Illinois Plumber License Requirements (2026)
By Gabriel Giner, Editor · Reviewed 2026-05-30 · CLR Editorial Review Desk
Illinois is one of the few states that licenses plumbers at the state level even though it does not license general contractors, electricians, or HVAC. The Illinois Department of Public Health (IDPH) administers the Plumbing License under the Illinois Plumbing License Law (225 ILCS 320). Illinois issues two credentials — the Licensed Plumber (an individual credential earned by passing the IDPH examination after completing a four-year apprenticeship) and the Plumbing Contractor Registration (a business credential held by any plumbing business operating in Illinois). Every plumbing business must have at least one Licensed Plumber as the responsible plumber in charge.
Governing Authority
Under Illinois Plumbing License Law (225 ILCS 320); Illinois Plumbing Code (77 Ill. Adm. Code 890), Illinois Department of Public Health — Plumbing Program (IDPH) is the body that issues this license and enforces compliance with it. IDPH licenses plumbers, plumbing apprentices, irrigation contractors, plumbing contractors, and retired plumbers under the Illinois Plumbing License Law. The Illinois Plumbing Examiners Board approves the state plumbing examination and reviews disciplinary actions.
- Official portal: https://dph.illinois.gov/topics-services/environmental-health-protection/plumbing.html
- Address: 525 W. Jefferson Street, Springfield, IL 62761
- Phone: (217) 782-5830
Eligibility Requirements
To qualify, an applicant must have reached age 18 and hold a valid Social Security Number. No Illinois residency requirement.
Good moral character
IDPH conducts a fitness review on every applicant. Convictions for theft, fraud, or plumbing-related offenses are reviewed individually.
Background investigation
IDPH conducts a background check via the Illinois State Police for all initial applicants.
Experience & Education Matrix
Eligibility requires four years (six 1,500-hour years for apprentices on the formal apprenticeship track) of practical experience as a registered Illinois Plumbing Apprentice under the direct supervision of a Licensed Illinois Plumber, documented and independently verifiable. Payroll, tax, project, and supervisor records are the usual proof the board will accept.
Accepted proof of experience or eligibility
- IDPH Plumbing Apprentice Registration on file for the full four-year period
- Apprentice work record affidavits signed by each supervising Licensed Plumber
- W-2 statements, pay stubs, or 1099 records covering the apprenticeship period
Education substitution
Graduation from an IDPH-approved plumbing trade school does not eliminate the apprenticeship requirement but may shorten it. The IDPH-approved formal apprenticeship programs (typically run by UA Local unions and private schools) integrate classroom and field hours.
Examination Structure
The licensing examination is delivered by Continental Testing Services (under contract to IDPH and the Illinois Plumbing Examiners Board). All of the following parts must be cleared prior to issuance:
- Illinois Plumber Examination — Plumbing Code (77 Ill. Adm. Code 890), plumbing law, water supply, drainage, fixtures, gas piping — 100 questions, 240 minutes, passing score 75%
Examination fee: Approximately $300 examination fee paid to Continental Testing Services. The Illinois Plumbing Examiners Board administers the examination twice per year on fixed dates.
Retake policy: Each section requires a minimum of 61% and the overall test requires 75% to pass. Failed sections may be re-taken at the next administration; passing sections remain valid for two years.
Insurance & Financial Security
This credential carries no state-level surety bond requirement under the cited sources. Individual jobs may still trigger a permit or public-works bond, which should be verified before bidding.
General liability
IDPH requires plumbing contractors registered with the Department to carry general liability insurance with minimum coverage set by IDPH rule. Most Illinois plumbing contractors carry $1,000,000/$2,000,000 to satisfy commercial owners.
Workers' compensation
Workers' compensation insurance is mandatory in Illinois under the Illinois Workers' Compensation Act for any business with employees.
Application and License Fees
| Fee | Amount |
|---|---|
| Application (non-refundable) | $175 |
| Examination | $300 |
| Initial license | $175 |
| Renewal (every year) | $145 |
Maintenance & Renewal
Expect to renew the Illinois Licensed Plumber (IDPH) every year. Renewal currently costs $145. Illinois plumbing licenses renew annually on the anniversary of issuance. Apprentice registrations also renew annually throughout the apprenticeship.
Continuing education: Four hours of IDPH-approved continuing education each renewal cycle, covering Illinois Plumbing Code updates and plumbing law.
Downloadable Asset
2026 Illinois Plumber License Roadmap (PDF) — a printable step-by-step checklist for the application process.
Download the PDF roadmap →Reciprocity and Endorsement
Illinois does not accept the NASCLA Accredited Examination for this classification.
| Reciprocal State | Accepted Exam | Conditions |
|---|---|---|
| Indiana | Trade exam waived | Bilateral IDPH–Indiana Plumbing Commission reciprocity for active licensed plumbers in good standing. |
| Iowa | Trade exam waived | Bilateral IDPH reciprocity for active licensed plumbers. |
| Wisconsin | Trade exam waived | Bilateral IDPH reciprocity for active master plumbers in good standing. |
IDPH maintains a small number of bilateral plumbing reciprocity agreements with neighboring states. Plumbing is not a NASCLA-administered trade.
