Yes, you can still pay child support with 50/50 custody in New Mexico. Under NMSA 1978, § 40-4-11.1, the state uses an income-shares model, so the higher-earning parent typically pays the lower earner even with equal time. Courts apply Worksheet B (Shared Responsibility), which uses a 1.5x multiplier and a net offset.
The question "do I still pay child support with joint custody" surprises many New Mexico parents who assume equal parenting time cancels any payment. It does not. Child support 50 50 custody New Mexico cases are governed by N.M. Stat. § 40-4-11.1, which separates two distinct factors: time spent with each child and each parent's income. Equal time neutralizes only the time-based portion of the calculation. Any meaningful income difference between the two parents still produces a net support payment that flows from the higher earner to the lower earner. This guide explains exactly how Worksheet B works, when 50/50 parenting time triggers shared-responsibility treatment, and how to estimate your obligation.
Key Facts: New Mexico Divorce and Child Support
| Factor | New Mexico Rule |
|---|---|
| Filing Fee | $137 to file a Petition for Dissolution of Marriage (uniform across all 13 judicial districts) |
| Waiting Period | No statutory waiting period; uncontested divorces with children often finalize in 60-90 days |
| Residency Requirement | One spouse must reside in New Mexico for at least 6 months and hold domicile (intent to remain) under N.M. Stat. § 40-4-5 |
| Grounds | No-fault (incompatibility) plus fault grounds; most divorces filed as no-fault |
| Property Division Type | Community property — marital assets divided equally (50/50) |
| Child Support Statute | N.M. Stat. § 40-4-11.1 (income-shares model) |
| Shared Custody Threshold | 35% of overnights (approximately 128 nights/year) triggers Worksheet B |
Filing fees are as of March 2026. Verify with your local district court clerk before filing.
Do You Pay Child Support With 50/50 Custody in New Mexico?
Yes. In most New Mexico cases with 50/50 custody, the higher-earning parent pays child support to the lower-earning parent. Under N.M. Stat. § 40-4-11.1, New Mexico applies an income-shares model that combines both parents' gross incomes and divides the total obligation by income percentage. Equal parenting time alone does not eliminate this transfer.
The reason equal custody child support still applies comes down to how the income-shares model treats two separate variables. First, the model calculates a basic support obligation based on the combined monthly gross income of both parents and the number of children. Second, it allocates responsibility for that obligation by each parent's percentage share of the combined income. A parent earning 65% of the combined income owes 65% of the basic obligation regardless of how nights are split. When parenting time is exactly 50/50 but one parent earns substantially more, the time-based credits cancel each other out while the income-based shares remain unequal — producing a net payment. Only when both incomes and both overnight counts are identical would the offset net to zero.
When Does 50/50 Custody Trigger Worksheet B in New Mexico?
New Mexico uses Worksheet B (Shared Responsibility) when each parent has the children at least 35% of the year — roughly 128 overnights annually or about 10 nights per month. Below that 35% threshold, courts use Worksheet A (Basic Visitation). A true 50/50 schedule (182-183 nights each) always exceeds the threshold and triggers Worksheet B under N.M. Stat. § 40-4-11.1.
The statute defines "shared responsibility" as a custody arrangement in which each parent provides a suitable home, the children spend at least 35% of the year in each home, and the parents significantly share the duties, responsibilities, and expenses of parenting. This is the central distinction for 50/50 parenting time support. A parent with 40% of overnights qualifies for Worksheet B even though their time is not perfectly equal. A parent with 30% of overnights — falling short of the 128-night threshold — is calculated under Worksheet A, which generally produces a higher payment because it does not credit the noncustodial parent for direct expenses during their parenting time. The 35% line is therefore one of the most consequential numbers in a New Mexico custody negotiation.
How Worksheet B Calculates Shared Custody Child Support
Worksheet B calculates shared custody child support in New Mexico through a six-step offset: it multiplies the basic obligation by 1.5, splits it by income percentage, credits each parent for their share of overnights, then nets the two figures. The parent with the larger remaining obligation — almost always the higher earner — pays the difference under N.M. Stat. § 40-4-11.1.
Here is the sequence the worksheet follows. First, the court finds the basic obligation from the state Basic Child Support Schedule using the combined monthly income and number of children (Line 4). Second, it multiplies that figure by 1.5 to account for the duplicated cost of maintaining two households (Line 5). Third, each parent's dollar share is set by their income percentage (Line 6). Fourth, each parent's overnights are divided by 365 to get a time-of-care percentage (Lines 7-8). Fifth, each parent retains a portion equal to their time-of-care percentage (Line 9), and that retained amount is subtracted from their income-based share (Line 10). Finally, the smaller Line 10 figure is subtracted from the larger to produce the net transfer (Line 11). Medical, dental insurance, and work-related childcare are then added proportionally and offset separately.
Worksheet A vs. Worksheet B: Side-by-Side
| Feature | Worksheet A (Basic Visitation) | Worksheet B (Shared Responsibility) |
|---|---|---|
| When it applies | Noncustodial parent has under 35% of overnights | Each parent has at least 35% of overnights |
| Overnight threshold | Fewer than 128 nights/year | 128+ nights/year (true 50/50 = 182-183) |
| Multiplier | None (1.0x basic obligation) | 1.5x basic obligation |
| Time-of-care credit | No | Yes — each parent credited for overnights |
| $1,200 self-support reserve | Applies | Does NOT apply |
| Typical net payment | Higher | Lower (income difference drives it) |
Why the Income-Shares Model Means You May Still Pay
New Mexico's income-shares model means a higher earner pays even with shared custody because support is allocated by income percentage, not just time. If one parent earns $6,000/month and the other earns $3,000/month, their combined income is $9,000 and their shares are 67% and 33%. The 67% parent owes two-thirds of the basic obligation under N.M. Stat. § 40-4-11.1, and 50/50 time only offsets the time-based credit.
