor bond: $25,000

About the Exam

Exam format: 2 parts (Law & Business + Trade)
Law & Business exam: 115 questions
School-observed scores: 65% Law / 66% Trade; not published as fixed by CSLB
Application fee: $450

License renews every 2 years. Governing code: CCR §832.36

About this classification

What does a C-36 Plumbing contractor do?

A C-36 Plumbing Contractor provides a means for a supply of safe water and the proper disposal of fluid waste in all structures and fixed works, the supply, drainage, venting, gas piping, and water-heating systems a building relies on. (Per California Code of Regulations, Title 16, §832.36.)

The C-36 scope is broad. California requires a C-36 contractor for water supply and waste-disposal systems, gas piping from the utility meter to gas appliances, water and gas piping from the meter to the structure, fluid heating including solar, and health-and-safety devices such as backflow preventers and water-conditioning equipment. The one notable carve-out: forced warm-air heating units fall under the C-20, not the C-36.

Official source: CSLB C-36 classification · CSLB fee schedule Last reviewed: March 2026

Scope of work

New-construction rough-in, supply, drain, waste, and vent piping
Gas piping from the meter to gas appliances and connections
Tank and tankless water heater installation and replacement
Fixture installation, sinks, toilets, tubs, showers
Sewer and water service line repair and replacement
On-site sewage and fluid-waste disposal connections
Backflow preventers, regulating valves, and gas earthquake valves
Medical, dental, and compressed-air gas piping
Venting and piping for gases and liquids
Solar and standard water/fluid heating systems

High-demand specialties

ADU & Repipe, Accessory-dwelling-unit construction drives steady new plumbing work
Tankless Water Heaters, High-efficiency upgrades are a growing service line
Medical Gas Systems, A specialized, well-paid niche (absorbed former D-23)
Repipe & Service, Aging housing stock means a constant repair pipeline

Important notes

A C-36 contractor can install gas piping to a furnace, but cannot install the forced warm-air furnace and ductwork itself, that work needs a C-20 (HVAC) license.
The C-36 covers full plumbing systems; a contractor who only hooks up water-conditioning equipment to existing lines needs just a C-55, not a C-36.
Boilers, hydronic (hot-water) heating, and steam fitting fall under the C-4, the C-36 handles supply, drainage, gas, and standard water heating.
Any plumbing project over $1,000 (labor and materials combined) requires a licensed contractor. California also requires workers' compensation coverage for licensees.

The CSLB exam

What's on the C-36 Plumbing exam?

California requires you to pass a two-part CSLB exam: the Law & Business exam (the same for every classification) and the C-36 Plumbing trade exam. CSLS has observed scores of 65% for Law & Business and 66% for the C-36 trade exam. CSLB does not publish fixed passing scores and may vary them by exam version.

Law & Business

Same for all classifications

115 questions, multiple choice, computer-based
3.5 hours allotted
Topics: California contractor law, business management, safety, estimating, project management

C-36 Trade Exam

Plumbing-specific

about 115 questions, multiple choice, computer-based
3.5 hours allotted
Topics: water supply and distribution, drainage, waste and vent systems, gas piping, fixtures and appliances, plumbing code, isometric drawings

How to Get Your C-36 Plumbing License

Step 1

Qualify

18+ is CSLB's normal applicant path. A minor may qualify only after a court appoints a guardian (BPC §7065.5). You also need a valid SSN/ITIN and 4 full-time-equivalent years of journey-level plumbing experience within the past 10 years; CSLB prorates part-time work. Up to 3 years may be substituted with approved education or apprenticeship.

Step 2

Apply to CSLB

Submit your application, get fingerprinted, and pay the $450 application fee. Processing times vary; check the CSLB's current processing times.

Step 3

Study & Prepare

Prepare for both exam parts, on your own or with a CSLS exam prep program. 99% of CSLS students pass on their first try, backed by our 100% Money-Back Guarantee.

Compare programs

Step 4

Pass the Exam

Two parts: Law & Business (115q, 3.5 hrs) + C-36 Trade. Multiple choice, computer-based. CSLS has observed scores of 65% Law & Business / 66% C-36 Trade; CSLB does not publish fixed passing scores and may vary them by exam version.

Step 5

Get Licensed

Post your $25,000 contractor bond, pay the $200 license fee, and receive your C-36 license. You're officially in business.

