Ohio’s statewide plumbing credential is the Plumbing Contractor license issued by the Ohio Construction Industry Licensing Board (OCILB) — an individual license for commercial work that must be assigned to a contracting company. Candidates are Board-approved, complete a federal (FBI) and state (BCI) background check before sitting, and pass a 100-question open-book trade examination at 70 percent, in which Isometric Analysis alone carries 20 of the 100 scored items. The PassProfessor Ohio OCILB Plumbing Contractor program prepares candidates for the written portions of that trade examination and for the Ohio code layer it actually tests.
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What this credential is — and what it is not
Ohio licenses plumbing at the state level in exactly one way: through the OCILB Plumbing Contractor license. It is one of five OCILB contractor license types, it covers commercial work, and it is issued in an individual’s name — yet it does not function as a personal credential the holder carries from job to job on their own account. The license must be assigned to a contracting company, only one company at a time. If it is not assigned, the license is placed in inactive status. The contracting company is where the license does its legal work, and a candidate who understands that assignment structure understands the shape of the whole Ohio system.
Just as important is what Ohio does not issue. There is no statewide license tier above or below this one for individual plumbers: credentialing for work beneath the contractor level is handled locally, by cities and counties, and is not a state product at all. The OCILB contractor license is the entire statewide plumbing ladder, and the sitting described on this page is the only statewide plumbing examination Ohio offers.
The licensing authority is the Ohio Construction Industry Licensing Board, within the Department of Commerce, Division of Industrial Compliance, acting under Ohio Revised Code Chapter 4740 and Ohio Administrative Code Chapter 4101:16. Within the board, the plumbing and hydronics section designs the plumbing contractor examination; the administrative section schedules examinations and issues and renews licenses. Examinations are delivered by PSI Services LLC (PSI).
The examination at a glance
| Item | Verified position |
|---|---|
| Program | Ohio OCILB Plumbing Contractor: the statewide commercial plumbing contractor license |
| Regulator | Ohio Construction Industry Licensing Board (OCILB), Department of Commerce, Division of Industrial Compliance |
| Credential form | Individual license that must be assigned to one contracting company; inactive if unassigned; commercial work |
| Before sitting | OCILB approval first, then a federal (FBI) and state (BCI) background check, before scheduling with PSI |
| Trade examination | 100 scored questions / 4 hours / open book / pass at 70 percent, via PSI |
| Isometric Analysis | 20 of the 100 scored trade items — a drawing-interpretation block inside the written examination (see the disclosure below) |
| Second required sitting | The Contractor’s Business and Law examination — 50 scored questions / 2 hours / 70 percent — sits separately and is required in addition to the trade examination |
| Hands-on practical | None. There is no hands-on practical examination |
| Tested references | Ohio Plumbing Code, 2024, and International Fuel Gas Code, 2024 |
| Adopted code layer | The 2024 Ohio Plumbing Code (Ohio Administrative Code 4101:3, effective March 1, 2024), which incorporates the 2021 International Plumbing Code, Chapters 2 through 15, with Ohio amendments — expressly not the 2024 International Plumbing Code |
| Examination fee | PSI charges $69 per registration |
| OCILB figures | $25 application for examination / $25 issuance of a license / $60 annual renewal per license |
| Continuing education | 10 classroom hours of an approved course each year |
| Administrator note | PassProfessor is independent and is not affiliated with the Ohio Construction Industry Licensing Board |
Two sittings, not one
Ohio contractor licensing requires two separate examinations, never to be blended into a single sitting in a candidate’s planning. The first is the Plumbing Contractor trade examination described throughout this page. The second is the Contractor’s Business and Law examination: 50 scored questions, 2 hours, open book, passing at 70 percent. Every applicant for a contractor commercial license must pass it in addition to the trade examination; a candidate who later seeks another OCILB trade license needs to pass it only once every three years. This PassProfessor program covers the trade examination; the Business and Law sitting is noted here for structure, so no candidate mistakes a trade pass for a completed licensing route.
The trade examination, block by block
The trade examination is computer-based and multiple-choice, delivered by PSI, and open book: candidates bring their own references, which may be highlighted, underlined, and indexed before the session and tabbed with permanent tabs only. An online calculator and scratch paper are provided at the center, and only the provided calculator may be used. The published content outline distributes the 100 scored items as follows: Drainage, Waste, and Sanitary Vents, 24 items — the largest trade block; General Regulations, 20; Isometric Analysis, 20; Water Supply Systems, 10; General Knowledge, 8; Plumbing Fixtures, 6; Specialty Plumbing, 5; Roof Drain Piping, 4; and Indirect Wastes, 3.