Consider a simplified illustration with one child, a combined monthly income of $9,000, and exactly 182.5 overnights each. Suppose the schedule sets the basic obligation at $1,100. Worksheet B multiplies that by 1.5 to reach $1,650. The higher earner's income-based share (67%) is about $1,105, and the lower earner's (33%) is about $545. Each parent is credited 50% time of care, so each retains half of their own share. After the Line 10 subtraction and the Line 11 offset, the higher earner pays the lower earner roughly the difference between the two adjusted figures — typically a few hundred dollars per month. The exact figure depends on the current schedule, but the principle is consistent: shared custody child support reflects the income gap, not parenting time alone.
What Counts as Income in a New Mexico Child Support Calculation
New Mexico defines income broadly for child support: gross income includes wages, salary, commissions, bonuses, self-employment net income, pensions, Social Security benefits, unemployment, workers' compensation, spousal support received, and rental income under N.M. Stat. § 40-4-11.1. Courts may also impute income to a voluntarily unemployed or underemployed parent.
Gross income for guideline purposes is intentionally comprehensive so that neither parent can shield resources from the calculation. The statute directs courts to count income from essentially every source, then subtract limited deductions such as preexisting child support obligations and alimony actually paid. For self-employed parents, the court uses gross receipts minus ordinary and necessary business expenses — though personal expenses run through a business are typically added back. When a parent is voluntarily unemployed or underemployed, New Mexico permits the court to impute income based on earning capacity. The 2024 guideline modernization directed courts to consider real labor-market data when imputing income, noting that New Mexico's average workweek is 34.1 hours, so imputing a full 40-hour week may be inappropriate for low-wage workers.
2024 Guideline Update: What Changed for Shared Custody Cases
New Mexico modernized its Basic Child Support Schedule effective January 1, 2024, under SB223 (Laws 2023, ch. 106). The update introduced a $1,200 monthly self-support reserve for low-income paying parents, refreshed the cost-of-raising-children data, and extended the schedule to combined incomes up to $30,000 per month. These changes apply to orders entered on or after January 1, 2024, under N.M. Stat. § 40-4-11.1.
The most relevant change for 50/50 parenting time support is the self-support reserve — and an important limitation. The $1,200 reserve protects low-income payers from being ordered below a subsistence floor, but it applies only to Worksheet A calculations. Shared-responsibility Worksheet B cases are expressly not subject to the self-support reserve method, because both parents already retain funds for direct expenses during their parenting time. The 2024 update also removed the fixed schedule from the statute itself, delegating the schedule to the Health Care Authority Department by rule (published in the New Mexico Administrative Code, 8.50.108 NMAC). The guideline amount remains a rebuttable presumption: a judge may deviate only by entering written findings that the guideline result would be unjust or create substantial hardship. Existing orders are not automatically affected; the new schedule applies to new petitions and modification motions.
How to Modify a 50/50 Child Support Order in New Mexico
New Mexico permits modification of a child support order when there is a material and substantial change in circumstances, generally defined as a change that would alter the guideline amount by at least 20%. Common triggers include a job loss, a significant raise, a shift in the overnight schedule, or a change in childcare or health-insurance costs under N.M. Stat. § 40-4-11.1.
To modify, the requesting parent files a motion to modify child support in the district court that issued the original order, attaching an updated Worksheet B and supporting financial documentation. Because the 2024 schedule applies to modification motions filed after January 1, 2024, a parent reopening an older order may see a recalculated amount under the modernized figures. A shift in the parenting-time split is particularly significant in shared-custody cases: dropping below the 35% threshold moves the calculation from Worksheet B to Worksheet A, which usually increases the payment, while crossing above 35% moves it the other direction. Modifications are not retroactive before the date the motion is filed, so a parent whose income drops should file promptly rather than waiting. The New Mexico Child Support Enforcement Division can also assist with administrative reviews in certain cases.
Filing for Divorce With Children in New Mexico
To file for divorce with children in New Mexico, you submit a Petition for Dissolution of Marriage (Form 4A-103, with children), a Domestic Relations Information Sheet (Form 4A-101), and the $137 filing fee to the district court in the county where either spouse resides. At least one spouse must meet the six-month residency and domicile requirement under N.M. Stat. § 40-4-5.
The residency rule has two parts that must both be satisfied: physical presence in New Mexico for at least six months immediately before filing, and domicile — the genuine intent to remain in the state indefinitely. The six months need not be continuous; temporary absences do not reset the clock. Beyond the base $137 fee, expect service-of-process costs of $25-$50, possible motion fees of $25-$50 each, and a parenting class fee of roughly $25-$50 when children are involved. Parents who cannot afford the fee may file an Application for Free Process and Affidavit of Indigency (Form 4-222); the court can waive the fee entirely for households below 200% of the federal poverty level. Filing fees and court costs are as of March 2026 — verify current amounts with your local district court clerk. Self-help forms are available through the New Mexico Courts self-representation portal.