California New Truck Law: Fleets Covered, Exemptions, Penalties

California’s new truck law is actually two connected California Air Resources Board (CARB) rules: the Advanced Clean Trucks (ACT) regulation, which forces manufacturers to sell a rising share of zero-emission medium- and heavy-duty trucks in the state starting with model year 2024, and the Advanced Clean Fleets (ACF) regulation, which requires larger fleet owners to replace diesel trucks with zero-emission alternatives on a set schedule. Together they cover Class 2b through Class 8 vehicles, from heavy-duty pickups to full 18-wheelers, and both aim at 100 percent zero-emission new sales by model year 2036.¹ The rules apply to trucks operating in California, not just those registered there, and CARB is enforcing them at the state level even as parts of the federal authority behind them are contested.

Where Federal Challenges Stand

California’s ability to set its own vehicle emission standards runs through a Clean Air Act waiver from the U.S. Environmental Protection Agency. The EPA granted a waiver for the ACT manufacturer sales rule in April 2023. The ACF fleet purchase rule followed a different path: CARB withdrew its federal waiver request in January 2025.²

In May 2025, the U.S. Senate voted to revoke two EPA waivers tied to California’s heavy-duty truck standards. If the House follows and the President signs, those waivers would be formally withdrawn, which could limit California’s ability to enforce the manufacturer sales mandate and block other states from adopting matching rules. CARB continues to enforce its regulations at the state level in the meantime. Fleet owners operating in California should treat the rules as active while watching federal developments before committing to large purchases.

Which Fleets Are Covered

The ACF regulation sorts affected operators into categories, and the strictest requirements apply to “high-priority fleets.” A fleet is high-priority if it owns or dispatches 50 or more trucks, or generates $50 million or more in annual gross revenue. Federal government fleets fall into the same category no matter their size or revenue. State and local government fleets are on a separate track with slightly later deadlines.³

Fleets under both the 50-vehicle and $50-million thresholds are not subject to the ACF purchase mandates directly. They are still affected, because the ACT sales rule shrinks the supply of new diesel trucks year by year until it disappears. Smaller operators running heavy-duty trucks in California also fall under the Clean Truck Check inspection program covered below.

Coverage extends to Class 2b through Class 8 vehicles based on the manufacturer’s gross vehicle weight rating. Because the rules apply to vehicles operating in California rather than only those registered there, out-of-state carriers that regularly dispatch trucks into the state need to evaluate whether their California-operating vehicles pull them into compliance obligations. Trucks temporarily entering the state to support a declared emergency are exempt during the response period.

Drayage Truck Deadlines

Drayage trucks serving California’s seaports and intermodal railyards face the tightest schedule. Since January 1, 2024, only zero-emission drayage trucks can be newly registered in CARB’s online system. Diesel and natural gas drayage trucks already registered by December 31, 2023, are classified as “legacy” vehicles and can keep operating through their useful life.⁴

Starting in 2025, legacy drayage trucks 12 years or older must report mileage annually and drop out of the registry once they pass useful life. By January 1, 2035, all drayage trucks entering seaports and intermodal railyards must be zero-emission regardless of remaining useful life. That 2035 date is a hard cutoff with no further extensions available for combustion-powered drayage trucks.⁴

How High-Priority Fleets Comply

High-priority and federal fleet owners choose between two compliance paths. Both end at the same place; they differ in how flexibility works along the way.

Model Year Schedule

Under this path, only zero-emission vehicles (or qualifying near-zero-emission plug-in hybrids) can be added to California operations starting January 1, 2024. Every new purchase, lease, or transfer into the state fleet must be zero-emission. Existing combustion trucks stay in service until they reach the end of their useful life and are then retired. Beginning with model year 2036, near-zero-emission vehicles no longer count, and only full zero-emission vehicles qualify.³

ZEV Milestones Option

This alternative lets a fleet owner decide which specific trucks to replace and when, so long as the overall fleet hits escalating zero-emission percentage targets by set compliance years. The benefit is operational: you can replace vehicles that have good zero-emission substitutes first and keep specialized combustion trucks longer. The catch is that the percentage floors ratchet up annually, and slipping behind gets harder to recover from each year.

