Vermont Overnight Custody and Child Support: The 25% Threshold Explained

In Vermont, the number of overnights your child spends with each parent directly determines which child support formula applies. A difference of just a few nights per year can shift the calculation from one tier to another — and the financial impact can be substantial.

The Three Overnight Tiers

Vermont child support guidelines under 15 V.S.A. § 657 establish three distinct calculation tiers:

Tier 1: Under 25% of Overnights (Fewer Than 91 Nights)

When the non-primary parent has the child for fewer than 91 overnights per year, the case is treated as sole custody for child support purposes. The primary parent receives the full, unadjusted guideline support amount. The non-primary parent receives no credit for their parenting time.

Tier 2: 25% to 29% of Overnights (91 to 109 Nights)

When the non-primary parent reaches 91 overnights but stays below 110, support is calculated using the Partial Shared Costs Table. This sliding scale reduces the non-primary parent's payment as overnights increase. It's designed to reflect the increasing costs of maintaining a child-ready second household while minimizing fights over individual nights.

Tier 3: 30% or More of Overnights (110+ Nights)

At 110 overnights, the case shifts to the shared custody formula. Two major things change:

1. The total basic child support obligation is multiplied by 1.5 — a 50% increase to account for the reality that two full-time households cost more than one
2. This inflated total is split proportionally based on each parent's income and their share of overnights
3. The parent with the larger calculated obligation pays the net difference to the other parent

The 1.5x multiplier means the total support pool is larger under shared custody, but each parent's actual payment depends on income and time distribution.

How the Income Shares Model Works

Vermont uses the Income Shares Model, which calculates child support based on what the child would receive if the family were intact. The basic steps:

1. Calculate each parent's monthly gross income from all sources (wages, bonuses, self-employment, pensions, interest, disability benefits). Means-tested benefits like SSI or Reach Up are excluded.
2. Deduct self-employment taxes, spousal maintenance, and pre-existing child support orders to get adjusted gross income.
3. Convert to after-tax income using the state's Tax Conversion Table.
4. Combine both parents' available incomes, then locate the basic child support obligation on the Intact Family Expenditures Table based on combined income and number of children.
5. Split the obligation proportionally based on each parent's income share.
6. Add work-related childcare costs and the child's health insurance premiums, also split proportionally.

If a parent is voluntarily unemployed or underemployed, the court can impute income based on their earning capacity — unless they're physically incapacitated, enrolled in vocational training, or caring for an infant.

The Self-Support Reserve

The paying parent is entitled to keep enough income to cover basic living expenses — the self-support reserve based on federal poverty guidelines, updated annually. The final monthly child support payment is the lesser of:

• The calculated support obligation, OR
• The paying parent's income available above the self-support reserve

This prevents support orders from pushing the paying parent below the poverty line.

Additional Costs Beyond Basic Support

On top of the base calculation, parents split:

• Health insurance premiums for the child — the court orders which parent carries coverage
• Unreimbursed medical expenses — the primary parent covers the first $200 per child per year; amounts above that are split by income percentage
• Work-related childcare — proportionally split

Strategic Considerations

The overnight thresholds create natural negotiation pressure points. A few things to keep in mind:

• Counting overnights accurately matters. Include regular schedule overnights, holiday overnights, and summer vacation nights.
• Courts look unfavorably on parents who appear to be schedule-shopping to hit a threshold purely for financial reasons rather than the child's welfare.
• The 25% threshold (91 nights) is roughly one overnight every four days — a Wednesday overnight plus every-other-weekend schedule gets you there.

The Vermont Child Custody & Parenting Plan Guide includes a child support worksheet and overnight calculator that lets you model different schedules against the three tiers before you negotiate.

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