Construction / Plumber License / Delaware
- Delaware
- Plumber License
- Master Plumber
- Updated Oct 2026
How to Get Your Delaware Master Plumber License
This page covers Delaware’s Master Plumber license: the two paths to qualify, the open-book exam, how to apply through DELPROS and which states Delaware has reciprocity with.
Last updated October 27, 2026 from Delaware Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners requirements
Application fee
$173
Plus $100 exam fee
Exam time
3 hrs
Master Plumber exam
Time to get license
2–7 yrs
2 yrs after apprenticeship, or 7 yrs without it
Continuing ed
Not required
No CE for Master Plumbers
Overview
Do you need a Delaware plumber license?
Yes. Delaware licenses plumbers through the Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners, which covers Journey, Master and Contractor Plumbers. A Master Plumber license covers water supply, drainage and gas piping work.
License required when
- You design, install, replace, service, repair or alter pipes, fixtures and apparatus that bring water into a building
- You work on systems that remove liquid and water-carried waste from a building
- You install and connect gas piping
Common exceptions
- Apprentices and workers gaining experience under a master licensee’s supervision
- Any other exemptions aren’t listed in our sources, so check with the Board before you take on work without a license
Penalties for unlicensed work
Our sources don’t list specific penalty amounts. The Board and the Division of Professional Regulation can take enforcement action against unlicensed plumbing work, so check with the Division for current penalties.
Your fast-track Delaware plumber license checklist
The Delaware application, one page
- Apprenticeship Certificate of Completion, or proof of 7 years’ experience
- Proof of experience under a master licensee
- DELPROS account and application for exam pre-approval
- Apprenticeship By-Pass Exam, if you don’t have a certificate
- Passing score on the Master Plumber exam
Types
Delaware plumber license types and classifications
The Board licenses Journey, Master and Contractor Plumbers. This guide focuses on the Master Plumber license, which you can reach with or without a journeyman apprenticeship certificate.
MP
This guide
Master Plumber
Designs, installs, repairs and alters water supply and drainage piping and fixtures, and installs and connects gas piping.
Exam
Master Plumber exam
Limit
No limit stated
Requirements
Delaware plumber license requirements, class by class
There are two ways to qualify. If you finished an apprenticeship, you need 2 more years under a master. If you didn’t, you need 7 years and an extra exam.
| Requirement | With Journeyman Certificate | Without Journeyman Certificate |
|---|---|---|
| Apprenticeship | Certificate of Completion | Not required |
| Experience | 2+ yrs under a master licensee after your certificate | 7+ yrs under a master licensee |
| Apprenticeship By-Pass Exam | Not required | Required |
| Master Plumber exam | Required | Required |
| Exam pre-approval | Through DELPROS | Through DELPROS |
| Continuing ed | Not required | Not required |
Steps
How to get your Delaware plumber license, step by step
- Build your experience2–7 yrs
With an apprenticeship Certificate of Completion, log at least 2 years under a master licensee. Without one, log at least 7 years under a master licensee. - Start your application in DELPROSBefore you schedule
Create an account on the DELPROS portal and begin your application for exam pre-approval. Start at dpr.delaware.gov. - Take the By-Pass Exam if neededNo-certificate path
Once approved, call a Delaware apprenticeship school to schedule the Apprenticeship By-Pass Exam: New Castle County VoTech (302) 683-3643, PolyTech H.S. in Kent County (302) 697-4545 or Sussex Tech in Georgetown (302) 856-9035. - Pass the Master Plumber examExam day
100 questions, 3 hours, open book, 70% to pass. Bring bound references you can tab and highlight. - Apply for your licenseAfter you pass
Complete your application through the Division of Professional Regulation. Questions go to the Board at 302-744-4500.
Exam
What to expect on the Delaware plumber exam
The Master Plumber exam is open book. Your references must be bound, and you can tab and highlight them. Applicants without a journeyman certificate also take the Apprenticeship By-Pass Exam.
Format
Open book
Questions
100
Passing score
70%
Exam vendor
Prov
Scoring & content
- 100 questions, 3 hours, 70% to pass
- Topics include isometrics and plan reading, plumbing math, DWV, water supply, fixtures, water heaters and fuel gas
- Storm and roof drainage and safety are covered too
- References include the 2018 International Plumbing Code and 2018 International Fuel Gas Code
- All references must be bound; tabs and highlighting are allowed
Retake policy
- Retake rules aren’t listed in our sources
- By-Pass Exam dates are set through Delaware apprenticeship schools
- Each exam attempt costs $100, paid to Prov; confirm retake waiting periods with the Board
Exam references · Open book
The Delaware Master Plumber exam is open book. You can tab and highlight the references below and use them during the test, but every reference has to be bound.
| Book | Edition | Use |
|---|---|---|
| International Plumbing Code (IPC) | 2018 | Allowed in exam |
| International Fuel Gas Code (IFGC) | 2018 | Allowed in exam |
| Plumbing Basics for Contractors | Not stated | Allowed in exam |
Prep
Best Delaware plumber exam prep, compared
We haven’t compared prep courses for this exam yet.