Useful Life for Combustion Trucks

Under either path, a combustion truck’s useful life sets its exit date. Every truck gets a minimum of 13 years from its engine certification model year, even if it has already exceeded 800,000 miles. After 13 years, the truck can keep operating until it reaches either 18 years from certification or 800,000 miles, whichever comes first.⁵

What Manufacturers Have to Sell

The ACT rule works on the supply side. Manufacturers selling medium- and heavy-duty vehicles in California must make a rising share of those sales zero-emission each model year, climbing to 100 percent by model year 2036.¹

The percentages differ by weight class. Larger trucks in Class 4–8 face steeper early targets than Class 2b–3. For 2026, roughly 10 to 13 percent of a manufacturer’s California sales in these classes must be zero-emission depending on weight category. By 2030, targets rise to 30 to 50 percent. Class 7–8 tractors sit at 40 percent from 2033 through 2035 before the universal 100 percent requirement in 2036.⁶ For a fleet owner, this matters even if you are below the ACF thresholds, because the diesel truck you plan to buy in a few years may simply not be for sale.

Clean Truck Check Applies to Almost Everyone

Separately from the ACF fleet purchase rules, California runs a Clean Truck Check inspection program that covers nearly all diesel and alternative-fuel trucks with a gross vehicle weight rating over 14,000 pounds operating in the state. That includes trucks registered outside California that regularly cross state lines.⁷

The program has three parts: register the vehicle in CARB’s Clean Truck Check database, pay the $30 annual per-vehicle compliance fee, and submit a passing emissions test done by a credentialed tester. Testing data must be submitted within 90 days before the vehicle’s registration deadline. If a truck is not marked compliant in CARB’s system, the California DMV blocks registration renewal. The block lifts automatically once CARB confirms compliance.⁷

Annual Reporting Through TRUCRS

Fleet owners under the ACF regulation report through the Truck Regulation Upload, Compliance and Reporting System (TRUCRS). High-priority and federal fleets file by February 1 each year; state and local government fleets file by April 1.⁸

Each vehicle report must include the VIN, the engine family name shown on the emission control label, the gross vehicle weight rating, and the primary fuel type. The emission control label is normally on the engine block or inside the hood. Some vehicles also need odometer or hubodometer readings, including backup vehicles, trucks operating under an exemption, and tractors with engines 12 years old or older. If a backup vehicle exceeds its allowable mileage limit, the change must be reported within 30 calendar days.

Accuracy is not optional. CARB cross-checks submitted data against engine certification records, and mismatched entries can get filings rejected. Verify the emission control label physically on each truck rather than trusting internal records, especially for older units that may have had engine replacements. Update the portal whenever a vehicle enters or leaves the fleet.

Exemptions and Extensions

CARB built several relief valves into the ACF regulation for situations where buying a zero-emission truck is genuinely not possible. Each requires documentation and CARB approval.

ZEV Purchase Exemption

If no zero-emission truck exists in the same configuration as the vehicle being replaced, the fleet owner can request permission to buy a new combustion truck. “Same configuration” is the operative phrase: the owner must show that no manufacturer offers a zero-emission model matching the required body type, weight class, and operational specifications.⁹

Daily Usage Exemption

When a zero-emission truck exists in the right configuration but cannot handle the required daily workload because of range or payload limits, the fleet owner can apply for this exemption. Approval requires mileage and usage logs showing that no available zero-emission option can meet the documented daily duty cycle, and the fleet must already be at least 10 percent zero-emission before qualifying.¹⁰

Infrastructure Delay Extension

Fleet owners who have begun installing charging or hydrogen fueling infrastructure and hit construction or utility delays beyond their control can request a time extension. The project must have started at least one year before the next compliance deadline. A construction delay extension can run up to two years; a site electrification delay extension can stretch up to five years depending on documentation.¹⁰ Applicants submit executed contracts, utility applications, and written documentation from the contractor, utility, or building department explaining the cause of the delay.¹¹

Backup and Emergency Vehicles

A truck driven fewer than 1,000 miles per year can be designated as a backup vehicle and excluded from zero-emission compliance entirely. The designation must be registered in TRUCRS at the start of each compliance year, and miles driven during a declared emergency do not count against the cap. Used combustion trucks can be bought and immediately designated as backup vehicles without breaking compliance.¹⁰ Vehicles deployed under contract to support a declared emergency are temporarily removed from the California fleet for compliance purposes, and TRUCRS reporting is waived during the response period as long as the operator has proof of the contract with the emergency management agency.

