Iowa HVAC License Requirements — PMSB Credentials for Mechanical Contractors

HVAC Is a State-Licensed Specialty in Iowa

HVAC work in Iowa falls under the Plumbing and Mechanical Systems Board (PMSB), which regulates mechanical contractors, refrigeration technicians, hydronics installers, and sheet metal workers alongside plumbers. The state preempts local authority for these trades — your PMSB credential is valid statewide, and no city can add its own mechanical licensing requirements.

General contractors cannot perform HVAC work under their DIAL registration alone. If your contracting business installs, repairs, or maintains heating, ventilation, air conditioning, or refrigeration systems, you need a PMSB contractor license with a licensed Master of Record on staff.

License Classes for HVAC/Mechanical Work

The PMSB issues several mechanical license classes:

Mechanical Apprentice — Entry-level registration for workers training under a licensed journeyman or master. No exam required.

Journeyman Mechanical — The credential for performing HVAC/mechanical installations and service work. Requires passing the Kirkwood Community College trade exam.

Master Mechanical — The supervisory credential. Required to be a company's Master of Record. More extensive exam and experience requirements.

Mechanical Contractor License — The business credential. Issued jointly with DIAL contractor registration through a combined application. Requires an active Master of Record.

The license categories cover HVAC, refrigeration, hydronics, and sheet metal as a unified discipline under the PMSB. You do not need separate licenses for each sub-specialty.

Exam Process

PMSB mechanical exams are administered through Kirkwood Community College at 15 testing sites across Iowa. The process is identical to plumbing exams:

1. Submit an exam approval application to the PMSB with the $35 state exam approval fee
2. Wait for board sponsoring approval
3. Register with Kirkwood Community College ($35 exam registration fee)
4. Take the exam

The exams are open-book and reference the relevant mechanical codes. Passing score is 75%. If you fail, you must wait 30 days before scheduling a retake.

No Reciprocity for Mechanical/HVAC

This is the major difference between mechanical and electrical licensing in Iowa. While the Electrical Examining Board maintains reciprocity with 13 states, the PMSB maintains zero reciprocity agreements for mechanical, HVAC, refrigeration, or hydronics licenses.

If you hold a mechanical license in Minnesota, Illinois, Nebraska, or any other state, you still need to go through the full Iowa exam process. No exceptions, no exam waivers, no expedited pathways based on out-of-state credentials.

This catches a lot of out-of-state HVAC contractors by surprise, especially those working border-state projects. Budget the exam timeline into your project planning if you're expanding into Iowa.

(Plumbing is slightly better — the PMSB has a reciprocity agreement with South Dakota for plumbing, but not for mechanical.)

Fees Follow the Triennial Cycle

PMSB mechanical licenses renew on the same three-year cycle as plumbing. The current cycle runs July 1, 2026, through June 30, 2029.

For the combined Mechanical Contractor License + DIAL Registration, fees are prorated by entry date:

• July–December, Year 1: $400.00 total
• January–June, Year 1: $333.50
• July–December, Year 2: $266.75
• January–June, Year 2: $200.00
• July–December, Year 3: $133.25
• January–April, Year 3: $66.75

Renewal at the end of the cycle costs $466.75. Paper applications carry a $25 surcharge — file online to avoid it.

If you apply for multiple license classes on the same day (e.g., both mechanical and plumbing), a 30% discount applies to the license fee portion. This can save over $100 if you're credentialing across multiple PMSB disciplines.

Insurance and Bond Requirements

PMSB-licensed mechanical contractors must carry:

• $500,000 minimum public liability insurance
• $5,000 surety bond

These are the same minimums as plumbing contractors. If your business also has employees, you still need workers' comp insurance and potentially the $25,000 DIAL registration bond on top of the PMSB requirements.

Continuing Education

Mechanical licensees must complete 8 classroom hours of board-approved continuing education during each 3-year cycle:

• 2 hours of safety
• 2 hours of code
• 2 hours of discipline-specific content
• 2 hours of elective content

No more than 4 hours can be completed online. CE must be finished before the renewal window opens.

HVAC Licensing Within Your Contracting Business

If you're a general contractor expanding into HVAC work, the practical path is:

1. Hire or partner with a licensed Master Mechanical who can serve as your Master of Record
2. Apply for the combined PMSB Contractor License + DIAL Registration
3. Meet the $500,000 liability and $5,000 bond requirements
4. Ensure your employees performing HVAC work hold appropriate apprentice or journeyman credentials

The PMSB contractor license is a business credential — it authorizes your company to contract for mechanical work. The individual workers still need their own journeyman or apprentice registrations.

Complete Licensing Path for Multi-Trade Contractors

The Iowa General Contractor License Guide covers the full PMSB licensing process alongside DIAL registration, including the joint application procedure, insurance stacking across multiple credentials, and city-by-city permit requirements for mechanical work.

See more Iowa guides →