Child support in New Mexico
New Mexico uses the income-shares model: both parents' incomes count, and each parent pays a share of the child's support. To open a case, contact the New Mexico Health Care Authority, Child Support Services Division (CSSD) at 1-800-283-4465.
Checked against official sources: Oct 25, 2026. · Free letters and checklist ↓
How much child support in New Mexico?
Support is based on both parents' gross (before-tax) monthly incomes added together. A basic child support schedule sets the support for that combined income and number of children, and each parent pays a share in proportion to income. Child care, health insurance and time-sharing are also counted on the worksheet. Since January 1, 2024 the schedule is set by state rule.
Law: 8.50.108.10 NMAC; NMSA 1978, § 40-4-11.1 (guidelines and worksheet); 8.50.108.10 NMAC (basic schedule and self-support reserve, effective Jan. 1, 2024)
We don't estimate New Mexico's amount here: its formula uses both parents' incomes and other facts, and a home-made number could mislead you. The official tool gives the real starting number:
Open a child support case in New Mexico
- Phone
- 1-800-283-4465 (Consolidated Customer Service Center)
- Apply
- Apply online
- How to open a case
Apply for full CSSD services online at YES.nm.gov, or mail or bring the Full Services Application to your local CSSD field office. CSSD can establish paternity, get a support order from the court, and collect and enforce support. If you get TANF, a case opens automatically. You can also ask the district court for support in a divorce, custody or paternity case using the Supreme Court-approved 4A forms.
- Application fee
$0. CSSD eliminated its service fees in July 2024.
Source: CSSD brochure, 'Are There Fees?'
- Yearly fee
No fee is charged to parents: CSSD says it eliminated service fees in July 2024, and payment-processing-only cases are not charged an annual processing fee.
Source: CSSD brochure; Full Services Application, Rev. 07/2024
- Forms
- Paternity (legal fatherhood)
If the father agrees, the parents can sign an Acknowledgment of Paternity. If he disagrees, the court can order a DNA test and the local CSSD office arranges the testing; parents can also agree to DNA testing at a CSSD office. In court you can file a paternity case.
New Mexico child support by topic
How support is calculated in New Mexico
The model, the percentages or the official calculator, and low-income rules.
Change child support in New Mexico
When you can ask, how to ask, and a review letter.
Collect unpaid support in New Mexico
Collection tools, interest and license rules, and a letter.
When support ends in New Mexico
The end age, high school and disability rules.
How child support is figured in New Mexico
- Model
- Income shares
- How it works
Support is based on both parents' gross (before-tax) monthly incomes added together. A basic child support schedule sets the support for that combined income and number of children, and each parent pays a share in proportion to income. Child care, health insurance and time-sharing are also counted on the worksheet. Since January 1, 2024 the schedule is set by state rule.
Law: 8.50.108.10 NMAC
- Low income
Since January 1, 2024 the schedule includes a self-support reserve of $1,200 a month for the paying parent. If the paying parent's income and number of children fall in the shaded area of the schedule, only that parent's income is used, and child care and medical add-ons are not added.
Law: 8.50.108.7 and 8.50.108.10 NMAC
- Official calculator
- Official New Mexico child support calculator
- Health insurance and medical costs
State and federal law require medical support in every order. It can be private insurance (often through an employer), public coverage such as Medicaid, Indian Health Service or military (DEERS) coverage, cash medical support, or a split of uncovered medical costs.
Law: NMSA 1978, § 40-4C-4; CSSD Full Services Application
Law: NMSA 1978, § 40-4-11.1 (guidelines and worksheet); 8.50.108.10 NMAC (basic schedule and self-support reserve, effective Jan. 1, 2024)
Change a child support order in New Mexico
- When a change is allowed
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 to ask
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
Law: NMSA 1978, § 40-4-11.4
Can I ask for a change? Check your situation
Collect unpaid child support in New Mexico
Arrears means support that is past due. The child support agency can use these tools to collect it:
- Collection tools
- Wage withholding
- Federal and state tax refund intercept
- Driver's license suspension
- Bank account seizure
- Liens
- Credit bureau reporting
- Civil contempt: motions for order to show cause and bench warrants
- Contempt of court
CSSD attorneys can ask the court for an order to show cause or a bench warrant. You can also file your own Motion to Enforce Order in district court.
Source: form 4A-209
- Interest on unpaid support
Delinquent child support accrues interest at 4% a year from the date it is late until paid, and a consolidated judgment for past-due support also accrues 4%. Payments go first to current support, then past-due support, then interest. A 2026 bill to raise the rate to 6.5% did not pass.
Law: NMSA 1978, § 40-4-7.3; HB 266
Law: CSSD Full Services Application and brochure
When child support ends in New Mexico
- Support ends
18; if the child turns 18 while still in high school, support continues until the month the child graduates or turns 19, whichever comes first
- Exceptions
Support can continue past the usual age for a severely disabled child; courts decide case by case.
Source: OCSS IRG, New Mexico profile
Law: NMSA 1978, § 40-4-7(B); court form 4A-303
When does support end? Check your situation
Free help in New Mexico
Official self-help
Free letters and checklist
Ask the agency to review (change) your order
A letter to the child support agency asking for a review and adjustment.
Ask the agency to collect unpaid support
A letter asking the agency to enforce the order and collect what is past due.
Checklist: what to bring to open a case
IDs, birth certificates, the other parent's details and your papers, with New Mexico's agency contact.
Good to know in New Mexico
- New Mexico's child support agency stopped charging any service fees in July 2024 (CSSD brochure).
- Unpaid child support in New Mexico carries 4% interest a year (NMSA 1978, § 40-4-7.3).
