Child Support Calculations in New Mexico

New Mexico uses the Income Shares model under NMSA § 40-4-11.1, combining both parents' incomes and allocating support proportionally. Whether you're navigating an uncontested or contested divorce, understanding the 2024 guideline changes—including the new Self-Support Reserve and updated worksheets—is essential.

The Income Shares Model

New Mexico calculates child support using both parents' combined gross income to estimate child-rearing costs, then allocates each parent's share proportionally. Access the official 2024 Child Support Worksheet from the New Mexico Courts.

• Step 1: Calculate each parent's monthly gross income
• Step 2: Compute each parent's percentage share of combined income
• Step 3: Look up the Basic Support Obligation in the schedule (round combined income to nearest $50)
• Step 4: Add health insurance and work-related childcare costs
• Step 5: Allocate total support by income shares
• Step 6: Credit direct payments to determine net transfer

Worksheet A vs. Worksheet B

New Mexico uses two different worksheets depending on custody arrangements:

• Worksheet A (Basic Visitation): Used when the noncustodial parent has less than 35% of overnights
• Worksheet B (Shared Responsibility): Used when each parent has at least 35% of overnights AND substantially shares duties and expenses

Important: Shared responsibility requires both the 35% time threshold AND significantly shared parenting duties. Equal overnights alone may not qualify if expenses aren't truly shared.

Self-Support Reserve (2024 Update)

Effective January 1, 2024, New Mexico introduced a Self-Support Reserve (SSR) of $1,200/month to protect very low-income payers:

• SSR threshold: $1,200/month (slightly above federal poverty level for one person)
• SSR application: When payer's income falls in the shaded SSR area of the schedule, use only payer's income (not combined)
• No add-ons in SSR cases: Do not add childcare, insurance, or other costs when SSR applies
• Worksheet A only: SSR does not apply to shared responsibility (Worksheet B) cases

Minimum orders in SSR band: $60 (1 child), $75 (2), $90 (3), $105 (4), $120 (5), $135 (6). Add $15 per additional child.

What Counts as Gross Income

New Mexico broadly defines gross income to include:

• Employment income: Wages, salaries, tips, commissions, bonuses, severance
• Self-employment: Gross receipts minus ordinary and necessary expenses
• Investment income: Dividends, interest, capital gains, trust income
• Benefits: Pensions, Social Security, workers' compensation, unemployment, disability
• In-kind benefits: Employer-provided items reducing personal living expenses
• Alimony received: Counts as income

Excluded from gross income: Means-tested public assistance (TANF/SSI), child's own earnings, child support received for other children, alimony paid under court order, and court-ordered support for prior children.

High-Income Cases: Above $40,000/Month

The schedule runs up to $40,000/month combined income. Above this, New Mexico uses a linear extension formula:

• Base amounts at $40,000: $2,956 (1 child), $4,341 (2), $5,058 (3), $5,650 (4), $6,214 (5), $6,755 (6)
• Extension formula: Add a percentage of income over $40,000
• Percentages: 5.4% (1 child), 7.7% (2), 8.7% (3), 9.7% (4), 10.7% (5), 11.6% (6)

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Add-Ons and Deviations

Beyond basic support, New Mexico allocates additional costs by income share:

• Health/dental insurance: Child's premium share allocated proportionally
• Work-related childcare: Net reasonable costs for employment or job search
• Extraordinary medical: Uninsured medical/dental/counseling over $100 per child per year
• Extraordinary education: Special educational expenses when ordered
• Long-distance costs: Travel and communication for parenting time

40% hardship presumption: If a single support obligation exceeds 40% of the obligor's gross income, there is a presumption of substantial hardship justifying deviation.

Duration of Support

New Mexico child support typically continues until:

• Age 18: Standard termination at majority
• High school extension: May continue until graduation if child is still in high school, but not past age 19
• Written agreement: Courts may enforce parental agreements to extend support (e.g., college)
• Disabled adult children: Support may continue when disability predates majority and child cannot be self-supporting

Modification Standards

Either parent may request modification based on material and substantial change:

• 20% threshold: A statutory presumption of material change exists when recalculation under current guidelines differs by more than 20% from the existing order
• One-year requirement: The 20% presumption applies only if petition is filed more than one year after the prior order
• Annual document exchange: Orders must include a clause requiring annual exchange of financial information upon written request
• 36-month IV-D review: Title IV-D cases may request review every 36 months
• Retroactivity: Modifications generally effective only from filing date forward

Enforcement and Arrears

New Mexico uses multiple enforcement tools through the Child Support Services Division (CSSD):

• Immediate income withholding: Default in new/modified orders without waiting for arrears
• License suspension: After 30+ days delinquent, professional, driver, and recreational licenses may be suspended
• Tax refund intercept: State and federal refunds may be seized
• Passport denial: Federal denial at threshold arrears amount
• Liens and levies: Against property and bank accounts
• Credit bureau reporting: Delinquencies reported
• Lottery prize intercept: New Mexico intercepts lottery winnings

Interest on Arrears

New Mexico charges interest on delinquent child support:

• Interest rate: 4% per year (simple, not compounding)
• When it accrues: From the date support becomes delinquent
• Payment order: Current support first, then delinquent support, then arrears judgment, then interest
• Interest forgiveness: State may forgive accrued interest in assigned cases if it increases collections

Common Calculation Mistakes

• Not rounding income: Combined income must be rounded to the nearest $50 before schedule lookup
• Adding costs in SSR cases: When SSR applies, use only payer's income and do not add childcare/insurance
• Misclassifying shared responsibility: Both 35%+ overnights AND shared expenses required—time alone isn't enough
• Ignoring 40% hardship rule: If support exceeds 40% of obligor's gross income, deviation is presumed justified
• Delaying modification: Relief is retroactive only to filing date—file promptly when circumstances change
• Using unofficial calculators: Third-party calculators may not reflect 2024 SSR and schedule changes

Key Takeaways

• Income Shares model: Both parents' incomes combined, allocated proportionally
• Self-Support Reserve: $1,200/month protects very low-income payers (2024 update)
• $40,000 combined cap: Linear extension formula applies above cap
• 35% shared threshold: Worksheet B requires both time AND shared expenses
• 40% hardship presumption: Deviation presumed if support exceeds 40% of obligor's gross
• 20% modification rule: Presumed material change if recalculation differs by 20%+ after one year
• 4% arrears interest: Simple interest from delinquency date
• Age 18 majority: With high school extension to 19

For more information about New Mexico divorce processes, see our New Mexico divorce timeline and filing checklist. For property division information, review our New Mexico marital property guide.