New Mexico Child Support Calculator

Estimate New Mexico child support for 2026 using the Income Shares guideline model under NMSA § 40-4-11.1. Enter both parents' incomes and the parenting-time split to see what you may owe or receive.

New Mexico follows the Income Shares model under NMSA § 40-4-11.1. The court combines both parents' monthly gross incomes, looks up the basic support obligation on the state's guideline schedule for that income level and number of children, then prorates the obligation between the parents according to each parent's percentage share of the combined income.

New Mexico uses a shared-care formula tied to overnights. When each parent has at least 35% of the overnights, the court uses the shared-responsibility calculation (Worksheet B) instead of the standard Worksheet A. Below that 35% threshold, the basic obligation is split by income share with no overnight credit. More overnights with the higher-earning parent generally lowers the amount that parent pays, but the exact change depends on both incomes and the guideline schedule.

The cost of the child's health insurance premium is treated as an adjustment under the New Mexico guideline. The premium paid for the children is added to the basic support obligation and then shared between the parents in proportion to their percentage of combined gross income. The parent who actually pays the premium typically receives credit for it. The on-page calculator only estimates this, so confirm the figures on the official CSED worksheet.

Work-related child care and daycare costs are an allowed adjustment in New Mexico. Reasonable child care expenses that let a parent work or look for work are added to the basic support obligation and divided between the parents according to each parent's share of the combined gross income, the same way the basic obligation is prorated. Keep receipts and records, because the court and CSED will want proof of the actual cost before including it.

The guideline amount under NMSA 40-4-11.1 is presumed correct in New Mexico, but a judge may deviate when applying it would be unjust or inappropriate in a specific case. The parent asking for a different number carries the burden of showing why, and the court must put its reasons in writing or on the record. Factors can include extraordinary expenses, a child's special needs, or other circumstances the guideline does not capture.

Frequently asked questions

How is child support calculated in New Mexico?

New Mexico uses the Income Shares model under NMSA 40-4-11.1. The court adds both parents' monthly gross incomes together, finds the basic support obligation on the state guideline schedule for that combined income and the number of children, then splits that obligation between the parents by each parent's percentage share of the combined income. Add-ons like health insurance and work-related child care are folded in and shared the same way. The New Mexico Child Support Enforcement Division (CSED) administers orders. The calculator on this page gives an estimate only, and the official worksheet or a licensed attorney controls the final number.

Is there an official New Mexico child support worksheet I have to use?

Yes. New Mexico has official guideline worksheets that are the controlling forms for setting support under NMSA 40-4-11.1. Worksheet A is used in standard custody situations, and Worksheet B is the shared-responsibility worksheet used when each parent has at least 35% of the overnights. The Child Support Enforcement Division posts these forms at its forms page (hsd.state.nm.us/CSED/forms.html). Whatever number you get from this site's calculator is just an estimate. The completed official worksheet, reviewed by the court, is what determines the legally binding obligation, so always fill out the correct worksheet for your situation.

How do shared or 50/50 parenting schedules change child support in New Mexico?

New Mexico applies a shared-care formula once each parent has at least 35% of the yearly overnights. At that point the court uses Worksheet B, the shared-responsibility calculation, instead of the standard Worksheet A. Worksheet B accounts for the fact that both parents are covering direct costs during their time, so a true 50/50 split usually produces a smaller transfer than a primary-custody arrangement. The higher earner still typically pays something to balance the income difference. Below 35% overnights, no shared-care credit applies. Because the math is sensitive to both incomes and overnight counts, treat the on-page result as an estimate and confirm it on the official worksheet.

What counts as income for New Mexico child support?

New Mexico bases support on gross income from nearly any source. Under the guideline that includes salaries, wages, self-employment earnings, bonuses, commissions, severance, royalties, dividends, interest, rental income, retirement, Social Security, workers' compensation, and unemployment benefits. Because the state combines both parents' gross monthly incomes before looking up the basic obligation, accurate income figures for both sides matter a lot. Self-employed parents should expect to document earnings net of legitimate business expenses. The agency administering these cases is the New Mexico Child Support Enforcement Division. This page's calculator estimates the result, but the official worksheet and the court decide what income is actually counted.

Can a New Mexico judge order a different amount than the guideline says?

Yes, but the guideline figure under NMSA 40-4-11.1 is presumed correct, so deviations are the exception. A judge can order a different amount when following the guideline would be unjust or inappropriate for that family, and the parent requesting the change must prove why. The court has to state its reasons in writing or on the record. Common grounds include a child's special or extraordinary needs, unusual expenses, or situations the schedule does not address. Because deviations require a specific justification, do not assume one will apply. The calculator here estimates the standard guideline number, not any deviation a court might grant.

When does child support end in New Mexico?

In New Mexico child support generally ends when the child turns 18. If the child is still attending high school at 18, support can continue until age 19. Support does not automatically stop on its own in every case, so a parent may need to address the existing order when a child reaches the cutoff, especially when more than one child is covered. Continuing support may also be ordered for a disabled adult child. The Child Support Enforcement Division can help with questions about an active order. For your specific end date, rely on your order and the official worksheet rather than this estimate.

How do I change an existing New Mexico child support order?

You can change a New Mexico order by filing a motion in district court or requesting a review through the Child Support Enforcement Division. Modification is supported when there is a 20% variance between the existing order and a fresh guideline calculation, or when there is a material change in circumstances such as a job loss, a significant income change, or a shift in the parenting schedule. Until a court enters a new order, the current amount stays in force, so do not just stop paying. Use this site's calculator to estimate whether a recalculation would cross the 20% threshold, then confirm with the official worksheet.