- New Mexico uses gross (before-tax) income to figure support (CSSD brochure).
Changes in 2024–2026
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).
Federal rules in every state
- Applying. If you don't get TANF, Medicaid or foster care help, a state may charge an application fee of up to $25 to open a child support case. Law: 42 U.S.C. 654(6)(B)(i)
- Yearly fee. If you never got TANF and the agency collected at least $550 for you in a year, the state charges a $35 yearly fee. It can come out of your support, but never out of the first $550. Law: 42 U.S.C. 654(6)(B)(ii)
- Review every 3 years. If your case is with the child support agency, either parent can ask it to review the order every 3 years and adjust it to the guidelines. Law: 42 U.S.C. 666(a)(10)(A); 45 CFR 303.8
- Past-due support. Each unpaid payment becomes a judgment on the day it is due. It can't be lowered later, except back to the date the other parent got notice of a request to change the order. Law: 42 U.S.C. 666(a)(9)
- Tax refunds. The federal government can take a federal tax refund to pay past-due child support. Law: 42 U.S.C. 664
- Passports. A parent who owes more than $2,500 in past-due support can be refused a passport. Law: 42 U.S.C. 652(k)
- Pay withholding limit. For support, up to 50% of take-home pay can be withheld if the parent supports another spouse or child, or 60% if not. It is 55% or 65% when support is more than 12 weeks behind. Law: 15 U.S.C. 1673(b)
- How long support lasts. How long support lasts follows the law of the state that made the order, even if you move. Law: 28 U.S.C. 1738B(h)(2)
Questions about child support in New Mexico
How is child support calculated in New Mexico?
Support is based on both parents' gross (before-tax) monthly incomes added together. A basic child support schedule sets the support for that combined income and number of children, and each parent pays a share in proportion to income. Child care, health insurance and time-sharing are also counted on the worksheet. Since January 1, 2024 the schedule is set by state rule.
Is there an official child support calculator for New Mexico?
What if the paying parent has a low income in New Mexico?
Since January 1, 2024 the schedule includes a self-support reserve of $1,200 a month for the paying parent. If the paying parent's income and number of children fall in the shaded area of the schedule, only that parent's income is used, and child care and medical add-ons are not added.
How do I apply for child support in New Mexico?
Apply for full CSSD services online at YES.nm.gov, or mail or bring the Full Services Application to your local CSSD field office. CSSD can establish paternity, get a support order from the court, and collect and enforce support. If you get TANF, a case opens automatically. You can also ask the district court for support in a divorce, custody or paternity case using the Supreme Court-approved 4A forms.
Does it cost money to open a child support case in New Mexico?
$0. CSSD eliminated its service fees in July 2024.
Is there a yearly fee for child support services in New Mexico?
No fee is charged to parents: CSSD says it eliminated service fees in July 2024, and payment-processing-only cases are not charged an annual processing fee.
When can child support be changed 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.
What happens if child support is not paid in New Mexico?
Arrears means support that is past due. The child support agency can use these tools to collect it: Wage withholding; Federal and state tax refund intercept; Driver's license suspension; Bank account seizure; Liens; Credit bureau reporting; Civil contempt: motions for order to show cause and bench warrants.
Can a parent be held in contempt for not paying in New Mexico?
CSSD attorneys can ask the court for an order to show cause or a bench warrant. You can also file your own Motion to Enforce Order in district court.
Is there interest on unpaid child support in New Mexico?
Delinquent child support accrues interest at 4% a year from the date it is late until paid, and a consolidated judgment for past-due support also accrues 4%. Payments go first to current support, then past-due support, then interest. A 2026 bill to raise the rate to 6.5% did not pass.
When does child support end in New Mexico?
18; if the child turns 18 while still in high school, support continues until the month the child graduates or turns 19, whichever comes first
Does child support continue while my child finishes high school in New Mexico?
18; if the child turns 18 while still in high school, support continues until the month the child graduates or turns 19, whichever comes first
Can child support continue past the usual age in New Mexico?
Support can continue past the usual age for a severely disabled child; courts decide case by case.
How is paternity established in New Mexico?
If the father agrees, the parents can sign an Acknowledgment of Paternity. If he disagrees, the court can order a DNA test and the local CSSD office arranges the testing; parents can also agree to DNA testing at a CSSD office. In court you can file a paternity case.
Who pays for the child's health insurance in New Mexico?
State and federal law require medical support in every order. It can be private insurance (often through an employer), public coverage such as Medicaid, Indian Health Service or military (DEERS) coverage, cash medical support, or a split of uncovered medical costs.
More help on our sister sites
Sources
- NM HCA Child Support Overview
- NM HCA Applications for Child Support Services
- CSSD Application for Full Services (Rev. 07/2024)
- CSSD Brochure (10/18/24)
- NM Courts Self-Representation: Child Support & Custody
- NM Court form 4A-303 Child support obligation and order
- NM Legislature 2026 HB 266 (text showing current § 40-4-7.3)
- NM Legislature HB 266 (2026) status
- OCSS Intergovernmental Reference Guide - New Mexico profile
- HCA: State announces modernized child support guidelines for 2024
- 8.50.108 NMAC (State Records Center and Archives)
Last checked: Oct 25, 2026.
- State plan requirements: application fee, annual fee, safeguards, 42 U.S.C. 654
- Required state laws: arrears as judgments, review every 3 years, UIFSA, 42 U.S.C. 666
- Federal tax refund offset, 42 U.S.C. 664
- Passport denial for child support arrears, 42 U.S.C. 652(k)
- Garnishment limits for support orders, 15 U.S.C. 1673(b)
- Full faith and credit for child support orders, 28 U.S.C. 1738B
- Office of Child Support Enforcement (federal)