Money to Offset the Cost

The price gap between zero-emission and diesel trucks is real, and several programs can narrow it.

California HVIP Vouchers

The Hybrid and Zero-Emission Truck and Bus Voucher Incentive Project (HVIP) provides point-of-sale vouchers that reduce the purchase price of qualifying zero-emission vehicles. For a Class 8 battery-electric truck, the base voucher is $120,000, with small businesses eligible for up to $330,000. Drayage and refuse haulers get higher base vouchers of $150,000, and hydrogen fuel cell Class 8 trucks qualify for $240,000 to $300,000 depending on the application.¹² Funding availability moves; check the HVIP portal before placing an order.

Federal Tax Credit (Section 45W)

Under Internal Revenue Code Section 45W, a business buying a qualifying commercial zero-emission vehicle can claim a federal tax credit equal to 30 percent of the vehicle’s cost or the incremental cost over a comparable diesel vehicle, whichever is less. The credit caps at $7,500 for vehicles under 14,000 pounds GVWR and $40,000 for heavier vehicles. The vehicle must be subject to depreciation and acquired for business use, not resale. The credit is available for vehicles placed in service through the end of 2032.¹³

EPA Clean Heavy-Duty Vehicles Grant Program

The federal EPA Clean Heavy-Duty Vehicles Grant Program funds replacement of older trucks with zero-emission alternatives and can cover vehicle purchases, charging or fueling infrastructure, and workforce training. The program prioritizes projects in areas that do not meet federal air quality standards.¹⁴

Penalties for Noncompliance

CARB’s main enforcement lever is the DMV registration system. The California DMV database connects to CARB’s compliance records, and if a truck is not marked as compliant, DMV software blocks the registration process. No tags issue and no renewal goes through until the vehicle satisfies CARB’s requirements. A truck that cannot be registered cannot legally operate on California roads, so noncompliance is operationally severe rather than a paper fine.

CARB also has authority to impose civil penalties under the California Health and Safety Code. Penalties can reach up to $10,000 per vehicle per day of noncompliance, though the actual amount depends on the severity and duration of the violation. Fleet owners who find they are out of compliance are generally better off contacting CARB proactively, as the agency has historically been more accommodating with self-reporters than with operators caught in enforcement actions.

1
California Air Resources Board. Zero-Emission On-Road Medium-and Heavy-Duty Strategies
2
US EPA. Vehicle Emissions California Waivers and Authorizations
3
California Air Resources Board. Advanced Clean Fleets
4
California Air Resources Board. Advanced Clean Fleets Drayage Truck Regulation Overview
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California Air Resources Board. Drayage Truck Minimum Useful Life Factsheet
6
California Air Resources Board. Path to Zero Emission Trucks FAQ
7
California Air Resources Board. Clean Truck Check (HD I/M)
8
California Air Resources Board. High Priority and State and Local Government Fleet Reporting Guidance
9
California Air Resources Board. Advanced Clean Fleets Regulation – Zero-Emission Vehicle Purchase Exemption
10
California Air Resources Board. Advanced Clean Fleets Regulation Exemptions and Extensions Overview
11
California Air Resources Board. ZEV Infrastructure Delay Extension Checklist
12
California Hybrid and Zero-Emission Truck and Bus Voucher Incentive Project. Funding – Clean Truck and Bus Voucher Incentive Project
13
Office of the Law Revision Counsel. 26 USC 45W Credit for Qualified Commercial Clean Vehicles
14
US EPA. Clean Heavy-Duty Vehicles Grant Program Awards