Read that distribution carefully: the drainage and venting block plus General Regulations account for 44 of the 100 scored items between them, before the drawing block is counted at all. This is a code-navigation examination as much as a knowledge examination — open book puts the references in the room, but four hours across 100 items leaves little time for searching a book the candidate does not already know how to move through.
The isometric disclosure, stated plainly
Twenty of the 100 scored items — one item in five — form the Isometric Analysis block, the second-largest block on the examination. Those items test interpretation of isometric drawings inside the computer-based examination. They are not a hands-on practical; Ohio has no hands-on practical examination. But they are drawing work, and a text-based practice program cannot replicate them.
PassProfessor states that limit directly: this program prepares candidates for the written portions of the trade examination, and it does not — and cannot — promise coverage of the full examination. A candidate who worked only the written material would be preparing for at most 80 of the 100 scored items. The honest Ohio study plan therefore has two tracks: disciplined preparation on the written blocks, and separate, deliberate practice reading isometric drawings.
The code layer: the name of the book is the trap
The examination reference list names the Ohio Plumbing Code, 2024, and the International Fuel Gas Code, 2024, alongside Mathematics for Plumbers and Pipefitters, 8th Edition, and Modern Plumbing, 9th Edition. The bulletin rule is that, for code questions, the examinations will be based only on the edition of the code book that is listed — and where references conflict, a legal requirement overrides any other reference and a state-specific code, law, or regulation overrides a national one.
The adopted layer underneath that reference list needs exact statement, because its name misleads. The 2024 Ohio Plumbing Code, at Ohio Administrative Code 4101:3, effective March 1, 2024, incorporates by reference the International Plumbing Code, 2021 edition, Chapters 2 through 15, together with Ohio amendments. It is expressly not the 2024 International Plumbing Code. A value in the 2024 national plumbing code does not apply in Ohio merely because the Ohio book carries the year 2024 in its title. Preparation composed from national 2024 material will teach answers the Ohio examination does not key, on precisely the kind of detail — a fixture value, a materials rule — where a candidate is most likely to trust a memorized number. This program is composed to the Ohio book, as the examination’s own reference list directs.
Who may sit: the eligibility routes
There is no rung-by-rung state ladder to climb into this examination, because there are no lower statewide licenses. Eligibility instead runs on experience. The standard route requires the applicant to be at least 18 years of age, to be a United States citizen or a legal alien who produces valid documentation of legal residence, to meet the clean-conduct requirements of the chapter, and to show experience as a tradesperson in the plumbing trade for not less than five years immediately before the application filing date.
Two further routes stand beside the standard one. A person currently registered as an engineer in Ohio qualifies with three years of business experience in the construction industry in the plumbing trade. The OCILB application also lists five years of experience as an Ohio government inspector in the plumbing trade as an alternative route. Documentation on the standard route is demanding: tax documents covering the last five consecutive years, plus one listed supporting proof — permits obtained by the licensed contractor the applicant worked under, a locally issued card in the trade, an apprenticeship completion certificate from a state- or federally approved program, or proof of 40 hours of non-duplicated continuing education in code from an OCILB-approved training agency, taken live or virtual rather than self-guided. Candidates should assemble that file early; approval, not inclination, opens the examination door.
Approval has a clock. OCILB approval is valid for one year, and once PSI is notified of eligibility the candidate has one year to schedule and take the examination, after which eligibility expires. After approval and before sitting, the candidate must obtain the federal (FBI) and state (BCI) background check. Results are given immediately on completion, as a printed pass or fail report, with diagnostic information on a fail report.
The dollars, by layer
The examination fee and the board’s fees are separate layers. PSI charges $69 per registration, first attempt or repeat; registration fees are not refundable or transferable. The OCILB figures, set in Rule 4101:16-2-09, are $25 for the application for examination, $25 for issuance of any license, and $60 for annual renewal per license, with a late fee of not more than $120 per license; OCILB fees are nonrefundable. After passing both examination sections, licensure also requires proof of at least $500,000 of contractor liability insurance, including completed operations coverage — a financial-responsibility requirement, not a fee, and no state bond is imposed by the statute or rules behind this license.
