For the owner, responsible managing officer or responsible managing employee who qualifies a California contractor license through the Contractors State License Board, covering the shared Law and Business exam and the three trade classifications a water, sewer or pipeline contractor most often holds: Class A general engineering, C-34 pipeline and C-42 sanitation system. These are separate exams, not a ladder: an original license requires both the Law and Business exam and the trade exam for the classification applied for, unless CSLB waives the exams for someone who already qualifies a license in that classification or passed both within the past five years, and in some family-business cases; a qualifier for a classification added to an existing license must also have passed both, so one who already passed Law and Business normally needs only the new trade exam. Pick the one trade exam that matches your license and study Law and Business beside it.
Start studying CSLB Contractor LicenseThe Contractors State License Board (CSLB) publishes a reference list and content outline for each exam in its study guides, not a formula sheet.
| Exam | Eligibility summary |
|---|---|
| Law and Business | A qualifying individual (the owner, a responsible managing officer, member, manager or a responsible managing employee) with at least four years of experience at the journey level, or as a foreman, supervising employee or contractor, in the classification applied for, within the ten years immediately before the application (Business and Professions Code 7068 and 16 CCR 825). Up to three of the four years may be credited for technical training, apprenticeship training or education, documented as Contractors State License Board (CSLB)'s regulations require; at least one year must be practical experience. The experience must be certified by someone in a position to know it firsthand, such as an employer, a licensed contractor the applicant worked under, or a union representative. The applicant must be at least 18 years old, pass a criminal background check by fingerprint, and, before the license issues, file the contractor's bond and proof of workers' compensation insurance or a valid exemption. |
| Class A — General Engineering | A qualifying individual (the owner, a responsible managing officer, member, manager or a responsible managing employee) with at least four years of experience at the journey level, or as a foreman, supervising employee or contractor, in the classification applied for, within the ten years immediately before the application (Business and Professions Code 7068 and 16 CCR 825). Up to three of the four years may be credited for technical training, apprenticeship training or education, documented as CSLB's regulations require; at least one year must be practical experience. The experience must be certified by someone in a position to know it firsthand, such as an employer, a licensed contractor the applicant worked under, or a union representative. The applicant must be at least 18 years old, pass a criminal background check by fingerprint, and, before the license issues, file the contractor's bond and proof of workers' compensation insurance or a valid exemption. |
| C-34 — Pipeline | A qualifying individual (the owner, a responsible managing officer, member, manager or a responsible managing employee) with at least four years of experience at the journey level, or as a foreman, supervising employee or contractor, in the classification applied for, within the ten years immediately before the application (Business and Professions Code 7068 and 16 CCR 825). Up to three of the four years may be credited for technical training, apprenticeship training or education, documented as CSLB's regulations require; at least one year must be practical experience. The experience must be certified by someone in a position to know it firsthand, such as an employer, a licensed contractor the applicant worked under, or a union representative. The applicant must be at least 18 years old, pass a criminal background check by fingerprint, and, before the license issues, file the contractor's bond and proof of workers' compensation insurance or a valid exemption. |
| C-42 — Sanitation System | A qualifying individual (the owner, a responsible managing officer, member, manager or a responsible managing employee) with at least four years of experience at the journey level, or as a foreman, supervising employee or contractor, in the classification applied for, within the ten years immediately before the application (Business and Professions Code 7068 and 16 CCR 825). Up to three of the four years may be credited for technical training, apprenticeship training or education, documented as CSLB's regulations require; at least one year must be practical experience. The experience must be certified by someone in a position to know it firsthand, such as an employer, a licensed contractor the applicant worked under, or a union representative. The applicant must be at least 18 years old, pass a criminal background check by fingerprint, and, before the license issues, file the contractor's bond and proof of workers' compensation insurance or a valid exemption. |
Four separate exams, not a ladder, and each has its own CSLB study guide with section weights CSLB itself describes as approximate: Law and Business (effective 1 December 2021) 13 / 15 / 20 / 12 / 21 / 5 / 14 percent across its seven sections; A General Engineering (1 February 2025) 15 / 6 / 15 / 21 / 11 / 9 / 5 / 18 across eight; C-34 Pipeline (1 November 2023) 21 / 35 / 12 / 12 / 20 across five; C-42 Sanitation System (1 June 2023) 27 / 26 / 10 / 10 / 27 across five. The topics in this app are those sections, prefixed with the exam they belong to, and each exam's items are allocated to its own weights; selecting an exam above scopes the quiz, the mock and the deck to its sections only. Every CSLB exam is 3.5 hours, closed book, four-choice multiple choice on a computer at a PSI test center, with a calculator provided. CSLB does not publish how many questions an exam holds, so the mock length here (35 for Law and Business, 55 for a trade exam) is this app's own practice length and is labeled as such; do not read it as the exam's. CSLB publishes no passing score, and a passing score report does not show the score (a failing one shows the overall score and a breakdown by section), so none is shown. The section headings and weights were read from the four study guide PDFs on 2026-10-08; each guide was reissued in March 2026 (forms 13E-LAW, 13E-A, 13E-34, 13E-42) without changing its effective date. Each exam carries its own topic weights, taken one-to-one from its study guide, so the Topic Mastery card scores the selected exam against its own sections. Safety appears in all four outlines but asks different things on each, which is why it is a separate topic per exam.
Topic coverage follows CSLB examination study guides: Law and Business (effective 1 December 2021), A General Engineering (1 February 2025), C-34 Pipeline (1 November 2023) and C-42 Sanitation System (1 June 2023) (Contractors State License Board). Practice questions are written to that outline and checked against the regulations and references it cites; they are not real exam questions, which are confidential. Check current application requirements, fees and exam dates on the certifying body's own page: official certification page.
Questions, flashcards, and explanations are AI-written under a sourcing policy that builds on the exam content outlines and candidate materials each certifying body publishes without restriction and the regulations and technical references they cite, and that excludes actual exam questions, recollections of any exam sat by the author, other study products, and any handbook or document released under a confidentiality agreement. Any item found outside that policy is rewritten from primary sources or removed. Content is then put through repeated review — regulatory values checked against primary sources, every calculation recomputed, and errors corrected — plus spot checks by the author, who holds California water operator certifications and a California civil engineering license. Those spot checks are sampling, not a professional review: nothing here is stamped, sealed, or offered as engineering advice, and not every item has been individually verified, so mistakes can still slip through.
Not affiliated with or endorsed by the State Water Resources Control Board (SWRCB), its Division of Drinking Water (DDW) or Wastewater Operator Certification Program (WWOCP), the California-Nevada American Water Works Association (CA-NV AWWA), the California Water Environment Association (CWEA), the National Council of Examiners for Engineering and Surveying (NCEES), the California Board for Professional Engineers, Land Surveyors, and Geologists (BPELSG), the Contractors State License Board (CSLB), or the American Public Works Association (APWA). All questions, flashcards, and references are independent study aids; verify against the official exam materials.