Oklahoma licenses its Mechanical Contractor — HVAC/R through the Oklahoma Construction Industries Board under the Mechanical Licensing Act. The contractor examination is one examination in two parts — a trade part and a Mechanical Business and Law part — and the trade part comes in two forms that are never interchangeable: Unlimited, at 90 questions in 240 minutes, and Limited, at 80 questions in 210 minutes for work limited to 25 tons cooling and 500,000 Btu/h heating. The PassProfessor Oklahoma Mechanical Contractor — HVAC/R program prepares candidates for both trade forms and the Oklahoma layers around them.
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What this credential certifies
The Oklahoma Mechanical Contractor — HVAC/R is a contractor license under the Mechanical Licensing Act, 59 O.S. Chapter 43A, administered by the Oklahoma Construction Industries Board under its rules at OAC Title 158, Chapter 50. A contractor, beyond performing mechanical work, plans, contracts, supervises, or furnishes labor and materials — and a contractor shall only be associated with and responsible for one mechanical firm, branch offices permitted. A journeyman performs mechanical work within a licensed category without direct supervision but contracts work only through a contractor; the journeyman examinations are separate programs and are not this program.
The HVAC/R category is examined in two forms of the one license. The Unlimited form covers installing, maintaining, repairing, servicing, and altering complete heating, ventilating, air conditioning, or refrigeration systems unlimited in horsepower or tons; the Construction Industries Board application requires Unlimited experience to be certified above 25 tons and 500,000 Btu/h. The Limited form covers the same systems limited to 25 tons cooling and 500,000 Btu/h heating — in rule terms, cooling including process piping at or below 25 tons, and heating including process piping at or below 500,000 Btu per hour per appliance, with natural gas piping, refrigeration, and sheet metal in both forms. The two forms share the same six outline domains and the same code base, but they are different sittings with different counts, different times, and different scope, and this page never merges them. Stand-alone categories — Refrigeration, Sheet Metal, Natural Gas, and Process Piping — are each taken by a separate examination and belong to separate programs.
The examination at a glance
| Item | Verified position |
|---|---|
| Program | Oklahoma Mechanical Contractor — HVAC/R: both trade forms (Unlimited and Limited), plus the Mechanical Business and Law part stated as the contractor’s second part |
| Regulator | Oklahoma Construction Industries Board (CIB), under the Mechanical Licensing Act, 59 O.S. Chapter 43A, and OAC Title 158, Chapter 50 |
| Examination vendor | PSI, under the Candidate Information Bulletin effective September 11, 2026; the CIB determines eligibility and approves the applicant |
| Unlimited trade form | 90 questions, 240 minutes, open book; pass 70 percent, printed by PSI as 63 of 90 |
| Limited trade form | 80 questions, 210 minutes, open book; pass 70 percent, printed by PSI as 56 of 80; scope limited to 25 tons cooling and 500,000 Btu/h heating |
| Business and Law part | 50 questions, 120 minutes, open book; pass 70 percent, printed as 35 of 50 |
| Tested codes | International Mechanical Code and International Fuel Gas Code, 2018 or 2024 with Oklahoma Revisions, on the transition dates stated on this page; adopted Oklahoma codes are the 2024 editions effective September 14, 2026 |
| Administrator note | PassProfessor is independent and is not affiliated with the Oklahoma Construction Industries Board |
No numeric pretest count is published for any portion this program serves, and none is stated here.
One examination, two parts — both required
A mechanical contractor license is one examination with two parts, trade and Mechanical Business and Law, and both parts must be passed. Both parts must be passed within 3 years of approval. A contractor applicant who passes only one portion need retake only the failed portion if done within three years of approval or eligibility; otherwise both portions must be retaken. After passing both parts, an inactive license is issued until the bond and insurance proofs below are received — passing is not yet active status. A passing trade portion may instead be applied to a journeyman license in the same category if the journeyman application and fees are received no more than one year after passing, and a current contractor pursuing additional categories need not retake Business and Law if previously passed.
The Business and Law part is 50 questions in 120 minutes, open book, passing at 70 percent — 35 of 50. Its sourced outline counts are stated in the companion guide; three of its topics are published only as a combined residual, and this package prints them only that way. Candidates should also keep one boundary firmly in mind: the plumbing Business and Law examination in the same PSI bulletin carries a different passing standard. That standard belongs to plumbing. It appears nowhere in this package’s mechanical copy, and it must never be carried into mechanical preparation.
