California has not passed a mileage tax. No state law requires drivers to pay a per-mile fee for road use, and no bill creating that requirement has reached the governor’s desk. What California has done is authorize research and voluntary pilot programs to test whether a per-mile road charge could someday replace the state gas tax. The most recent pilot finished in January 2025, and a final report to the legislature is due by December 31, 2026.1LegiScan. California SB339 – Chaptered
Until the legislature passes a new law, there is no fine, no penalty, and no enrollment requirement tied to a mileage-based fee. If you’ve seen a social media post claiming otherwise, it’s wrong.
What California Has Actually Passed
Three bills get mixed up in the rumor, and none of them created a mandatory mileage tax.
Senate Bill 1077, signed by Governor Brown in 2014, created a Road Usage Charge Technical Advisory Committee within the California Transportation Commission. The committee’s job was to study whether a per-mile fee could work as a gas tax alternative and to design a pilot program for testing it. The law called for a pilot, not a mandate.2California Legislative Information. California Vehicle Code 3090
The Road Repair and Accountability Act of 2017 (Senate Bill 1) raised the state gasoline tax by 12 cents per gallon and added new vehicle registration fees for road repairs. SB 1 had nothing to do with per-mile charges. It did introduce a $100 annual registration fee for zero-emission vehicles starting with model year 2020, which some drivers have confused with a mileage tax.3LegiScan. California SB1 – Transportation Funding
Senate Bill 339, passed in 2021, extended the road charge pilot through January 1, 2027, and expanded it to include an actual revenue collection test rather than only simulated billing. Participation stayed voluntary. SB 339 also set the December 31, 2026 deadline for the California State Transportation Agency to deliver a final report to the legislature on the pilot’s findings.1LegiScan. California SB339 – Chaptered
Nothing in any of these laws authorizes the state to charge or penalize a driver for not paying a per-mile fee. A mandatory program would need an entirely new bill.
What the Voluntary Pilot Has Tested
California has run two rounds of road charge testing, both voluntary and both aimed at research rather than revenue.
The first round, completed in 2017 under SB 1077, enrolled more than 5,000 vehicles that collectively reported over 37 million miles across nine months. That round used simulated invoices and mock payments, with no real money changing hands.4LegiScan. California AB1421 – Introduced
The second round, the Road Charge Collection Pilot, ran from August 2024 through January 2025 under SB 339. Caltrans administered this phase and tested actual revenue collection mechanics.5California Road Charge. Road Charge Collection Pilot Volunteers had to own a California-registered vehicle and agree to share driving data for the duration of the test.
Volunteers in the pilot were split into two groups. One paid a flat per-mile rate set by the Technical Advisory Committee. The other paid an individually calculated rate equal to the state gasoline excise tax divided by their vehicle’s EPA fuel economy rating.1LegiScan. California SB339 – Chaptered California’s state gasoline excise tax is currently 61.2 cents per gallon.6California Department of Tax and Fee Administration. Fuel Taxes A car rated at 30 miles per gallon would owe about 2 cents per mile under that formula; a 20 mpg vehicle, about 3 cents.
The pilot was also built so drivers who buy gasoline don’t pay twice. When a per-mile charge is calculated, the system subtracts what the driver already paid through the state fuel excise tax. If the mileage charge comes out lower than the gas tax already paid, the driver receives a credit.
Any actual per-mile rate for a future mandatory program would be set by the legislature, not by the pilot administrators. The rates used in the pilot apply only to the volunteers who signed up for it.
What EV Owners Already Pay
California does not wait for a mileage tax to collect road funding from electric vehicle owners. Under SB 1, owners of zero-emission vehicles from model year 2020 and later pay an annual Road Improvement Fee at registration. The fee started at $100 and has been adjusted for inflation; it currently sits at $121.7California DMV. Registration Fees
This flat fee is not a mileage tax. A driver who puts 5,000 miles a year on an EV pays the same $121 as someone driving 25,000 miles. If California eventually adopts a road charge, the existing ZEV registration fee would likely be restructured or eliminated to avoid stacking fees on the same drivers, though that decision would also sit with the legislature.
What Could Happen Next
The road charge pilot program’s statutory authority expires on January 1, 2027, unless the legislature extends it.1LegiScan. California SB339 – Chaptered Before that date, the California State Transportation Agency must deliver its final report to the legislature by December 31, 2026, covering findings from both the 2017 simulation and the 2024-2025 collection pilot along with recommendations on whether and how to proceed.
From there, lawmakers have a few options. They could extend the pilot for more testing. They could pass a mandatory road charge for certain vehicle classes, most likely starting with EVs, as other states have done. They could also drop the concept.
Any mandatory program would require a new bill to pass both chambers of the legislature and receive the governor’s signature. Because the final report has not yet been delivered, a statewide mandatory mileage tax is at least one full legislative session away, and likely further. If a specific effective date starts circulating before any bill has even been introduced, treat the claim with skepticism.
The Bottom Line for Drivers Today
If you drive a gasoline vehicle in California, you pay the state excise tax at the pump and nothing else tied to miles driven. If you drive a 2020-or-newer zero-emission vehicle, you pay the $121 annual Road Improvement Fee at registration, regardless of how far you drive. No one in California owes a per-mile road charge unless they volunteered for the pilot program, and that pilot is now closed. Whether that changes depends on what the legislature does after the December 2026 report lands.