You get into a union HVAC apprenticeship by applying to the training program a local union runs with its signatory contractors — a United Association (UA) local for HVACR service work, or a SMART local if sheet metal is your target.
UA apprenticeships are registered with the U.S. Department of Labor and typically run five years, and you earn a wage while you train.
Application windows, aptitude testing and pay steps are set local by local.
Here is how it works.
Which unions train HVAC techs
Two unions train HVAC techs on the union side of the trade, and they cover different parts of it.
The first is the United Association (UA), the North American union of the pipe trades.
Alongside plumbers, pipefitters, sprinkler fitters, steamfitters and welders, the UA lists HVACR service technicians among its trades, and its apprenticeship tracks include HVACR alongside plumbing, sprinkler fitting, pipefitting, steamfitting and welding.
By the UA's own count, it represents approximately 409,000 workers across North America, Canada included.
HVACR service work — servicing air-conditioning and refrigeration equipment — sits inside UA locals, and some locals put it in their own name.
UA Local 421, which covers North and South Carolina and trains from centers in Raleigh and Charlotte, runs its JATC apprenticeship as Plumbers, Pipefitters, Welders and HVAC-R Service Techs.
In Indianapolis, the equivalent is Plumbers, Steamfitters & HVACR Service Technicians Local 440.
Names vary by local, and two examples do not prove what your nearest local runs — that is a question to ask it.
The second union is SMART, which trains the sheet metal side of the trade.
SMART partners with SMACNA, the sheet metal contractors' association, to jointly sponsor the International Training Institute (ITI), which runs sheet-metal apprenticeship training through affiliated training centers and reports more than 14,000 registered apprentices in the US and Canada.
Those apprenticeships run four or five years.
From the metal side of HVAC, SMART local programs cover the ductwork and equipment you would expect — SMART Local 49's JATC in New Mexico, for example, lists a sheet metal apprenticeship covering HVAC systems, architectural sheet metal, welding and fabrication.
If you want the union itself rather than its apprenticeship — how locals are organized and what membership involves — we cover that separately in the UA explained.
The rest of this page stays on the apprenticeship.
How union HVAC apprenticeships work
Union apprenticeships do not run out of a national office.
Each local runs its program through a JATC — a joint apprenticeship and training committee, the joint body a local forms with the contractors that hire its apprentices — and the JATC runs intake, classroom instruction and the training center.
What union programs share is their registration: the UA says its apprenticeships are registered with the U.S. Department of Labor (and the corresponding Canadian authorities) and combine paid on-the-job training with classroom instruction.
Registered programs are registered either by DOL's Office of Apprenticeship or by a recognized State Apprenticeship Agency acting for DOL, depending on the state.
The day-to-day shape comes from each program's own standards.
The UA describes its registered apprenticeships as including 2,000 hours of paid on-the-job training per year plus 216 hours of related classroom instruction — the UA's page does not say whether the classroom figure repeats each year, so treat it as a detail to confirm with the local.
Federal registration rules set the floor underneath every registered program, union or not: an apprenticeable occupation must require at least 2,000 hours of on-the-job learning, DOL recommends — but does not require — a minimum of 144 hours of related technical instruction per year, and a program's probationary period may not exceed 25% of its length or one year, whichever is shorter, with probation counting toward completion.
How long it takes: the UA says its apprenticeships typically last five years, and SMART's ITI describes its sheet metal apprenticeships as four- or five-year programs.
What you finish with matters too.
Graduates receive a completion certificate from the registration agency — DOL's Office of Apprenticeship or the state apprenticeship agency.
That certificate is portable evidence of completed training, but it is not a trade licence: licensing is set at the state or local level, so completing an apprenticeship and holding a licence remain two different milestones.
Pay and benefits while you train
You are paid for the on-the-job half from your first day — that is what separates an apprenticeship from school.
Federal registration rules require registered programs to pay a progressively increasing wage schedule tied to skill, and the entry wage may not be below the federal minimum wage where it applies.
The federal rule sets no percentages: how big each raise step is, and how often it lands, is written into each program's own standards.
There is no standard union step schedule to quote, so be skeptical of any fixed percentage ladder you see online — your local's schedule is the only one that applies to you.
For context on how common union membership is around this trade: in 2025, 16.4% of employed wage-and-salary workers in construction and extraction occupations were union members, and 17.4% were represented by a union, per BLS.
In installation, maintenance and repair occupations — the BLS group that includes HVAC mechanics — 12.5% were members, and in the construction industry as a whole 11.1% were.
BLS's union tables cover broad occupation groups; the agency publishes no union-membership rate for HVAC technicians specifically, so treat any HVAC-specific union share you see quoted as unsourced.
On costs: SMART's ITI describes its sheet metal apprenticeships as combining on-the-job training and classes with little to no tuition.
Beyond tuition, what a program provides — benefits, pension contributions, tools, dues — varies by local, and our research did not confirm specific amounts for UA or SMART locals.
Whatever figure a website quotes belongs to someone else's local; ask yours what its current agreement actually provides.
For what apprentices earn across program types, and how raise schedules step up, see our HVAC apprentice pay guide — and the BLS-based tables on our HVAC apprentice salary page.
Application, test and interview
There is no national application form, no standard aptitude-test format and no uniform interview: application windows, testing and selection are set by each local's program, and they differ enough that two locals can run opposite intakes.
Two verified examples show the range.
In Indianapolis, Plumbers, Steamfitters & HVACR Service Technicians Local 440 JATC accepted apprenticeship applications year-round for the 2026-2027 program year.
In Albuquerque, UA Local 412's JATC releases applications only when its committee approves a new intake, and applicants call in during the last week of each month.
The lesson is not which pattern is typical — it is that your local's window is the only one that exists, and missing it can mean waiting for the next one.
The federal rules that apply everywhere are a baseline, not the bar.
A registered apprentice must be at least 16 years old unless a higher minimum is set by law, and there is no federal maximum age — registered programs may not discriminate against applicants aged 40 or older.
Individual programs can set additional qualifications on top, which is exactly why the local's own listing, not a national page, is the checklist that counts.
What happens between applying and your first day — the aptitude test, the interview, the ranking — is the JATC's own process.
Ask the local what its current process involves and what its program looks for; our general guide to getting an HVAC apprenticeship with no experience covers the preparation side of that.
Entry rules are local and they change — confirm before you apply
How competitive it is
An honest answer first: there is no reliable national figure for how hard it is to get into a union HVAC apprenticeship.
Acceptance rates, applicant counts and waitlist lengths are not published in any source our research could verify, and each local's intake is its own — so any national percentage you see quoted is not a number we can stand behind.
The realistic way to gauge your local is to ask it: how many apprentices it took in last cycle, when applications open next, and what the testing covers.
What the verified numbers do show is scale rather than selectivity.
The UA represents approximately 409,000 workers across North America, HVACR service technicians among them, and SMART's ITI reports more than 14,000 registered sheet metal apprentices in the US and Canada.
Both are counts of scale, not admissions odds.
The constraint is local: openings arrive when a JATC opens intake, so timing and geography decide far more than any national picture.
Practically: apply to more than one program rather than waiting on a single local.
Union programs are one part of the registered-apprenticeship landscape — our guide to HVAC apprenticeship programs covers all the types and how to find them in your state.
And whichever route you train, the same contractors hire for the same skills: browse HVAC apprentice jobs to see who is hiring near you.
Career information, not legal advice. Apprenticeship standards, entry requirements and pay schedules are set by each program's sponsor and its registration agency — the U.S. Department of Labor's Office of Apprenticeship or the state apprenticeship agency — so confirm the current details with the local you would apply to.