IRA prevailing wage rules for California contractors
The Inflation Reduction Act ties a bigger federal tax credit to a prevailing wage and apprenticeship rule for laborers and mechanics, set out by the IRS and the Department of Labor at irs.gov/pwa. It is a federal tax law condition, tied to who claims a credit, not California's own public works prevailing wage law, and a job can owe one, the other, or both.
What this requirement actually is
To claim the larger version of certain clean energy tax credits and deductions, generally 5 times the base amount, a taxpayer has to show that laborers and mechanics who built, altered, or repaired the facility were paid at least the prevailing wage rate, and that a minimum share of the labor hours went to registered apprentices, under the IRS overview of the prevailing wage and apprenticeship (PWA) requirements. The taxpayer, usually a solar developer, building owner, or a public agency using the elective pay option covered below, has to prove it, and the proof comes from payroll: hours by classification, wages, fringe benefits, and apprentice ratios for every contractor and subcontractor on the job. If you do the HVAC, electrical, or solar work, that proof runs through your payroll even though you never file for the credit.
Which credits and deductions carry the requirement
The IRS lists twelve code sections carrying the PWA condition, each with its own base rate and PWA rate. The ones a California trade contractor is most likely to see:
| Credit or deduction | What it covers | Base rate | Rate with PWA met |
|---|---|---|---|
| Energy Efficient Commercial Buildings Deduction (179D) | Interior lighting, HVAC, hot water, or building envelope work | $0.50 to $1 per square foot | $2.50 to $5 per square foot |
| Investment Tax Credit for Energy Property (48) | Solar, energy storage, geothermal, small wind, combined heat and power | 6% of qualified investment | 30% of qualified investment |
| Clean Electricity Investment Tax Credit (48E) | Same categories, facilities placed in service after 2024 | 6% of qualified investment | 30% of qualified investment |
| Alternative Fuel Vehicle Refueling Property Credit (30C) | EV charging and refueling equipment in eligible areas | 6% of basis | 30% of basis |
| New Energy Efficient Homes Credit (45L) | New energy efficient homes and qualifying multifamily units | $500 to $1,000 per unit | $2,500 to $5,000 per unit |
The same source also lists 45, 45Y, 45Q, 45U, 45V, 45Z, and 48C. Apprenticeship does not apply to 45L or 45U, but the wage half still does.
When it applies
Two carve-outs let a taxpayer claim the full rate without meeting PWA at all. Work performed before January 29, 2023 is not subject to the requirement, and neither is a facility, energy project, or storage technology under one megawatt claiming credits 45, 45Y, 48, or 48E, per the IRS overview. Outside those two exceptions, the requirement runs for the life of the construction, alteration, or repair work on the facility, not just the day the credit is claimed.
How the wage rate is set
The Department of Labor sets the prevailing wage rate for each labor classification, by county and type of construction, the same Davis-Bacon mechanism used on federal contracts. Rates are published as general wage determinations at sam.gov/content/wage-determinations, according to DOL's IRA page. If no determination covers your county and craft, request one by emailing IRAprevailingwage@dol.gov, ideally no more than 90 days before construction starts.
The apprenticeship rule
- Any taxpayer, contractor, or subcontractor employing 4 or more workers on the facility must employ at least one qualified apprentice from a registered program.
- A minimum share of total labor hours must go to apprentices: 10% for construction beginning before 2023, 12.5% beginning in 2023, and 15% for construction beginning in 2024 or later.
- The apprentice-to-journeyworker ratio set by the registered apprenticeship program itself still applies on top of the percentage.
- A good faith effort exception applies if a registered program is asked for apprentices and none are available, or the program does not respond.
All four points come from the IRS PWA overview. This is separate from California's own DAS 140 and DAS 142 process, which runs off a labor hour ratio rather than a fixed percentage. A project owing both has to satisfy both apprenticeship tests for the same workers.
What it costs to get wrong
For a wage shortfall, the taxpayer pays the worker the difference owed plus interest at the federal short-term rate plus 6 percentage points, and pays the IRS a $5,000 penalty per underpaid laborer or mechanic, per the IRS FAQ on PWA requirements. An apprenticeship shortfall costs $50 per labor hour missed, $500 per hour for intentional disregard. Intentional disregard also raises the wage-side amounts, per the IRS overview, though it does not state the exact figure. A qualifying project labor agreement removes all of these penalties.
The records you will actually be asked for
The taxpayer files Form 7220, Prevailing Wage and Apprenticeship (PWA) Verification and Corrections, one per facility, and it is built entirely from contractor and subcontractor payroll: laborers and mechanics per classification, total hours per classification, total wages, total bona fide fringe benefits, and qualified apprentice hours, per the Form 7220 instructions. You do not file this form yourself, but the developer or general contractor claiming the credit will come to you for these numbers, and they are the same hours-by-classification, wage, and fringe data a certified payroll export already tracks. See our fringe benefit statement guide for how the fringe number gets built.
Not the same law as California's own prevailing wage requirement
California's prevailing wage duty turns on public funding: any construction contract over $1,000 paid in whole or in part with public funds, under Labor Code 1720, owes the state's eCPR filing regardless of any tax credit. The IRA's requirement turns on something else: whether a taxpayer is claiming an increased federal credit. A privately owned building claiming the 179D deduction has no public funding and never touches California's public works law, but it still owes the federal PWA paperwork. Our federal vs state certified payroll guide covers the more common overlap, Davis-Bacon and California law on the same public job.
The two can also stack. A school district or city can use elective pay under IRC section 6417 to receive the credit as a direct IRS payment, and the same FAQ confirms PWA requirements still control the amount. That FAQ limits elective pay to a specific list of applicable credits, and 179D is a deduction, not one of them, so a plain HVAC retrofit does not qualify for elective pay. A public agency installing solar or a geothermal heat pump system claimed under section 48 or 48E through elective pay runs California's public works law and the federal IRA requirement on the same contract, two proofs from the same hours.
What to do if a job carries this requirement
- Ask whether the project is claiming an increased credit under any section above, and get the wage determination in writing before you start.
- Track hours by labor classification if your own categories do not already match the determination's.
- Check whether the job is also California public works. If so, you owe the state's own certified payroll filing on top of the federal PWA data.
- Keep hourly rates, hours, classification, deductions, and wages paid on file. The taxpayer's compliance rests on records you control.