How is Child Support Calculated in Louisiana?

Louisiana combines both parents' gross incomes into one number, looks up the basic support amount on a state guideline schedule, and splits that amount between the parents based on each parent's share of the combined income. The schedule itself was updated effective January 1, 2025, raising guideline amounts across most income levels and extending the income table up to $50,000 a month in combined income.

Louisiana's income shares model: combine, then split

Louisiana uses an income shares model under La. R.S. 9:315 et seq. The idea behind income shares is that a child should generally receive close to the same proportion of parental income they would have received if both parents lived in the same household. To get there, courts add both parents' adjusted gross monthly incomes together, then figure out what percentage of that combined total each parent contributes.

That combined-income approach means both parents' earnings are part of the calculation from the first step, and both parents generally share responsibility for the basic obligation in proportion to what they earn — not just the parent who has less physical custody time.

The basic steps: schedule, split, add-ons

The calculation follows a consistent sequence built into Worksheet A under La. R.S. 9:315.8, the standard worksheet used for sole and joint custody arrangements that aren't shared roughly equally.

Step	What happens
1. Determine gross income	Each parent's gross monthly income is established, with adjustments allowed for existing support obligations to other children
2. Combine incomes	Both parents' adjusted gross incomes are added together to get the combined monthly figure
3. Find each parent's share	Each parent's income is divided by the combined total to get a percentage contribution
4. Look up the basic obligation	The combined income and number of children are matched against the Schedule of Basic Child Support Obligations in La. R.S. 9:315.19
5. Split the basic obligation	Each parent's percentage share (step 3) is applied to the basic obligation (step 4)
6. Add child care, insurance, and medical costs	The paying parent's share of net child care costs, health insurance premiums, and extraordinary medical expenses is added to the basic amount

This sequence produces the standard order for parents who don't share custody on an approximately equal basis. A different worksheet — Worksheet B, covered further down — applies when custody time is close to a 50/50 split.

What counts as income in Louisiana

Louisiana's guidelines define gross income broadly — most money coming in before taxes generally counts toward the calculation.

Income type	Generally included?
Wages, salaries, commissions, bonuses, tips	Yes
Self-employment income	Yes — gross receipts minus ordinary business expenses
Pension, retirement, and Social Security income	Yes
Disability and workers' compensation payments	Yes
Spousal support received from a prior relationship	Yes
Means-tested public assistance (SNAP, SSI, TANF)	Generally excluded

The 2025 update: a higher schedule, a wider table

Louisiana's guideline schedule was most recently revised by Act 2024, No. 86, effective January 1, 2025. The update raised the support amounts built into the Schedule of Basic Child Support Obligations (La. R.S. 9:315.19) and extended the table to cover combined monthly gross incomes from $1,050 up to $50,000. Below $1,050 in combined income or above $50,000, the schedule doesn't provide a direct figure, and courts have discretion to set an amount based on the case's specific circumstances.

The schedule also builds in a self-sufficiency reserve for lower-income parents — support amounts start low and rise gradually at the bottom of the income range. At $1,050 in combined monthly income, for example, the basic obligation for one child is about $43 a month; it climbs to roughly $1,210 a month by the time combined income reaches $8,000.

Worked example — the basic calculation

Shared custody: when Worksheet B applies

Louisiana switches from the standard Worksheet A to the shared custody Worksheet B under La. R.S. 9:315.9 when each parent has physical custody of the child for an approximately equal amount of time. Worksheet B first multiplies the basic obligation by 1.5 to account for the fact that each parent is maintaining a household capable of housing the child, then divides that larger figure between the parents in proportion to income. Each parent's resulting theoretical obligation is then cross-multiplied by the percentage of time the child spends with the other parent, and the parent left with the larger adjusted amount generally pays the other the difference.

Worked example — shared custody adjustment

Health insurance, medical expenses, and child care add-ons

The basic obligation from the schedule covers everyday costs like housing, food, and clothing. On top of that, Worksheet A adds net child care costs (work or job-search related child care, minus any federal tax credit the paying parent receives for it), the portion of a health insurance premium covering the child, and extraordinary medical expenses — costs beyond ordinary co-pays, such as orthodontia, therapy, or other significant uninsured medical needs. These add-ons are generally divided between the parents in the same proportion as their income share, and whichever parent pays the health insurance premium typically receives credit for the child's portion of that cost.

For a broader look at how property and spousal support are handled alongside child support, see the Louisiana divorce finances overview. We also have a companion guide on how alimony is calculated in Louisiana, including the one-third-of-net-income cap on final periodic support.

When can Louisiana child support be modified?

Under La. R.S. 9:311, either parent can ask a court to modify an existing order by showing a material change in circumstances that is substantial and continuing since the last award. Louisiana law creates a rebuttable presumption that a material change exists when applying the current guidelines would change the support amount by 25% or more compared to the existing order — though a court retains discretion to modify support for other substantial and continuing changes even when that 25% threshold isn't met. Informally reducing or skipping payments without a modified court order is not a safe substitute for going back to court, since the original order generally stays enforceable until it's formally changed. For more on how modification typically works, see our general guide on child support modification.

Common questions about Louisiana child support

How is child support calculated in Louisiana? Louisiana combines both parents' adjusted gross monthly incomes, looks up the combined obligation on the guideline schedule in La. R.S. 9:315.19, splits it based on each parent's income share, and then adds child care, health insurance, and extraordinary medical costs divided the same way. For a broader explanation of income shares versus other state models, see our general guide on how child support is calculated.

What is Worksheet B and how does shared custody change the calculation? Worksheet B applies when each parent has the child for an approximately equal amount of time. It multiplies the basic obligation by 1.5, splits that by income share, then cross-multiplies each parent's theoretical share by the time the child spends with the other parent — the parent with the larger adjusted amount generally pays the difference.

What counts as income for Louisiana child support? Wages, salaries, bonuses, self-employment income, pensions, disability payments, and most other regular income generally count. Means-tested public assistance is generally excluded, and a court may impute income to a parent who is voluntarily unemployed or underemployed.

Can Louisiana child support be modified? Yes, when there's been a material change in circumstances that's substantial and continuing — a 25% or greater change under the guidelines creates a rebuttable presumption that modification is warranted, though courts have discretion to modify support for other qualifying changes too.