Costs
How much does a Delaware plumber license cost?
| Item | Type | Estimate |
|---|---|---|
| Application fee | Fixed | $173 |
| Master Plumber exam | Fixed | $100 |
| Apprenticeship By-Pass Exam (if needed) | Fixed | Not stated |
| Code books and references | Variable | Varies |
| State fees and exams | $173 application plus $100 exam; excludes the By-Pass Exam, code books and renewal | $273 |
Fees from the Delaware Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners fee schedule and the Prov candidate information bulletin, checked October 2026.
Reciprocity
Does Delaware accept out-of-state plumber licenses?
Delaware has reciprocity agreements for Master Plumbers with 3 states and limited agreements with 14 more. Check with the Board for what each limited agreement covers.
Connecticut — reciprocity agreement
Delaware has a reciprocity agreement with Connecticut for Master Plumbers.
Iowa — reciprocity agreement
Delaware has a reciprocity agreement with Iowa for Master Plumbers.
Maryland — reciprocity agreement
Delaware has a reciprocity agreement with Maryland for Master Plumbers.
14 states — limited agreements
Alabama, Arkansas, District of Columbia, Florida, Georgia, Michigan, New Hampshire, New Jersey, North Carolina, Ohio, Rhode Island, South Carolina, Virginia and West Virginia. Ask the Board what’s waived for your state.
All other states — no agreement
Apply as a new applicant and meet Delaware’s experience and exam requirements.
Local
Do Delaware cities and counties have their own plumber licensing rules?
Your plumbing license comes from the state. Counties and towns still handle the job-site side of the work.
State handles
- Journey, Master and Contractor Plumber licenses
- Exam pre-approval through DELPROS
- Reciprocity agreements
- License discipline
City & county handle
- Plumbing permits
- Inspections
- Local business licenses
Governance
Who regulates plumbers in Delaware
Licensing authority
Delaware Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners
302-744-4500
Oversight responsibilities
- Issues Journey, Master and Contractor Plumber licenses
- Reviews applications and grants exam pre-approval through DELPROS
- Approves applicants for the Apprenticeship By-Pass Exam
- Manages reciprocity agreements with other states
Maintenance
How to renew your Delaware plumber license and keep it active
Delaware doesn’t require continuing education for Master Plumbers. You’re told the renewal fee when you renew, and renewing late adds a late fee of 50% of the renewal fee. Confirm the renewal cycle with the Division.
Renewal cycle
Not stated
CE hours
Not required
Renewal fee
Set at renewal
Late penalty
50% of renewal fee
Renewing your license?
See the Delaware CE guide: hours, deadline, required topics and how to renew.
FAQ
Delaware plumber license FAQs
How do I become a master plumber in Delaware?
Finish an apprenticeship and work at least 2 more years under a master licensee, or work at least 7 years under a master licensee and pass the Apprenticeship By-Pass Exam. Then pass the Master Plumber exam.
Is the Delaware master plumber exam open book?
Yes. It has 100 questions in 3 hours, and you need 70% to pass. References must be bound, and you can tab and highlight them.
What is the Apprenticeship By-Pass Exam?
It’s an extra exam for applicants without a journeyman apprenticeship certificate. Once the Board approves you, you schedule it through a Delaware apprenticeship school.
Does Delaware require continuing education for plumbers?
No. Delaware doesn’t require continuing education for Master Plumbers.
Which states have plumbing reciprocity with Delaware?
Connecticut, Iowa and Maryland have reciprocity agreements. Fourteen more states, including Florida, New Jersey and Virginia, have limited agreements.
Can a Delaware master plumber work on gas piping?
Yes. A Master Plumber can install and connect gas piping as well as water supply and drainage systems.
Sources
Official sources for the Delaware plumber license
- Delaware Division of Professional Regulation, Plumbers new license application
- Delaware Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners, Master Plumber requirements
- Delaware Master Plumber exam information
- Delaware Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners fee schedule
- Prov Candidate Information Bulletin, Delaware Division of Professional Regulation
Last updated October 27, 2026. Spot something out of date? Tell us.
Exam Insiders is an independent guide and is not affiliated with the Delaware Board of Plumbing, Heating, Ventilation, Air Conditioning and Refrigeration Examiners.