California Department of Motor Vehicles has announced that the federal regulations that allowed states to issue Clean Air Vehicle decals will expire on Sept. 30.

Putting the brakes on this program means that starting Oct. 1, the decals will no longer be valid in California, or elsewhere in the United States. All vehicles will be required to meet posted vehicle occupancy to travel in carpool lanes and pay required tolls or risk receiving a citation.

While Clean Air Vehicle decals were good for up to four years, the federal government’s decision not to extend the program makes all decals invalid as of Oct. 1, regardless of the date they were issued.

With the end of this federal program, the DMV can no longer issue Clean Air Vehicle decals that allow vehicles to travel in carpool lanes with only one occupant. DMV stopped processing new Clean Air Vehicle decals after Aug. 29.

“This is a great program for climate-conscious Californians,” said Director Steve Gordon. “We have issued over one million decals since this program was approved, which has helped to foster a change in how we drive. Californians are committed to lowering their carbon footprint and these decals helped drivers be good stewards of our highways and environment. By taking away this program, hundreds of thousands of California’s drivers will pay the price. It’s a lose-lose and we urge the federal government to retain this program.”

DMV offices are displaying information about the end of the federal Clean Air Vehicle decal program and a notice has been posted on the DMV website. The DMV will directly notify customers who have an email address on file with the department. In addition, social media posts will remind customers of the program’s expiration.

To inform drivers of this change, Caltrans will post the following messaging on its electronic road signage:

“CLEAN AIR DECALS

NOT VALID

STARTING OCT. 1”

HOV lane access for single-occupant clean vehicles in California was first authorized in 1999, with the most recent reauthorization of the program coming in 2017. The California DMV began issuing Clean Air Vehicle decals to qualifying vehicles under the current program on Jan. 1, 2019.

Clean Air Vehicle decals expired on Jan. 1 of the fourth year after they were issued. This means they would have been valid for three full years, plus any additional months during the year they were issued.

For example, if a Clean Air Vehicle decal was issued at any time in 2021, it expired on Jan. 1, 2025. Now, all Clean Air Vehicle decals will be invalid as of Oct. 1, 2025.