IFTA Tax Rates in Louisiana (2026)

Key numbers at a glance

Louisiana is where the fuel comes from. Refinery rows along the Mississippi between Baton Rouge and New Orleans supply a big share of the diesel burned in the South, and the state taxes every gallon of it at the same flat rate whether it stays home or crosses the line on I-10, I-20 or I-49. Per the Louisiana Department of Revenue, gasoline, diesel and special fuels are all taxed at $0.20 per gallon — special fuels covering CNG and LNG on a gallon-equivalent basis too.

That rate keeps Louisiana near the bottom of the national table. The Tax Foundation's July 2026 accounting puts the state's combined gasoline tax at about 20.9 cents once small variable components are included — among the ten lowest rates in the country. For IFTA purposes the reportable number is the flat 20 cents, which makes Louisiana one of the few states where the rate requires no mental math at all: miles divided by MPG, times twenty cents, done. See how that stacks up nationally on the IFTA rates by state hub.

IFTA tax rates in Louisiana

Per the Louisiana Department of Revenue. Rates as of Q4 2026 — confirm the current official IFTA matrix before filing.

The gap between the 20-cent excise and the roughly 20.9-cent combined figure is the small variable piece tracked by national comparisons — rounding-level money on any single fill. What matters for planning is the headline: Louisiana taxes diesel at exactly one dollar per five gallons, and nothing about the rate moves with inflation or wholesale prices as it does in Kentucky, Maryland or Illinois.

Fueling strategy: Louisiana versus its neighbors

Three land borders, all slightly more expensive on diesel. Rates below are from the current IFTA matrix (as of Q4 2026 — confirm the current official IFTA matrix).

Texas matches Louisiana nickel-for-nickel at 20 cents, so the state line on I-10 is tax-neutral — buy wherever the pump price net of tax is lowest. Eastbound toward Mississippi (24 cents) and northbound toward Arkansas (28.5-cent diesel) is where the arithmetic favors loading up before you leave: 8.5 cents a gallon against Arkansas adds up to about $10 on a 120-gallon fill. The bigger edge is often pre-tax price rather than tax — Louisiana and Texas pump prices near the Gulf are frequently the cheapest on a southern run, so the low rate and the cheap base price compound. Just price out-of-route miles before chasing a cross-border stop; our deadhead miles guide shows the break-even math, and the IFTA calculator turns any route into per-state tax lines.

How Louisiana IFTA affects your filings

Louisiana-based carriers license and file quarterly through the Louisiana Department of Revenue; pass-through carriers carry Louisiana lines on their base-state return at the same 20-cent rate. The arithmetic: taxable gallons equal Louisiana miles divided by truck MPG, times $0.20. Drive 400 Louisiana miles at 6.5 MPG and you burn 61.5 gallons — 61.5 times $0.20 is $12.30 of Louisiana fuel tax. Total every jurisdiction, subtract the tax embedded in your pump receipts, and the net is what you owe or get refunded.

Because Louisiana's rate is low and flat, Louisiana-heavy carriers who fuel out of state usually land on the refund side of the return — tax paid at high-rate pumps against only 20 cents owed per Louisiana gallon. Returns are due April 30, July 31, October 31 and January 31, with late penalties typically $50 to $100 plus interest per missed quarter, and a filing obligation even when the net is zero. Auditors ask for four consecutive quarters of receipts, per-state distance records (ELD or GPS), and the MPG calculation behind the return; mismatched receipts and miles remain the number one finding. Pull a fresh matrix each quarter from your base state or IFTA, Inc. — the Q4 matrix finalizes in early December.