Iowa Child Support Guidelines

Iowa calculates child support using the income shares model, which is based on the idea that children should receive the same proportion of parental income they would have received if the family stayed together. The Iowa Child Support Guidelines are established under Iowa Court Rule 9.4 and apply to all child support cases unless the court finds specific reasons to deviate from the calculated amount.

This article explains how Iowa’s guidelines work step by step. For a national overview, see our guide on how child support is calculated.

How the Income Shares Model Works

Iowa’s income shares model estimates the total cost of raising a child at the parents’ combined income level, then divides that cost proportionally. The basic steps are:

1. Calculate each parent’s monthly net income
2. Add both net incomes together to get the combined net income
3. Look up the basic support obligation in the Iowa guidelines table based on combined net income and the number of children
4. Divide the basic obligation between the parents based on each parent’s percentage share of combined income
5. Add adjustments for health insurance, childcare, and medical support
6. The noncustodial parent’s share becomes the child support order

The guidelines create a rebuttable presumption — the calculated amount is presumed to be correct unless a party demonstrates that applying the guidelines would be unjust or inappropriate.

Calculating Net Income

Iowa uses net income rather than gross income as the starting point. Net income is calculated by taking gross income and subtracting specific mandatory deductions.

What Counts as Income

Income includes all earnings and revenue from any source, including wages, salaries, tips, commissions, bonuses, overtime pay, self-employment income, interest, dividends, investment income, rental income, pension and retirement benefits, Social Security benefits (excluding SSI), workers’ compensation, disability payments, unemployment benefits, spousal support received, trust income, and military pay.

Allowable Deductions

The following are subtracted from gross income to arrive at net income:

• Federal and state income taxes
• FICA (Social Security and Medicare taxes)
• Mandatory pension contributions required by the employer
• Union dues (if mandatory)
• Health insurance premiums for the parent only (the children’s portion is handled separately)
• Prior child support obligations being paid under a court order
• Spousal support paid under a court order

Voluntary retirement contributions, personal loan payments, and credit card debt are generally not deducted.

The Iowa Guidelines Table

Iowa publishes a child support guidelines schedule that lists the total support obligation based on the parents’ combined monthly net income and the number of children. The table covers a wide range of income levels and specifies the dollar amount both parents should contribute to support one child, two children, three children, and so on.

How the table works: Find the row matching the combined monthly net income, then the column for the number of children. The number at that intersection is the total basic support obligation.

Example: If combined monthly net income is $6,000 and there are two children, the table might show approximately $1,320 per month. If Parent A earns $3,600 (60%) and Parent B earns $2,400 (40%), Parent A is responsible for 60% of the obligation ($792). If Parent B has primary physical care, Parent A pays that share to Parent B.

Health Insurance and Medical Support

Health Insurance Premiums

The cost of health insurance premiums attributable to the children is added to the basic support obligation and divided between the parents based on their income shares. The parent who carries the insurance receives credit for the children’s portion of the premium.

Iowa law requires that the court address health insurance in every child support order. If affordable health insurance is available through either parent’s employer, the court typically orders the parent with the better or more affordable coverage to maintain it.

Medical Support

In addition to health insurance, Iowa requires medical support provisions in child support orders. This includes:

• Responsibility for unreimbursed medical expenses — copays, deductibles, prescriptions, dental work, orthodontia, vision care, and therapy
• These costs are typically divided between the parents in proportion to their net incomes
• Many Iowa orders specify a threshold (such as $250 per year per child) for ordinary unreimbursed expenses, with costs above that threshold divided proportionally

Childcare Expenses

Reasonable childcare expenses incurred because a parent is working, seeking work, or attending school are added to the basic obligation and divided proportionally.

The childcare costs must be for actual childcare — daycare, before- and after-school programs, or summer care. The net cost is used, meaning any subsidies, tax credits, or employer contributions are subtracted first.

Shared Physical Care Adjustments

Iowa’s guidelines provide adjustments based on the amount of parenting time each parent exercises.

Extraordinary Visitation Credit (128+ Overnights)

When the noncustodial parent exercises 128 or more overnights per year, the guidelines provide an extraordinary visitation credit — a percentage reduction to the noncustodial parent’s share of the basic support obligation. The credit increases with more overnights: 15% for 128–147 overnights, 20% for 148–166 overnights, and 25% for 167 or more overnights. This credit applies within the standard sole physical care worksheet.

Joint (Shared) Physical Care

When both parents have joint physical care — meaning the child spends roughly equal time with each parent (approximately 183 overnights per year each) — the guidelines use a different worksheet. Each parent’s support obligation to the other is calculated based on their income shares, and the two amounts are offset. The parent with the higher income pays the difference to the other parent, resulting in a lower transfer amount than in a sole physical care arrangement.

Example: If Parent A’s obligation would be $1,000 per month and Parent B’s would be $400, the offset results in Parent A paying $600 per month.

