Louisiana state income tax is a flat 3% on taxable income for tax year 2025 and later, with annual returns due May 15 of the following year. Residents file Form IT-540; part-year residents and non-residents with Louisiana-source income file Form IT-540B. Both start from the federal adjusted gross income on your federal return, so you need the federal version done first.
The Flat 3% Rate
Every dollar of Louisiana taxable income is taxed at 3%, regardless of how much you earn or how you file.1Louisiana Department of Revenue. What Are the Individual Income Tax Rates and Brackets? The old three-tier system that ran from 1.85% to 4.25% was repealed by Act 11 of the 2024 Third Extraordinary Legislative Session and no longer applies to tax years beginning on or after January 1, 2025.
The calculation is straightforward once you have your Louisiana taxable income: multiply it by 0.03. The work is in getting to that figure through the standard deduction, exclusions, and credits described below.
Who Has to File
If you are required to file a federal individual income tax return and you are a Louisiana resident, you must also file a Louisiana return reporting all of your income.2Louisiana Department of Revenue. Individual Income Tax You also need to file if Louisiana tax was withheld from your pay and you want it refunded, even when your income was too low to require a federal return.
Under Louisiana Revised Statute 47:31, you count as a resident if you are domiciled in the state, maintain a permanent home there, or spend more than six months of the tax year within its borders.3Justia. Louisiana Code RS 47-31 – Individuals, Corporations, and Trusts Subject to Tax Meeting any one of the three is enough.
Part-year residents owe tax on income earned while they lived in Louisiana. Non-residents who earned money from Louisiana sources, such as rental property, a business operating in the state, or wages for work performed there, also have a filing obligation. Both groups use Form IT-540B, which apportions income between Louisiana and other states.2Louisiana Department of Revenue. Individual Income Tax Have your W-2s, 1099s, and Social Security numbers for everyone on the return ready, along with the completed federal 1040.
Standard Deduction
Louisiana’s standard deduction for 2025 and later tax years is:4Louisiana Department of Revenue. Are There Any Changes to the Combined Personal Exemption Standard Deduction?
- $12,500 for single filers and married individuals filing separately
- $25,000 for married couples filing jointly, qualifying surviving spouses, and heads of household
The separate personal exemptions that previously applied to dependents, blind individuals, and taxpayers over 65 were repealed as part of the 2024 reform, and the larger standard deduction absorbs them.5Louisiana Department of Revenue. Revenue Information Bulletin No. 25-012 Federal itemized deductions generally do not carry over to Louisiana beyond the standard deduction, though if you itemized federally you may claim an additional reduction for the portion of medical and dental expenses that exceeds a statutory threshold.6Louisiana Department of Revenue. Individual Income Tax Return Instructions
Income Louisiana Doesn’t Tax
Several categories of income are excluded from Louisiana taxable income, which reduces the base the 3% rate applies to.
Social Security and Retirement Income
Louisiana does not tax Social Security benefits. The exemption covers all benefits paid under Chapter 7 of Title 42 of the U.S. Code, including retirement, disability, and survivor payments, and the same statute exempts income from U.S. government retirement systems and Railroad Retirement Act benefits.7Justia. Louisiana Code RS 47-44.2 – Federal Social Security Benefits
Benefits paid by Louisiana’s own public retirement systems, such as the Teachers’ Retirement System and the Louisiana State Employees’ Retirement System, are also exempt.8Louisiana State Legislature. Louisiana Revised Statutes RS 11-1331 – Exemption From State Income Taxes On top of those categorical exclusions, anyone 65 or older can exclude up to $12,000 per year of other annual retirement income. On a joint return where both spouses are 65 or older, each spouse can claim the $12,000 exclusion.9Louisiana Department of Revenue. Is There a List of Retirement System Benefits That May Be Excluded From Louisiana Income Tax?
Military Pay
Louisiana residents on active duty who are stationed outside the state for 120 or more consecutive days can exclude up to $50,000 of military compensation (increased from $30,000 beginning in 2022).10Louisiana State Legislature. Louisiana Revised Statutes RS 47-293 Pay earned during periods of in-state assignment doesn’t qualify.
School Expenses for Dependents
You can deduct qualified education expenses for dependents in elementary or secondary school. For a child enrolled in a nonpublic school, the deduction is up to $6,000 per dependent in actual costs paid. For a home-schooled child or one in public school, the deduction equals 50% of costs paid, also capped at $6,000 per dependent.11Louisiana Department of Revenue. School Expense Deduction Report it on Schedule E of Form IT-540, attach the School Expense Deduction Worksheet, and keep your receipts; the Department can ask for proof.
Federal Tax Deduction (No Longer Available)
Louisiana once let residents deduct federal income taxes paid from state taxable income. That deduction expired on December 31, 2021, and was not renewed, so older guides that mention it are out of date.12Louisiana Department of Revenue. Does the Constitutional Amendment Eliminate the Federal Income Tax Deduction?
Deadline, Extensions, and Penalties
Louisiana’s return is due May 15 of the year following the tax year, about a month after the federal deadline.13Louisiana Department of Revenue. Filing Dates You can request an extension if you cannot file on time, but an extension only gives you more time to file the paperwork. Any tax owed is still due by May 15, and interest starts accruing the next day.
For 2026, interest on unpaid Louisiana taxes runs at an annual rate of 10.50%, or 0.875% per month.14Louisiana Department of Revenue. Interest Rate Schedule The rate adjusts annually under a statutory formula, capped at 1.25% per month.15Justia. Louisiana Code RS 47-1601 – Interest on Unpaid Taxes
A separate late-filing penalty applies when you file after the deadline: 5% of the tax due for the first 30 days of delinquency, plus 5% for each additional 30-day period or fraction of one, up to a maximum of 25%.16Louisiana State Legislature. Louisiana Code RS 47-1602 – Penalty for Failure to Make Timely Return Interest and penalty stack, so paying what you expect to owe by May 15 matters even when the return itself isn’t finished.
Estimated Payments if You Don’t Have Withholding
If you expect to owe more than $1,000 in Louisiana income tax after credits and withholding ($2,000 for joint filers), you have to make quarterly estimated payments.17Louisiana Department of Revenue. Declaration of Estimated Income Taxes This mainly reaches self-employed individuals, freelancers, landlords, and anyone with significant income the state isn’t already withholding on.
Calendar-year taxpayers can pay in full with their declaration or split the amount into four equal installments due April 15, June 15, September 15, and January 15 of the following year.17Louisiana Department of Revenue. Declaration of Estimated Income Taxes Miss a deadline or underpay, and Louisiana charges a 12% annual penalty on the underpayment for the period it remains unpaid. You can avoid the penalty if your total estimated payments equal or exceed the tax you owed on last year’s return, assuming that return covered a full 12 months.
How to File
The simplest route is electronic filing through Louisiana’s free LaTAP portal (Louisiana Taxpayer Access Point), which handles individual income tax returns for tax year 2022 and later at no charge.18Louisiana Department of Revenue. Individual Income Online Tax Filing The same account lets you make payments, check refund status, and manage other state tax obligations. Most commercial tax preparation software can also e-file your Louisiana return alongside the federal one.
If you file on paper, mail your completed IT-540 or IT-540B to the Louisiana Department of Revenue in Baton Rouge. The mailing address differs depending on whether you owe tax or expect a refund, and the correct address is printed in the form instructions. Downloadable forms and instruction booklets are on the Department’s website.19Louisiana Department of Revenue. Tax Forms for Individuals After filing, you can track your refund through the Department’s online tools.