New Mexico Child Support Calculator

How is Child Support Calculated in New Mexico?

Governed by NMSA § 40-4-11.1, New Mexico calculates child support by first combining your and the other parent's gross incomes. This combined income is used to find a basic support amount on a state schedule, which is then divided between you based on your percentage share of the income. Costs for health insurance and childcare are added on top of this amount.

Understanding Shared Custody & Overnights

Under NMSA § 40-4-11.1, New Mexico uses a different formula for shared parenting arrangements, which significantly impacts the final child support amount. This special calculation, known as Worksheet B, is triggered when a parent has the children for at least 128 overnights per year (35% of the time). The formula increases the base obligation by 50% to account for duplicated costs and then credits each parent for the time they spend with the children.

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✓ Verified for 2026 Guidelines • Reviewed October 2026 by Harmoney

New Mexico Child Support Guidelines at a Glance

Guideline Model Income Shares Model
Governing Legal Authority NMSA § 40-4-11.1
Shared Custody Threshold 128 Overnights (35% time)
Age Support Ends Age 18 (or 19 if unmarried and in High School)
Modification Standard Substantial & Material Change in Circumstances (>20% Change)

New Mexico Child Support FAQs


At what age does child support end in NM?

Child support in New Mexico ends when a child turns 18, or up to age 19 if the child is unmarried and still attending high school full-time. Per NMSA § 40-4-7(B)(3), the obligation terminates upon the child's emancipation by law, which includes reaching the age of majority or graduating from high school, whichever occurs last.

How is child support calculated if one parent is unemployed in NM?

If a parent is voluntarily unemployed or underemployed, New Mexico courts will impute a potential income to them for child support calculation purposes. Based on NMSA § 40-4-11.1(C)(2), this imputed amount is determined by the parent's employment history, skills, education, and local job market opportunities.

How do I modify a child support order in NM?

You can modify a child support order in New Mexico by proving a 'material and substantial change in circumstances' has occurred since the last order was entered. While NMSA § 40-4-11.4 establishes this legal standard, a change that results in a 20% or greater difference in the calculated support amount is often considered sufficient to warrant a review.

Does NM child support cover college expenses?

No, New Mexico law does not require parents to pay for college expenses as part of child support after a child reaches the age of majority. Support for post-secondary education can only be enforced if the parents have voluntarily agreed to it in a signed and court-approved marital settlement agreement.

How does NM handle health insurance and childcare costs?

Health insurance premiums and reasonable work-related childcare costs are added to the basic child support obligation and divided between the parents in proportion to their respective incomes. As outlined in NMSA § 40-4-11.1, these mandatory add-on expenses are separate from the base support amount determined from the guideline tables.