Weighing more than one jurisdiction? The national hub compares Plumber license requirements in every state — exam, bond, fee, and experience thresholds side by side.
Step-by-Step Application Roadmap
- Register as an Illinois Plumbing Apprentice with IDPH. Submit the IDPH Plumbing Apprentice Registration with a sponsoring Licensed Plumber. Apprentice registration must be renewed annually.
- Complete four years of supervised apprenticeship. Work under a Licensed Illinois Plumber and complete IDPH-approved classroom hours. The formal apprenticeship integrates 1,500 hours per year of field work with classroom training.
- Submit the Plumber Examination Application to IDPH. File the application after completing the apprenticeship requirement. IDPH staff verify the apprentice registration history and authorize the examination.
- Sit for the Illinois Plumber Examination. Continental Testing Services administers the examination twice per year on fixed dates. Score 75% overall and 61% on each section to pass.
- Receive the Licensed Plumber credential. IDPH issues the Licensed Plumber wallet card after the examination. The license must be renewed annually with continuing education.
- Register the plumbing business with IDPH. A plumbing business operating in Illinois must register as a Plumbing Contractor with IDPH and designate a Licensed Plumber as the responsible plumber in charge. The Plumbing Contractor Registration is a separate credential from the individual Licensed Plumber.
Study and Reference Materials
These are the preparation and reference materials tied to this credential — cited by the regulator or widely used by applicants. CLR earns nothing from listing them.
- Illinois Plumbing Code (77 Ill. Adm. Code 890) — State of Illinois. Primary technical reference for the Illinois Plumber Examination.
- Illinois Plumbing License Law (225 ILCS 320) — Illinois General Assembly. Statutory basis for Illinois plumbing licensing — heavily tested.
- UA Plumbing Apprenticeship curriculum — United Association of Plumbers and Pipefitters. Standard curriculum used by Illinois apprentices.
Common Filing Mistakes
Drawn from the board instructions and sources cited on this page, the pitfalls below are the ones most likely to slow down or sink a Illinois Plumber application.
Skipping apprentice registration
Hours worked as an unregistered apprentice do NOT count toward the four-year requirement. IDPH requires the apprentice registration on file from day one and renewed annually.
Failing one section despite a strong overall score
The Illinois Plumber Examination requires 61% on every section AND 75% overall. Candidates who score 80% overall but 55% on one section still fail and must retake that section.
Forgetting the Plumbing Contractor Registration
The individual Licensed Plumber credential does NOT authorize a business to operate. The plumbing business must separately register with IDPH as a Plumbing Contractor and designate a Licensed Plumber as the responsible plumber in charge.
Missing the bi-annual examination window
IDPH and the Illinois Plumbing Examiners Board administer the examination on fixed dates twice per year. Candidates who miss the registration deadline lose six months of progress.
Letting the annual license lapse
Illinois plumbing licenses renew annually. A lapsed license cannot legally qualify a Plumbing Contractor Registration, exposing the business to enforcement.
Pre-Submission Checklist
The most critical documents or confirmations the applicant should have in hand before filing with IDPH:
- ☐ IDPH Plumbing Apprentice Registration on file for the full four-year apprenticeship period
- ☐ Apprentice work record affidavits signed by each supervising Licensed Illinois Plumber
- ☐ Continental Testing Services Plumber Examination passed at 75% overall and 61% per section
- ☐ IDPH Plumbing License application with $175 fee
- ☐ IDPH Plumbing Contractor Registration (for the business)
Other Illinois Trade Licenses
If the Plumber license is not the right fit, the following published Illinois trade guides are also covered by CLR:
Frequently Asked Questions
Does Illinois require a state plumbing license?
Yes. Illinois is one of the few states that licenses plumbers at the state level even though it does not license general contractors, electricians, or HVAC. The Illinois Department of Public Health administers the Plumbing License under the Illinois Plumbing License Law (225 ILCS 320).
How many years of apprenticeship does Illinois require for a plumbing license?
Four years of registered apprenticeship under a Licensed Illinois Plumber. Apprentices must register with IDPH and renew the registration annually throughout the apprenticeship.
What is the passing score on the Illinois plumber examination?
A minimum of 61% on each section AND 75% overall. Both thresholds must be met to pass. Failed sections may be re-taken at the next administration.
What is the difference between the Illinois Licensed Plumber and the Plumbing Contractor Registration?
The Licensed Plumber is the individual credential earned by passing the IDPH examination after completing the apprenticeship. The Plumbing Contractor Registration is a business credential held by any plumbing business operating in Illinois. Every business must designate a Licensed Plumber as the responsible plumber in charge.
How often does the Illinois plumbing license renew?
Annually. Renewal requires the standard fee plus continuing education hours covering Illinois Plumbing Code updates.
Primary Sources
Regulatory requirements on this page are drawn from the official board, statute, and exam-provider materials listed below.
- IDPH — Plumbing Program
- Illinois Plumbing License Law (225 ILCS 320)
- Illinois Plumbing Code (77 Ill. Adm. Code 890)
- Continental Testing Services — IDPH plumbing exam information
Verified 2026-05-30 · Next scheduled review 2026-08-28