Step 1

Qualify

Step 2

Apply to CSLB

Submit your application, get fingerprinted, and pay the $450 application fee. Processing times vary; check the CSLB's current processing times.

Step 3

Study & Prepare

Prepare for both exam parts, on your own or with a CSLS exam prep program. 99% of CSLS students pass on their first try, backed by our 100% Money-Back Guarantee.

Compare programs

Step 4

Pass the Exam

Step 5

Get Licensed

Post your $25,000 contractor bond, pay the $200 license fee, and receive your C-36 license. You're officially in business.

Career outlook

Why get your C-36 Plumbing license?

$75,300

Mean CA Wage (BLS)

$147K

San Jose Area Mean

$70K–$150K+

Owner Income Range

99%

CSLS First-Time Pass Rate

Steady, recession-resistant demand

Plumbing is one of the most stable trades in California. Every home and building needs water supply, drainage, and gas systems, and they all eventually need repair. The statewide push to build accessory dwelling units (ADUs) has added a fresh pipeline of new-construction plumbing work on top of the constant repair-and-replace demand from aging housing stock.

Specialize and earn more

The C-36 scope is wide enough to build a niche around. Medical-gas piping, tankless water-heater conversions, repipes, and backflow testing all command premium rates. Many plumbers pair the C-36 with a C-20 or C-34 to widen the kinds of jobs they can bid.

Premium earning potential

California plumbers earn a mean wage of $75,300 (BLS), and pay climbs sharply in high-cost metros, the San Jose area averages roughly $147,087. Licensed C-36 contractors running their own businesses commonly earn $70,000 to $150,000 or more. The license is legally required for jobs over $1,000, which keeps unlicensed competition out of larger contracts.

C-36 vs. C-20: know the boundary

The dividing line is the appliance. A C-36 runs the gas piping to a furnace; the C-20 (HVAC) installs the forced warm-air furnace, ducts, registers, and thermostats. If your work is supply, drain, gas, and water heating, the C-36 is your license, but you cannot self-perform the warm-air heating system itself.

Wage data: U.S. Bureau of Labor Statistics (OES) and California EDD.

Exam Prep Programs

Compare C-36 Plumbing Exam Prep Programs

Every program prepares you for the required CSLB exam for C-36 Plumbing. Our 99% first-time pass rate is backed by the 100% Money-Back Guarantee on eligible programs.

Feature-by-feature comparison of all four CSLS exam prep programs
Features	Most Popular All-Inclusive C-36 Plumbing $1,195.00 Value: $2,500	Live Online C-36 Plumbing $695.00 Value: $995	Crash Course C-36 Plumbing $495.00 Value: $695	Home Study C-36 Plumbing $295.00 Value: $395
Best For	Comprehensive prep with maximum support	Remote learners wanting live instruction	Experienced pros with an exam date soon	Self-directed independent learners
Law & Business Classes	4 Classes + Full-Day Review	4 Live Online + Review	Full-Day Review Only	Not included
Trade Math Training	30-Day Interactive + Review	Online Video Review	14-Day Crash Course	Not included
Test-Taking Skills Seminar	1-Day In-Person	1-Day Online	Not included	Not included
Law & Business Materials	Online; binder add-on available	Online; binder add-on available	Online; binder add-on available	Online; binder add-on available
Trade-Specific Materials	Online; binder add-on available	Online; binder add-on available	Online; binder add-on available	Online; binder add-on available
Study Materials	Full Online Suite	Online Materials + Audio/Video	Online + Audio/Video	Online + Audio
Online Videos	Full Suite: L&B, Trade, H&S, Math	Audio + H&S + Math Videos	Audio + H&S + Math Videos	L&B Audio + H&S Video
Law & Business Practice Exams	6 Months	2 Months	30 Days	30 Days
Trade Practice Exams	6 Months	2 Months	30 Days	30 Days
School Location Access	25+ Locations	25+ Locations	25+ Locations	Self-Study Only
Application Assistance	Preparation & Review	Review Only	Review Only	Not included
Money-Back Guarantee	Included	Included	Included	Not included
Bond Fee Discount	50% off first-year bond, up to $120	Not included	Not included	Not included
Retail Value	$2,500	$995	$695	$395
Choose a program	Get All-Inclusive	Get Live Online	Get Crash Course	Get Home Study

Not sure which fits? Call 800-809-6463. Prices and inclusions are subject to change.

