How to change child support in New Mexico

When a change is allowed, how to ask the agency or the court, and a free letter to ask for a review.

Checked against official sources: Oct 25, 2026.

Short answer

To modify an order means to change the amount by a new order. A change of more than 20% in the support amount under the guidelines, when at least one year has passed since the last order, creates a presumption that the order should be modified.

Agency review
Every 3 years if a parent asks (federal law)
First form
Court form 4A-321 Motion to modify order

The rule for changing support in New Mexico

A change of more than 20% in the support amount under the guidelines, when at least one year has passed since the last order, creates a presumption that the order should be modified. CSSD reviews its cases at least every three years, and a change in custody can be a reason to ask at any time. Either parent can also ask once a year in writing to exchange tax returns and income information.

Law: NMSA 1978, § 40-4-11.4

Can I ask for a change? Check your situation

New Mexico's rule: A change of more than 20% in the support amount under the guidelines, when at least one year has passed since the last order, creates a presumption that the order should be modified. CSSD reviews its cases at least every three years, and a change in custody can be a reason to ask at any time. Either parent can also ask once a year in writing to exchange tax returns and income information.

Law: NMSA 1978, § 40-4-11.4

Until a new order is made, the current amount is still owed. A change can count only from the date the other parent gets notice of your request, so ask soon.

Law: 42 U.S.C. 666(a)(9)

How to ask in New Mexico: Ask CSSD for a review if you have a CSSD case. Or file a Motion to Modify Order in the district court that issued the order.

Asking for a review in New Mexico

Ask CSSD for a review if you have a CSSD case. Or file a Motion to Modify Order in the district court that issued the order.

Source: form 4A-321

Write to the child support agency to ask for a review: Ask the agency to review (change) your order

What changed in 2024–2026 in New Mexico

January 1, 2024: a new basic child support schedule took effect, set by state rule under authority from Senate Bill 223 (2023). It added a $1,200 self-support reserve for low-income paying parents and ended $5 cash medical support orders for children on Medicaid (HCA announcement; 8.50.108 NMAC). July 2024: CSSD eliminated service fees for parents. 2026: House Bill 266, which would have raised interest on delinquent child support from 4% to 6.5%, died without passing (postponed indefinitely).

If a parent is in jail or prison

State guidelines may not treat time in jail or prison as choosing not to work, when support is set or changed.

Law: 45 CFR 302.56(c)(3)

In nearby states

Your next steps in New Mexico

  1. Find your order

    Note the date it was made or last changed and the amount.

  2. See if a change is allowed

    In New Mexico: A change of more than 20% in the support amount under the guidelines, when at least one year has passed since the last order, creates a presumption that the order should be modified.

  3. Collect papers

    Papers that show the change make the request stronger.

  4. Send your request

    Ask for a review with New Mexico Health Care Authority, Child Support Services Division (CSSD) (1-800-283-4465) · Apply online

  5. Talk to legal aid

    Ask for free help: New Mexico Courts HelpLine and New Mexico Legal Aid.

Where to get free help in New Mexico

Questions about changing support in New Mexico

How often can I ask for a change in New Mexico?

A change of more than 20% in the support amount under the guidelines, when at least one year has passed since the last order, creates a presumption that the order should be modified. CSSD reviews its cases at least every three years, and a change in custody can be a reason to ask at any time. Either parent can also ask once a year in writing to exchange tax returns and income information.

How do I ask to change child support in New Mexico?

Ask CSSD for a review if you have a CSSD case. Or file a Motion to Modify Order in the district court that issued the order.

Keep reading about New Mexico

Sources

Sources

Last checked: Oct 25, 2026.

Federal sources