ILLINOIS · plumber
Illinois Licensed Plumber
Illinois Department of Public Health — Plumbing Program →Scope of Work
The Illinois Licensed Plumber credential, issued by the Illinois Department of Public Health (IDPH) under the Illinois Plumbing License Law (225 ILCS 320), authorizes the holder to install, alter, extend, and repair plumbing systems in Illinois. Illinois is a single-tier state: there is no separate 'journeyman' and 'master' plumber license. A licensed plumber who contracts for plumbing work in his or her own name, or who employs other plumbers, must additionally register the business as a Plumbing Contractor with IDPH. Source: IDPH Plumbing Program (https://dph.illinois.gov/topics-services/environmental-health-protection/plumbing.html).
Apprenticeship Pathway
Each applicant must have served a minimum of four years as an Illinois-licensed apprentice plumber, with the term of apprenticeship not less than 1,400 hours per year, for a total of 5,600 hours. An alternative pathway allows two years as an Illinois-licensed apprentice plumber combined with two years of approved plumbing coursework (two credit hours granted per classroom hour, not to exceed 24 months' credit) to reach the same 5,600-hour total. Applicants must also have completed at least a two-year course of study in high school or an equivalent course of study equal to 10 credit hours. Source: Ill. Admin. Code tit. 68, Part 750.300 (https://www.law.cornell.edu/regulations/illinois/Ill-Admin-Code-tit-68-SS-750.300).
Out-of-state Credit
Licensed apprentices from other states receive credit on an hour-for-hour basis toward the 5,600-hour requirement. Out-of-state licensed plumbers must submit documentation verifying their original license required testing in plumbing design, practical skills, and standards knowledge. Source: Ill. Admin. Code tit. 68, Part 750.300.
Exam
The plumber licensing examination is administered directly by IDPH. Applications must be postmarked at least 30 days before the examination date. IDPH examines not more than 50 applicants per session (not more than 40 during winter months) and schedules the exam at least once every three months; 2026 published dates include May 14, June 16, June 17, and September 8. Core topics include the Illinois Plumbing Code (77 Ill. Adm. Code 890), public health and state licensing law, materials and fixtures, drainage and venting, water distribution, traps and interceptors, and safety and inspection procedures. Source: IDPH Plumber Licensing Exam schedule (https://dph.illinois.gov/events/2024/march/plumber-licensing-exam.html).
FEES
Per the IDPH Plumber's License Application for Examination (revised 06/24/2021), the examination application fee is $175 for Illinois applicants and $225 for applicants registered or licensed in Chicago or outside Illinois. A retake examination requires a new application and $175 fee. Source: IDPH Application for Examination (https://dph.illinois.gov/content/dam/soi/en/web/idph/forms/topics-services/environmental-health-protection/plumbing/plumber-license-examination-application-06242021.pdf).
Reciprocity
Illinois does not maintain formal plumber-licensing reciprocity agreements with other states; out-of-state licensed plumbers apply through the IDPH endorsement process described above. A separate Chicago-to-state reciprocity application exists for plumbers already licensed by the City of Chicago. Source: IDPH Chicago Reciprocity Application (https://dph.illinois.gov/content/dam/soi/en/web/idph/files/forms/plumber-license-reciprocity-chicago-application-042616.pdf).
Renewal and CE
Plumber licenses expire April 30 following the date of issuance and are renewed annually through IDPH's online renewal portal. Licensed plumbers must complete 4 hours of IDPH-approved continuing education each license year; new licensees are exempt from CE during the first license year. Source: IDPH Plumbing Continuing Education Listing (https://dph.illinois.gov/topics-services/environmental-health-protection/plumbing.html).
Scope Limitations
The Licensed Plumber credential authorizes the individual to perform plumbing work but does not by itself authorize contracting. A firm advertising, bidding, or contracting for plumbing work must register as a Plumbing Contractor with IDPH (separate $150 annual registration under 225 ILCS 320). Plumbing inspection work requires a separate Certified Plumbing Inspector credential. Source: IDPH Plumbing Program.