If you last looked into California's CARB regulations in 2024, a lot has changed. The sweeping ZEV mandates that had fleet managers bracing for forced electric transitions? Largely off the table for private fleets. But the compliance program that actually has teeth right now — Clean Truck Check — is entering its enforcement phase, and the consequences for ignoring it are real.

Here's where things stand in 2026

The Big Shift: The Private Fleet ZEV Mandate Is Effectively Dead

The regulation that caused the most anxiety was the Advanced Clean Fleets (ACF) rule — the one that would have required high-priority private fleets to hit ZEV purchase targets on an aggressive timeline. That rule has been gutted.

CARB withdrew its Clean Air Act waiver request after it became clear the federal administration wouldn't support California's authority to set its own ZEV standards. Without that waiver, the ACF couldn't be enforced on private or federal fleets. In September 2025, CARB voted to formally repeal the High Priority Fleet and Drayage Fleet provisions of the ACF, with the repeal taking effect January 1, 2027.

What this means: if you operate a private commercial fleet, you are no longer on the hook for ZEV purchase mandates under ACF. The 2036 all-ZEV sales requirement for manufacturers is also on hold pending a federal waiver that isn't coming anytime soon.

The exception: State and local government fleets. ACF still applies to them, with some added flexibility — the 50% ZEV purchase requirement has been pushed back three years, and the 100% ZEV purchase deadline is now 2030.

What's Very Much Still in Effect: Clean Truck Check

Don't mistake the ACF rollback for a regulatory free pass. Clean Truck Check — CARB's Heavy-Duty Inspection and Maintenance program — is active, enforced, and tightening.

Here's what the program requires:

• Registration of all subject vehicles in CARB's Clean Truck Check database (CTC-VIS)
• Annual compliance fee of $32.13 per vehicle (updated January 1, 2026)
• Bi-annual emissions testing by a CARB-credentialed tester, with passing results submitted to CARB

The program applies to nearly all diesel and alternative-fuel heavy-duty vehicles with a GVWR over 14,000 pounds operating on California public roads — including vehicles registered outside California.

That last point matters. If your fleet operates in California but is registered elsewhere, you are still subject to Clean Truck Check. CARB reconfirmed this in a March 2026 posting. Out-of-state registration is not an exemption.

2026–2027: Enforcement Is Active

Clean Truck Check has been phasing in since 2023. Here's where things stand now:

2023–2024: Roadside monitoring and database registration requirements rolled out

2025: Bi-annual testing submissions required; DMV registration holds began for non-compliant vehicles

2026–2027: Active enforcement phase — fines are now being issued to fleets that haven't complied with the testing schedule

2028: Testing frequency increases to four times per year for OBD-equipped vehicles

If your fleet hasn't been actively managing this, now is the time. Non-compliant vehicles face fines, DMV registration holds, and potential denial of access at California ports and railyards.

What Compliance Actually Looks Like

For most fleets, Clean Truck Check compliance breaks down into four ongoing tasks:

1. Register vehicles in CTC-VIS. Every subject vehicle needs to be in CARB's system with accurate owner and vehicle information. Updates are required within 30 days of any purchase or sale.
2. Pay the annual fee. $32.13 per vehicle, due based on each vehicle's compliance deadline. Payment must be made through CTC-VIS — payments made through other CARB portals don't count.
3. Schedule bi-annual emissions testing. Testing must be performed by a CARB-credentialed tester using an approved device. You can test up to 90 days before the deadline. Deadline timing varies: California-registered vehicles are based on DMV registration expiration; out-of-state vehicles are based on the last digit of the VIN.
4. Submit passing test results. Results must be submitted by the credentialed tester through CTC-VIS. A compliance certificate is issued once payment and testing are confirmed.

Failure to submit results by the deadline results in a CARB hold — which blocks DMV registration renewal.

Why Fleet Scale Makes This Harder

Managing one or two trucks through this process is straightforward. Managing 50, 500, or 5,000 vehicles across multiple states — some registered in California, some not, all with different testing deadlines — is a different problem entirely.

Each vehicle has its own compliance timeline. Deadlines are staggered. Missing one doesn't just mean a fine for that vehicle; it can mean a registration hold that pulls a revenue-generating asset off the road.

This is where fleet management infrastructure pays for itself. Tracking Clean Truck Check deadlines across a large mixed fleet, flagging upcoming testing windows, and maintaining accurate CTC-VIS records is exactly the kind of compliance overhead that fleet management partners are built to handle.

The Bottom Line

The CARB story in 2026 is more nuanced than most 2024 coverage could’ve predicted. The electric mandate panic for private fleets has subsided, but the compliance work hasn't. Clean Truck Check is real, it's enforced, and it applies to any fleet operating in California regardless of where your vehicles are registered. If your fleet even visits California and you haven't built Clean Truck Check into your compliance calendar, that's the first thing to fix.

Questions about managing fleet compliance across multiple regulations and states? Talk to an EMKAY fleet specialist.