Both served portions — trade and Business and Law — are written, multiple-choice examinations with no practical or drawing component, as the Oklahoma specification for these examinations states expressly. Nothing in either sitting is a hands-on component a written program cannot reach.
What the trade forms cover
The two forms share six domains, weighted differently. On the Unlimited form, as read from the bulletin: Natural Gas carries 12 questions, Air Distribution Systems 25, and Refrigeration and Air Conditioning Systems 20, with Electrical Knowledge and Controls, Heating Systems, and Safety together carrying the combined residual of 33. On the Limited form: Natural Gas carries 12, Air Distribution Systems 15, and Refrigeration and Air Conditioning Systems 20, with Electrical, Heating, and Safety together carrying the combined residual of 33. The individual split of that residual is not a published figure for either form, and this package prints the residual only as a combined figure. The Limited form is not a shortened Unlimited form — it is a differently weighted sitting for a differently scoped license. All mechanical examinations in the bulletin are open book; candidates bring their own references, with highlighting, underlining, and indexing beforehand permitted, writing in references not permitted, and tabs permanent only.
References and the 2024 transition, stated exactly
The tested reference list for the HVAC/R examinations includes the ACCA Ductulator; the International Mechanical Code, 2018 or 2024, with Oklahoma Revisions; the International Fuel Gas Code, 2018 or 2024, with Oklahoma Revisions; Modern Refrigeration and Air Conditioning, 20th, 21st, or 22nd editions — the 22nd usable as of August 13, 2026, and the 20th no longer allowed starting November 1, 2026 — or Refrigeration and Air Conditioning Technology, 5th edition (2005), which is likewise no longer allowed starting November 1, 2026; Manual N, 5th edition (2008), on the contractor lists; Mathematics for Plumbers and Pipefitters, 8th edition; and OSHA 29 CFR Part 1926. NCCER HVAC Books 1–4 are additionally allowed but were not used in examination development.
The code transition carries exact dates, and this page states them exactly. The bulletin’s transition note reads, for each code-alternating list: starting September 14, 2026 the 2024 code can be used; as of December 14, 2026 the 2018 code will no longer be used or allowed. So the tested layer runs in three phases: before September 14, 2026 the examination keyed to the 2018 editions with Oklahoma Revisions; from September 14, 2026 the 2024 editions may be used alongside the 2018 editions; after December 14, 2026 the 2018 editions are barred and the durable tested key is the 2024 editions with Oklahoma Revisions only. Preparation material in this program keys to the 2024 editions; no material here depends on a provision that exists only in the 2018 editions or that differs between 2018 and 2024.
The adopted layer is its own layer, stated separately: Oklahoma’s adopted field codes are the International Mechanical Code and International Fuel Gas Code 2024 editions with Oklahoma amendments, effective September 14, 2026 — a jump that skips the 2021 editions entirely. Tested and adopted coincide in edition from that date, but they remain different instruments: one governs the sitting, the other governs the work.
Who may sit: experience and the contractor delta
All applicants must be 18 or older. Verifiable experience means mechanical experience employed by a licensed mechanical contractor, or a Committee-approved means including United States military service. One year equals 2,000 hours. Experience gained in Oklahoma requires the apprentice to hold a Construction Industries Board apprentice registration for that period; experience obtained while unregistered does not count, except experience lawfully obtained under applicable federal or state law. The experience affidavit must be signed and notarized by a certifier with personal knowledge.
The journeyman framework underneath the contractor license sets the pattern: three years of verifiable experience in the category on the standard route, with Committee-approved education substitutions at published steps, plus routes for equivalent verifiable military experience, a category-required special certification, and a current good-standing out-of-state license. The contractor requirement is the journeyman requirements plus one additional year — four years in total on the standard route. The companion guide sets out each substitution step. Application and its fees must be received no less than three working days before the examination date, and the application fee is forfeited if the applicant fails to meet minimum qualifications. Eligibility approval carries no expiration date in the PSI layer — distinct from the three-year both-parts window above.
Fees and activation, in their separate layers
The vendor layer is PSI’s: $92 per examination portion, nonrefundable and nontransferable. The rule layer states the mechanism behind it — the Board or its designated representative may collect the actual cost of the examination — and the PSI-charged amount is the $92 in this paragraph. It is a separate instrument from every Board fee.
The Board layer is the current schedule at OAC 158:50-9-2, as charged on Construction Industries Board application forms: contractor application $30; initial contractor license $300 — a contractor total at application of $330; contractor renewal $200; contractor renewal late fee $100. A one-time low-income fee waiver exists in the Board’s rules.
