California’s Low Carbon Fuel Standard is a market-based program run by the California Air Resources Board (CARB) that scores every transportation fuel sold in the state by its lifecycle carbon intensity, then forces that score down year after year by making cleaner fuels earn tradeable credits and dirtier fuels generate deficits that must be retired.1California Air Resources Board. AB 32 Global Warming Solutions Act of 2006 Amendments that took effect on July 1, 2025 sharply steepened the trajectory: a 30 percent reduction in the carbon intensity of California’s fuel pool by 2030, and a 90 percent reduction by 2045, both measured against a 2010 baseline.2California Air Resources Board. CARB Updates the Low Carbon Fuel Standard to Increase Access to Cleaner Fuels and Zero Emission
What Changed in 2025
The prior version of the program capped out at a 20 percent reduction target in 2030 with nothing scheduled after that. The 2024 amendments replaced that flat finish with a much longer and steeper runway.3California Air Resources Board. Proposed Low Carbon Fuel Standard Amendments The revised rule dropped the annual carbon intensity benchmark by 9 percent in 2025 as an immediate step-down, then set steeper annual reductions to begin in 2031.
The amendments also added an automatic acceleration mechanism, effective starting in 2028. If the ratio of banked credits to annual deficits exceeds three-to-one, the entire reduction schedule shifts forward by one year. CARB built this trigger to draw down a surplus of roughly 38 million credits that had accumulated under the older targets. It can fire only once per year, but the effect compounds if the surplus persists.
How Carbon Intensity and Credits Work
Every fuel pathway in the program receives a carbon intensity score in grams of carbon dioxide equivalent per megajoule (gCO2e/MJ). The score covers the fuel’s full lifecycle: feedstock production or extraction, processing, transport into California, and combustion. CARB calculates these scores using its California-modified GREET model, which reflects regional production methods, feedstock types, and energy inputs for each pathway.4California Air Resources Board. LCFS Pathway Certified Carbon Intensities
Two renewable natural gas providers can have very different scores depending on their feedstock. Some dairy-derived biomethane pathways come out with negative carbon intensity, meaning their lifecycle emissions reductions exceed the emissions from combustion.
Each year, the allowable benchmark drops. A fuel scoring below the benchmark earns credits proportional to the gap; a fuel scoring above it generates deficits. Deficit holders must retire enough credits to offset their annual deficits, either credits they earned themselves or credits purchased from other market participants.
Who Has to Participate
The rule identifies “fuel reporting entities” as the companies obligated to track and report every unit of transportation fuel they bring into the California market. For gasoline and diesel, that’s the producer or importer. When a blended fuel contains both a fossil and a renewable component, each component’s producer or importer reports separately.5Legal Information Institute. California Code of Regulations Title 17 95483 – Fuel Reporting Entities For gaseous fuels like compressed natural gas or hydrogen, biomethane producers or importers report the renewable portion, and the owner of the fueling equipment typically reports the fossil portion.
These entities automatically become credit or deficit generators depending on what they supply. On the other side of the market, providers of low-carbon energy like electricity, hydrogen, and renewable natural gas can voluntarily opt in as credit generators.6Legal Information Institute. California Code of Regulations Title 17 95483.2 – LCFS Data Management System Opting in lets them earn credits for every unit of clean energy delivered and sell those credits to deficit holders. That’s the financial pull the program uses to bring cleaner fuels into the state.
Reporting and Verification
Fuel reporting happens on a quarterly cycle through the LRT-CBTS, CARB’s online reporting and credit transfer platform. Transaction data for each quarter must be uploaded within 45 days after the quarter closes, with an additional 45 days for reconciliation with business partners.7Legal Information Institute. California Code of Regulations Title 17 95491 – Fuel Transactions and Compliance Reporting An annual compliance report covering the full prior calendar year is due April 30, and reconciles the year’s total credits and deficits.8California Air Resources Board. Low Carbon Fuel Standard Reporting, Verification and Annual Compliance Calendar Entities active in the Credit Clearance Market must file an amended annual report by August 31.
CARB does not take participants at their word. Reported data must be independently verified by accredited verification bodies, and individual verifiers must also hold personal CARB accreditation.9California Air Resources Board. LCFS Verification Verifiers cannot have current or past business relationships that create a conflict of interest with the entity they audit. Starting with the 2026 reporting year, annual reports generating electric vehicle credits also must be independently verified. The full verification cycle typically runs about 90 days, and verification statements for 2026 operating data are due by August 31, 2027.
Credit generation itself requires more than registration. Fuel providers must apply for certified pathways by submitting engineering data, feedstock sourcing records, and production process documentation. For each batch, they need volume measurements, feedstock identification, and chain-of-custody records including bills of lading, invoices, and production logs. Weak documentation is where most compliance problems start, and CARB can deny credit applications or impose fines when the data doesn’t hold up.
The Credit Market and Its Price Cap
Once CARB issues credits into a participant’s account, they can be held for future compliance or sold through the LRT-CBTS. Both parties must confirm transaction details electronically before credits transfer between accounts. Prices move with supply and demand. In March 2026, the average credit transfer price was roughly $66 per metric ton of CO2 equivalent, with individual trades ranging from about $55 to $72.10California Air Resources Board. Weekly LCFS Credit Transfer Activity Reports Those prices sat well below historical highs, largely because the surplus built up under the old targets was still working through the market.
For deficit holders that cannot retire their obligations through normal trading, the program includes a Credit Clearance Market that opens annually. The maximum credit price in the Credit Clearance Market for 2026 is $275.39 per metric ton, based on a $200 baseline set in 2016 and adjusted annually by the Consumer Price Index.11California Air Resources Board. LCFS Credit Clearance Market Open-market prices have historically traded well below this cap, but the ceiling gives deficit holders a worst-case compliance cost.
Penalties for Noncompliance
CARB enforces the program under California Health and Safety Code Section 38580, which treats violations of AB 32 programs the same as emissions of air contaminants for penalty purposes. Each day a required report is unsubmitted, incomplete, or inaccurate counts as a separate violation. Each unretired deficit at the end of a compliance period also counts as a separate day of violation, subject to a penalty of up to $1,000 per deficit.12California Air Resources Board. Low Carbon Fuel Standard Final Regulation Order For a large importer carrying thousands of unretired deficits, per-deficit penalties add up quickly.
CARB can also seek injunctive relief, impose corrective action plans, and subject noncompliant entities to enhanced reporting and auditing. Persistent noncompliance can suspend fuel pathway certifications and trading privileges, locking a company out of the market until it resolves its outstanding obligations.
How It Fits with Federal Programs
The LCFS runs alongside the federal Renewable Fuel Standard (RFS), and fuels that generate LCFS credits typically also generate Renewable Identification Numbers (RINs) under the RFS. Producers of biomass-based diesel, ethanol, renewable natural gas, and other qualifying fuels can earn value from both simultaneously, because the two programs measure different things: RFS imposes volumetric blending requirements on refiners, while LCFS targets carbon intensity reduction regardless of volume.
The federal Section 45Z Clean Fuel Production Credit, which replaced the older blender’s tax credit, adds a third stream. The 45Z credit uses its own emissions model but recognizes CARB LCFS verifiers as qualified certifiers for lifecycle emissions determinations. How 45Z interacts with LCFS credit values is still developing as the IRS finalizes its rulemaking, so producers evaluating project economics should plan for all three incentive streams and confirm current federal guidance before locking in assumptions.