Minimum Support Order

Iowa’s guidelines establish a minimum child support obligation. Even when the calculated amount falls below a certain threshold, the court generally orders at least the minimum. Parents with extremely low income may petition for a deviation, but the court must make specific findings to justify setting support below the minimum.

Deviation Criteria

While the guidelines amount is presumed correct, the court can deviate from it if applying the standard calculation would be unjust or inappropriate. Iowa Court Rule 9.11 lists factors the court considers when deciding whether to deviate:

• The child’s special needs beyond typical costs
• Tax consequences to each parent
• Extraordinary visitation expenses (such as long-distance travel costs)
• The child’s own income or assets
• Prior support obligations for other dependents
• Benefits received by the child (such as Social Security derivative benefits)
• Agreement of the parties (subject to court approval)

The court must document its reasons for any deviation.

Modification of Child Support

Either parent can petition the court to modify an existing child support order when there has been a substantial change in circumstances. Iowa applies a specific threshold: a modification is generally warranted when the recalculated amount differs from the current order by 10% or more.

Common grounds for modification include:

• A significant increase or decrease in either parent’s income (job loss, raise, new employment, retirement, or disability)
• A change in the custody or physical care arrangement
• A change in the children’s needs — for example, new medical expenses or the child reaching school age and reducing childcare costs
• A change in health insurance availability or cost
• Emancipation of one child in a multi-child order

How to Request a Modification

To modify child support, you file a petition with the court that issued the original order. You must demonstrate the substantial change and provide updated financial information. The Iowa Child Support Recovery Unit (CSRU) can also initiate a review every three years or when a parent requests one. Modifications take effect from the filing date, not retroactively — past-due support cannot be reduced after the fact.

Duration of Child Support

Iowa child support generally continues until the child turns 18 or graduates from high school (whichever is later), but not past age 19. Support may continue beyond 18 for a child with a disability that prevents self-support. Under Iowa Code Section 598.21F, the court may order a postsecondary education subsidy upon a showing of good cause. Each parent’s contribution is capped at one-third of the cost of attending an in-state public institution. Iowa is one of a minority of states where courts have statutory authority to order college support.

What to Do Next

If child support is an issue in your Iowa case, take these steps to protect your interests and your children’s needs:

1. Gather complete income records. Collect pay stubs, tax returns, W-2s, 1099s, and documentation of all income sources. The accuracy of the support calculation depends entirely on complete financial information.
2. Track child-related expenses. Document health insurance premiums, unreimbursed medical costs, childcare expenses, and any extraordinary costs related to the children. These adjustments can significantly affect the final support amount.
3. Count overnights carefully. If you have or are seeking shared physical care, the overnight count determines whether the shared care adjustment applies. Keep a detailed record of the actual parenting schedule.
4. Understand the guidelines before negotiating. Run the numbers using Iowa’s guidelines schedule so you know what the calculated amount would be. This gives you a baseline for any discussion or hearing.
5. Consult with an Iowa family law attorney. Child support calculations involve nuances — income definitions, imputed income, deviation factors, shared care adjustments, and medical support. An experienced attorney can ensure the calculation is accurate and your children’s needs are met.

Schedule a free consultation to discuss your Iowa child support questions with an experienced family law attorney.

Frequently Asked Questions

How does Iowa calculate child support?

Iowa uses the income shares model. Both parents’ net incomes are combined, and the guidelines table specifies a total support obligation based on that combined income and the number of children. The obligation is divided between the parents in proportion to their individual incomes. Adjustments are then made for health insurance, childcare, and other expenses.

What is the 10% rule for modifying child support in Iowa?

Iowa uses a 10% threshold for child support modification. If a recalculation based on current circumstances produces an amount that differs from the existing order by 10% or more, the court generally considers this a substantial change warranting modification. Either parent can petition for a review.

Does shared custody affect child support in Iowa?

Yes. When the noncustodial parent exercises 128 or more overnights per year, Iowa provides an extraordinary visitation credit (15%–25% depending on the number of overnights). When both parents have joint physical care (approximately equal time), Iowa uses a different calculation worksheet. Each parent’s support obligation to the other is calculated, and the two amounts are offset. The parent with the higher income typically pays the difference, which results in a lower transfer amount than in a sole physical care arrangement.

What happens if a parent is not working?

If a parent is voluntarily unemployed or underemployed, the court may impute income — attributing earning capacity based on the parent’s education, work history, skills, and the local job market. This prevents a parent from reducing their support obligation by choosing not to work or by working below their capacity.

Can a court order parents to pay for college in Iowa?

Yes. Under Iowa Code Section 598.21F, the court may order a postsecondary education subsidy upon a showing of good cause. Each parent’s share is capped at one-third of the cost of attending an in-state public institution. This is separate from regular child support, which ends at age 18 or high school graduation (whichever is later), and no later than age 19. Parents can also voluntarily agree to share college expenses as part of their divorce settlement.