Activation is not a fee. After passing both parts, the contractor holds an inactive license until the Board receives a $5,000 corporate surety bond payable to the Board, in the individual license holder’s name, continuous, with 30-day cancellation notice to the Board, and a certificate of insurance evidencing at least $50,000 of commercial general liability coverage naming the license holder, with the Board as certificate holder.
Retakes, renewal, and continuing education
After a first failure, a candidate waits 30 days; every failure after and including the second requires 90 days. Examination misconduct — cheating, impersonation, improper conduct — brings expulsion, an invalid exam, and disqualification from retaking for not less than 30 and not more than 365 days as determined by the Board’s Administrator. General sitting rules: arrive 30 minutes early, present one valid signature-bearing photo identification, and a silent, non-printing, non-programmable calculator is permitted.
A license runs not more than one year and expires the last day of the licensee’s birth month each year; the renewal application and fee must be delivered or mailed on or before that date. An expired license may be reinstated with the renewal fee, the late fee, and proof of all renewal requirements, and no license may be issued or renewed until all outstanding fines owed to any Board division are paid. One renewal election carries a permanent consequence candidates should understand before they make it: a contractor who elects to renew as a journeyman makes a permanent category change, and returning to contractor requires retaking and passing the contractor examination and meeting all contractor requirements again.
Continuing education is six hours every three years, within the 36 months preceding license expiration, for renewal of any mechanical contractor or journeyman license, with both the course and the instructor approved in advance by the Mechanical License Committee. Licensees are exempt for three years from the date they passed their current licensing examination. One credit hour is at least 50 minutes of instruction plus a 10-minute break.
Reciprocity runs by written agreement and substantial equivalence, stated in full in the companion guide at /oklahoma-mechanical-contractor-hvacr-exam-guide/. Partner-state names are not in the rule, and none are printed here.
What the PassProfessor program will cover
Both trade forms, never blended. The program prepares the Unlimited and Limited sittings as the distinct examinations they are — separate counts, separate times, separate scope — across their shared six domains at each form’s published weights, with combined residuals taught as combined figures.
The 2024 key. Material keys to the International Mechanical Code and International Fuel Gas Code 2024 editions with Oklahoma Revisions, on the transition dates this page states, with the adopted layer taught as its own layer.
Independence, stated plainly. PassProfessor is an independent preparation provider, not affiliated with the Oklahoma Construction Industries Board or PSI. Completing this program confers no license and no exemption; the Board alone licenses, and candidates schedule examinations through PSI after Board approval.
Tell me when enrollment opens. The Oklahoma Mechanical Contractor — HVAC/R program is in the works and enrollment is not yet open. Leave an email address to be notified when it is ready.
Frequently asked questions
What is the difference between the Limited and Unlimited forms?
Scope, count, and time. Limited covers systems limited to 25 tons cooling and 500,000 Btu/h heating, at 80 questions in 210 minutes. Unlimited covers systems unlimited in horsepower or tons, at 90 questions in 240 minutes.
What score passes each part?
70 percent on every part, printed by PSI with its raw count: 63 of 90 on the Unlimited trade form, 56 of 80 on the Limited trade form, and 35 of 50 on the Business and Law part.
Must a contractor pass both parts?
Yes. The contractor examination is one examination in two parts, and both parts must be passed within 3 years of approval. After passing both, an inactive license issues until the bond and insurance proofs are received.
Which code editions does the examination use?
The 2024 editions with Oklahoma Revisions became usable September 14, 2026, alongside the 2018 editions; after December 14, 2026 the 2018 editions are no longer used or allowed. Oklahoma’s adopted field codes are the 2024 editions effective September 14, 2026.
How much experience does a contractor applicant need?
The journeyman requirements plus one additional year — four years of verifiable experience on the standard route, where one year equals 2,000 hours employed by a licensed mechanical contractor, with Oklahoma experience counted only for periods of Board apprentice registration.
What does the examination cost?
PSI charges $92 per examination portion. Board fees are separate: $30 contractor application and $300 initial contractor license, a total of $330 at application, with renewal at $200 and a $100 renewal late fee.
What activates the license after passing?
A $5,000 corporate surety bond payable to the Board and a certificate of insurance evidencing at least $50,000 of commercial general liability coverage, with the Board as certificate holder.
Is PassProfessor affiliated with the Construction Industries Board?
No. PassProfessor is an independent preparation provider. The Board alone licenses mechanical contractors in Oklahoma.
When does enrollment open?
The program is in the works and enrollment is not yet open. Leave an email address on this page to be notified when it is ready.