Labor Day

Labor Day Promo 2026

$1,449.00 $795.00

Offer ends in

Days

Hours

Min

Sec

This offer has ended.

Valid through 12:00 am PDT, October 1, 2026.

Get this bundle View offer details

What our Plumbing students say

Free Resources

Try a free C-36 Plumbing practice exam

Test your knowledge with a free 40-question practice exam and get 14 days of online access.
No credit card required.

Common Questions

C-36 Plumbing license FAQ

From application to license-in-hand, plan on 2–4 months. That covers CSLB application processing (typically 2–4 weeks), scheduling and passing both exams, and posting your $25,000 bond. With CSLS exam prep, most students are exam-ready in 4–6 weeks.

4 full-time-equivalent years of journey-level plumbing experience within the past 10 years; CSLB prorates part-time work. Qualifying work may be as a journeyperson, foreperson, supervising employee, contractor, or owner-builder. Up to 3 years can be satisfied with approved apprenticeship, technical training, or education. You'll document this on your application, so keep pay stubs and project records.

A C-36 (Plumbing) contractor installs gas piping and connections, including the gas line that feeds a furnace, but California explicitly excludes forced warm-air heating units from the C-36 scope. Installing the furnace, ducts, registers, and thermostats requires a C-20 (HVAC) license. In short: C-36 handles the gas and water piping; C-20 handles the warm-air heating equipment.

Not necessarily. A contractor who only installs water-conditioning equipment and connects it to the existing water supply with a bypass needs only a C-55 (Water Conditioning) license. The C-36 covers full plumbing systems, supply, drainage, venting, and gas. If you do general plumbing in addition to conditioning equipment, the C-36 is the right license.

Budget about $885 minimum before exam prep: the $450 application fee (covers both exams), $200 initial license issuance, roughly $150 for your first year of $25,000 bond premium, and about $85 for fingerprinting. The bond is a premium you pay, not cash you post.

The C-36 trade exam is computer-based and covers water supply, drainage and venting, gas piping, fixtures, and plumbing code. You need the current version-specific CSLB passing score to pass. With CSLS exam prep, 99% of students pass on their first attempt, backed by our 100% Money-Back Guarantee.

The mean wage for plumbers in California is $75,300 (BLS), and it runs much higher in expensive metros, the San Jose area averages around $147,087. Licensed C-36 contractors running their own businesses typically earn $70,000 to $150,000 or more, depending on their niche and the size of jobs they bid.

CSLB evaluates reciprocity case-by-case (BPC §7065.4) and may waive the trade exam if your out-of-state license has been in good standing for the past five years; CSLB names no fixed list of reciprocal states. If you hold an equivalent active plumbing license in one of those states, your C-36 trade exam may be waived, but you still must pass the California Law and Business exam and meet all other licensing requirements.

In California, any plumbing job over $1,000 requires a licensed contractor. Working unlicensed above that amount is a misdemeanor, and under Business and Professions Code §7031 an unlicensed contractor cannot sue to collect payment, even for work performed well. Getting licensed protects both your customers and your right to be paid.

Since 1985

40+ Years

200,000+

Students Licensed

99% Pass Rate

First-Time

100% Money-Back Guarantee

Tuition Refund

Become a Licensed C-36 Plumbing Contractor

What does a C-36 Plumbing contractor do?

Scope of work

High-demand specialties

Important notes

What's on the C-36 Plumbing exam?

Law & Business

C-36 Trade Exam

How to Get Your C-36 Plumbing License

Qualify

Apply to CSLB

Study & Prepare

Pass the Exam

Get Licensed

Qualify

Apply to CSLB

Study & Prepare

Pass the Exam

Get Licensed

Why get your C-36 Plumbing license?

Steady, recession-resistant demand

Specialize and earn more

Premium earning potential

C-36 vs. C-20: know the boundary

Compare C-36 Plumbing Exam Prep Programs

Labor Day Promo 2026

What our Plumbing students say

Try a free C-36 Plumbing practice exam

C-36 Plumbing license FAQ

Ready to get your C-36 Plumbing license?

Select Your Trade Classification

Exam Prep Programs, Side by Side