Boise Child Support Attorney | Idaho Child Support Guidelines

A Boise child support attorney helps Idaho parents calculate, modify, and enforce support under the Idaho Child Support Guidelines, which are Rule 120 of the Idaho Rules of Family Law Procedure. The Law Office of Michael J. Holmes represents both paying and receiving parents in Ada County, Canyon County, and across the Treasure Valley.

How Idaho Calculates Child Support

Idaho uses an income shares model. Both parents’ Guidelines Income is combined, a basic support obligation is drawn from the Rule 120 schedule, and each parent is responsible for a share in proportion to their income. The schedule is tiered: rates step down across successive brackets rather than applying one flat percentage.

Idaho Code § 32-706(5) creates a rebuttable presumption that the guideline amount is correct. To depart from it, a court must make a written or on-the-record finding that applying the Guidelines would be unjust or inappropriate — and Rule 120(b)(3) additionally requires the court to state the dollar amount the Guidelines would have produced before explaining the departure.

Above $440,000 of combined Guidelines Income the schedule is not a ceiling. Support on the first $440,000 is calculated normally, and additional support is discretionary using factors that include the child’s financial resources and needs, the standard of living during the marriage, any disability or special educational need, and any special talent and the cost of developing it.

What Counts as Income

Guidelines Income is broad: salaries, wages, commissions, bonuses, dividends, interest, trust income, pensions and annuities, Social Security, workers’ compensation, unemployment and disability insurance, spousal maintenance received, veterans’ benefits, and education grants and scholarships.

Several things are not counted:

Child support you receive — it is assumed to be spent on the child and is not your income.
Benefits paid because of the child’s own disability — not income to either parent.
A new spouse’s community property interest, absent compelling reasons.
Overtime and second-job income — but only if all five conditions in Rule 120(e)(1)(B) are met, including that the work is genuinely voluntary, that the parent did not change jobs to affect the calculation, and that they are paid full time for at least 48 weeks a year. Self-employed people working more than 40 hours a week generally cannot claim this.

For the self-employed, income is gross receipts minus ordinary and necessary business expenses. The court may disallow expenses it does not consider ordinary and necessary, and the resulting figure may differ from what your tax return shows. Significant employment benefits that reduce living expenses — a company vehicle, housing, a fuel card — are added back in.

Imputed income

If a parent is voluntarily unemployed or underemployed, support is based on potential income determined from work history, qualifications, and job opportunities in the community. Three limits matter:

Income is not imputed to a parent who is physically or mentally incapacitated.
Incarceration may not be treated as voluntary unemployment when establishing or modifying support.
A parent is generally not underemployed if working full time in the same or a similar occupation held for more than six months before filing, or while caring for a child under six months of age.

Shared and Split Custody

The threshold is more than 25% of the overnights in a calendar year with each parent, and overnights are the measure. Alternating weekends works out to roughly 52 overnights, or about 14% — below the line. Twenty-five percent is about 91 overnights.

At or below 25%, no adjustment is made. Above it, Rule 120(i)(4) applies a shared-custody formula that recognises the overall increase in costs when a child maintains two homes: the basic obligation is multiplied by 1.5, apportioned by each parent’s share of income, multiplied by the share of time the child spends with the other parent, and the two results are offset.

Two protections are built in. A parent will never be ordered to pay more than they would have if all the children lived with the other parent. And where the formula would require a parent with more than half the overnights to pay support, that parent may show the result is inappropriate.

Where each parent has physical custody of at least one child, Rule 120(i)(6) applies a parallel split-custody calculation with offsetting obligations. And where a parent with 25% or less of the overnights has the child for fourteen consecutive days or more, the court may abate support — a reasonable reduction being 50% for the duration.

Health Insurance, Medical Costs, and Childcare

These sit outside the basic obligation and are shared pro rata according to each parent’s share of Guidelines Income. Coverage should be carried by whichever parent can obtain appropriate coverage through an employer at lower cost. Shared costs can include orthodontic, optical, dental, psychological, and prescription expenses.

One provision catches many parents out. Under Rule 120(g)(4)(B), any health care expense that will cost the other parent more than $500 out of pocket for the course of treatment must be approved in advance, in writing, by both parents or by prior court order. Courts may grant relief in extraordinary circumstances, and may consider whether consent was unreasonably requested or unreasonably withheld — but the safe course is to get it in writing first.