Retakes follow a fixed rhythm: a candidate who fails must wait 60 days before retesting, and may retest up to five times in a year; an applicant who has taken the examination five times without passing must reapply before retaking again.
Holding the license: assignment, renewal, and continuing education
All licenses a contractor holds expire annually on the same date — the original license’s expiration date. Renewal is made without reexamination, by applying not more than 90 calendar days before expiration, with the renewal fee and proof of continuing education compliance. The requirement is 10 classroom hours of an approved course each year — the aggregate across all licenses held, not per license. A classroom hour is at least 50 minutes of instruction, no more than 10 classroom hours in one calendar day earn credit, and excess hours do not carry over. Failure to meet the requirement by the expiration date suspends the license automatically, without board action; reactivation is available within one calendar year after expiration, after which the license is automatically revoked. Underneath renewal sits the assignment rule that defines the credential: the license must remain assigned to its one contracting company, with the required liability insurance maintained — an unassigned license sits inactive, whatever its renewal status.
What the PassProfessor program will cover
The Ohio OCILB Plumbing Contractor program in the PassProfessor catalog is composed to the examination Ohio actually gives. Its center of gravity follows the published outline: drainage, waste, and venting first, then General Regulations, water supply, fixtures, and the smaller blocks in their published proportions. Its code layer is the Ohio layer — the 2024 Ohio Plumbing Code as adopted at Ohio Administrative Code 4101:3, built on the 2021 national code’s Chapters 2 through 15 with Ohio amendments — and the 2024 International Fuel Gas Code as listed. Material keyed to the national 2024 plumbing code is not Ohio preparation, and this program does not present it as such. Its limits are the ones disclosed above: the Isometric Analysis block requires separate drawing practice no text program can supply. The companion guide at /ohio-master-plumber-exam-guide/ walks the full route in depth.
Independence, stated plainly. PassProfessor is an independent preparation provider, not affiliated with the Ohio Construction Industry Licensing Board, PSI, or the Department of Commerce. Completing this program confers no license and no exemption; the OCILB alone licenses, and candidates register for examinations through PSI after board approval.
Tell me when enrollment opens. The Ohio OCILB Plumbing Contractor program is in the works and enrollment is not yet open. Leave an email address and PassProfessor will write to you when the program is ready — and only about this program. No date is promised, because the program will open when it meets the standard described above, not before.
Frequently asked questions
What is Ohio’s statewide plumbing license called?
The Plumbing Contractor license issued by the Ohio Construction Industry Licensing Board (OCILB). It is an individual license for commercial work that must be assigned to a contracting company.
How many examinations must I pass?
Two separate sittings: the Plumbing Contractor trade examination, and the Contractor’s Business and Law examination. Both are required.
How is the trade examination structured?
100 scored questions in 4 hours, open book, delivered by PSI. The passing standard is 70 percent.
What is Isometric Analysis on this examination?
A block of 20 of the 100 scored items testing interpretation of isometric drawings inside the computer-based examination. It is not a hands-on practical — Ohio has none — but a text program cannot replicate the drawing items, and this program does not promise full-exam coverage.
Which code book does the examination test?
The Ohio Plumbing Code, 2024, and the International Fuel Gas Code, 2024, as listed in the PSI bulletin.
Is the Ohio book the 2024 national plumbing code?
No. The 2024 Ohio Plumbing Code (Ohio Administrative Code 4101:3, effective March 1, 2024) incorporates the 2021 International Plumbing Code, Chapters 2 through 15, with Ohio amendments. National 2024 values do not apply in Ohio by virtue of the Ohio book’s title year.
What must happen before I can schedule with PSI?
OCILB approval first, and a federal (FBI) and state (BCI) background check after approval and before sitting. Eligibility is determined by the OCILB, not PSI.
What experience does the standard route require?
Work as a tradesperson in the plumbing trade for not less than five years immediately before filing. Registered-engineer and Ohio government-inspector routes are also sourced, with their own terms.
How much continuing education does renewal require?
10 classroom hours of an approved course each year, in aggregate across all licenses held.
Is PassProfessor affiliated with the OCILB?
No. PassProfessor is an independent preparation provider. The OCILB alone licenses plumbing contractors in Ohio.
When does enrollment open?
The program is in the works and enrollment is not yet open. Leave an email address on this page and PassProfessor will write to you when the program is ready — and only about this program.