Alaska Child Support: A Parent's Guide

In short: Alaska calculates support under Civil Rule 90.3, applying set percentages to the noncustodial parent's adjusted income, adjusted for the custody split. Modifications require a material change in circumstances, and critically, Alaska generally prohibits retroactive modification, a change typically only applies from the date formal notice of the modification petition went out.

This is an educational overview written for parents, not lawyers. It isn't legal advice. For anything beyond general understanding, talk to a licensed Alaska family law attorney.

What Alaska generally provides

Under Civil Rule 90.3, Alaska applies a percentage of the noncustodial parent's adjusted income based on the number of children: 20% for one child, 27% for two, 33% for three, with 3% added for each additional child, subject to the income cap and custody-arrangement adjustments described in the state's custody guide.

Important terminology

• Rule 90.3: Alaska's governing rule for calculating and modifying child support.
• Material change of circumstances: the standard required for a modification, which can include a significant income or parenting-time shift.
• Retroactive modification prohibition: Rule 90.3(h)(2)'s general bar on changing a support obligation for periods that already passed.

How the calculation works

Applying set percentages to adjusted income

Rule 90.3's core formula applies 20% of adjusted income for one child, 27% for two, and 33% for three, with 3% added for each additional child, run against the noncustodial parent's adjusted income and capped at a set annual figure, with adjustments depending on whether custody is primary, shared, divided, or hybrid.

Applies to essentially every child support proceeding

Rule 90.3 governs all proceedings involving child support, whether temporary or permanent, contested or uncontested, including separation, divorce, dissolution, support modification, domestic violence cases, paternity actions, and Child in Need of Aid and Delinquency proceedings, a genuinely broad scope of application.

Requesting or defending a modification

A modification requires showing a material change of circumstances, which can include a significant change in income or in the parenting time schedule. Critically, under Rule 90.3(h)(2), retroactive modification is generally prohibited, a court can't simply change what was owed for a past period after the fact, to maintain fairness and consistency for both parents. However, when the Child Support Enforcement Division sends formal notice of a modification petition, a resulting increase or decrease can apply back to that notice date, which the rule specifically doesn't treat as retroactive. See the child support calculator and guideline finder for jurisdiction-specific calculation sources and guidance.

How enforcement works

Alaska's Child Support Services Division (CSSD) handles enforcement, including income withholding, with garnishment permitted up to 50% of disposable income for child support. Beyond wage withholding, CSSD has additional collection tools available once a delinquency is identified and the case is in the state enforcement system.

Common questions

If my income drops, does my support amount automatically go down? No, and the retroactive modification ban makes timing especially important in Alaska, you need to file (and the process needs to generate formal notice) before any reduction applies, arrears from before that point remain owed at the original rate.

Does Rule 90.3 apply even in a paternity case, not just divorce? Yes, its scope is broad and covers paternity, domestic violence, and Child in Need of Aid proceedings, not just traditional divorce or separation cases.

What if my co-parent isn't paying? Contact Alaska's Child Support Services Division (CSSD), which can pursue income withholding and other enforcement tools.

Practical considerations

Because Alaska's retroactive modification ban means delay has real financial consequences, if your circumstances change meaningfully, start the modification process as soon as possible rather than waiting, since arrears accrued before the formal notice date generally remain fully owed regardless of when the underlying change actually happened. For the custody and parenting-time rules that factor into the adjusted-income percentage, see the Alaska custody guide.

Official Alaska resources

• Alaska Civil Rule 90.3 (Child Support Awards)
• Alaska Civil Rule 90.3 Commentary

Related OnePage resources

• Child support calculator and guideline finder
• What is a parenting plan
• Custody schedule generator

Related Alaska pages

• Alaska hub
• Alaska custody guide