Work-related childcare is not covered by the basic calculation either. The court may order it shared in proportion to income.

When Child Support Ends

Support runs until the child turns 18. Under Idaho Code § 32-706(2), if the child is still in high school the court may, in its discretion, continue support until they finish high school or turn 19, whichever comes first. Continuation is not automatic, and a child who turns 19 mid-year loses support at 19.

Idaho does not order support for college. Rule 120(a) states that support for education following high school is not available under the Guidelines.

Where there is more than one child, the order must be written as a stair-step. When one child ages out, the amount does not simply drop by a proportional share — it resets to the scheduled figure for the remaining number of children.

Modifying Child Support

Idaho Code § 32-709(1) permits modification only on a showing of a substantial and material change of circumstances, and only as to installments accruing after the motion is filed. That second limit is absolute: arrears that built up before you filed cannot be modified away, so delay in filing is expensive.

A widely repeated error is worth correcting. You may read that Idaho requires a 15% change before support can be modified. That figure is real but it is not a filing threshold and it does not appear in the Guidelines. Idaho Code § 32-1218(3) provides that the Department of Health and Welfare will only pursue a modification where review shows a difference of at least 15%, and not less than $50 per month. That is the agency’s internal screening standard for cases it enforces. A privately filed motion is governed solely by the substantial-and-material standard.

In department-enforced cases, parents must be notified of the right to request review every 36 months, and more frequently on a substantial and material change such as a change in income, a change in the child’s needs, or a change in custody. Children born or adopted after the existing order was entered are not considered in a modification.

Enforcement

Idaho support orders are backed by mandatory income withholding under Title 32, Chapter 12, and every support order must notify the paying parent that it will be enforced this way. Beyond withholding, the tools available include:

Contempt proceedings for disobedience of a court order.
License suspension under Title 7, Chapter 14 — and the reach is deliberately broad. It covers professional and occupational licenses, driver’s licenses, concealed weapons permits, and recreational licenses including hunting and fishing. The trigger is a delinquency equal to 90 days of support, or $2,000, whichever is less.
State tax refund intercept through the Idaho State Tax Commission. On a joint return the non-obligated spouse may protest, and the set-off is limited to one-half of the refund.
Lottery prize offset, liens, account garnishment, credit bureau reporting, PERSI retirement intercept, and passport denial.

There is effectively no statute of limitations while the judgment lives. Idaho Code § 5-245 allows an action to collect arrears at any time before the resulting judgment or any renewal of it expires.

The Department of Health and Welfare’s Child Support Services will establish, modify, and enforce support — and its services are available whether or not you receive public assistance. It cannot, however, help with custody or parenting time.

Back support

In a paternity case, Idaho Code § 7-1121(2) allows the court to order support for the period before the order of filiation, plus the mother’s pregnancy and confinement expenses. Where a genetic test shows a probability of at least 98%, temporary support is mandatory on motion while the case proceeds. During a divorce, Idaho Code § 32-704 allows temporary support while the case is pending.

Idaho Code § 32-709(2) also permits a credit against arrears where the children have lived primarily with the paying parent for more than 120 days, with the custodial parent’s knowledge and consent.

Low-Income Cases

Idaho has no formal self-support reserve. Instead, Rule 120(c)(4) directs that support should rarely be set at zero, and that where the paying parent’s monthly income is below $800, the court should review incomes and living expenses carefully to set the maximum support possible without denying that parent the means of self-support at a minimum subsistence level. There is a rebuttable presumption of at least $50 per month, per child.

FAQ

When does Idaho child support end?

Generally at age 18, or upon high school graduation up to age 19 if the child is still enrolled. Support for a disabled child can extend beyond these limits.

Can child support be waived?

No. The right to child support belongs to the child, not the parent, and cannot be permanently waived by agreement. Courts will not approve decrees that fail to provide for child support consistent with the guidelines.

Talk to a Boise Family Law Attorney

Call (208) 696-2772 for a confidential consultation. We serve clients across Boise, Meridian, Nampa, Caldwell, Eagle, Star, and the entire Treasure Valley.

Family law representation is offered exclusively in Idaho. Submitting a contact form does not create an attorney-client relationship.