C-36 Exam Prep Courses Compared (2026): Every Price, What You Get, and the Guarantees

C-36 exam prep in California costs anywhere from free to $1,195, depending on whether you want practice questions, a full course, or a live class. Here is every option we could find, with the price each one shows on its own website on 2026-10-15 and a link so you can check it yourself. Full disclosure up front: we make CA Plumbing Prep, one of the options in the table. We put the others in because you are going to compare anyway, and it is better to do it with real numbers than with ads.

One thing to know before you spend anything: CSLB says there are no schools or application preparation organizations that are affiliated with or agents of CSLB. Nobody on this list, including us, has an inside line to the board. You are buying study material and practice, so compare what you actually get.

Key facts

Paid courses and practice exams

You need to pass two exams, so check whether a price covers both or only the C-36 trade exam.

How long you keep access

• CA Plumbing Prep: lifetime. No renewal and no expiry.
• RocketCert: 1 Year Access; extensions are available for $69.
• US Trade Test: one year unlimited access.
• CSLS Home Study: online practice exam access is active for 30 days from activation.
• Contractors Intelligence School Traditional Home Study: comes with a 120-day complimentary access to its online tests.
• License Instruction Schools: its online practice exam add-on includes 6 months of access, for $150.00 more.

If your application could take a while to clear, or you might need a retake, how long you keep access matters as much as the price.

Guarantees, in each provider's own words

• CA Plumbing Prep: a 14-day refund window, then a Pass Guarantee: complete every exam-prep lesson, score 85% or better on 3 full-length practice exams, and sit the real C-36 within 6 months of buying. If you do not pass, send the CSLB result letter within 30 days and every dollar is refunded.
• Contractors Intelligence School: "100% Pass Exam Money-Back Guarantee," and it says it will cover your re-test fee if you do not pass.
• At Home Prep: "No Pass, No Pay Guarantee."
• CSLS: the Home Study Program doesn't include the money-back pass guarantee; that's included with its All-Inclusive Program.
• License Instruction Schools: "We guarantee you will pass the test after attending the school," on its trade-only package.
• Peerless Institute: "No study schedule can guarantee a passing result."

Read the conditions on any guarantee before you count on it, ours included. Ours are in full on the pricing page.

Free options

Start with CSLB's own study guides whatever you buy. They list the topics on each exam and how much each section is worth. The weights are summarized in C-36 exam facts: what CSLB actually says.

How to choose

• You learn best in a classroom: a live class (License Instruction Schools, Contractors Intelligence School) is the format built for that, and it is priced for it.
• You want the lowest price that covers both exams: compare the "both exams" price, not the trade-exam price. Several C-36 prices on this page do not include Law and Business.
• You study in Spanish: CSLB offers the C-36 and Law and Business exams in Spanish. Check that your course is in Spanish too; ours is.
• You already know the trade and just need reps: start free, then buy the practice that covers the sections you are weak in.

Common questions

What is the best C-36 exam prep course?

The one that covers both exams, matches how you study, and keeps your access until you pass. Compare prices for both exams together: some C-36 prices on this page cover only the trade exam. CSLB does not endorse any school.

How much does C-36 exam prep cost?

From free to $1,195 on the pages we checked on 2026-10-15. Courses that cover both exams start at $148.75 (CA Plumbing Prep); CSLS's home study for both exams is $295; Contractors Intelligence School's full online course is $495.00.

Is there free C-36 practice?

Yes. CSLB's study guides include sample questions. PrepPass offers 360 free practice questions with no signup, and our free 21-question diagnostic needs no account.

Does CSLB recommend a school?

No. CSLB says there are no schools or application preparation organizations that are affiliated with or agents of CSLB.

Sources

• CSLB Examinations Frequently Asked Questions
• CSLB License Examination Study Guide: Plumbing (C-36)
• CSLB, Get Licensed to Build
• Peerless Institute: C-36 plumbing contractor exam prep
• RocketCert: California C-36 plumbing
• US Trade Test: C-36 plumbing contractor
• At Home Prep: California plumbing exam review
• CSLS: contractor license home study
• Contractors Intelligence School: C-36 plumbing
• License Instruction Schools: C-36 plumbing
• PrepPass: CSLB C-36
• EstatePass: California C-36

_Last reviewed: 2026-10-15. Every price above is quoted from a saved copy of the provider's own page on that date, and checked by code against that copy. Prices change; the provider's page is the final word._

See where you stand, free

Take the free 21-question C-36 diagnostic before you buy anything, from anyone. It shows you, topic by topic, where you would lose points today. If that tells you to buy our course, it is $148.75 one time for both exams, with lifetime access. See what is included.