Understanding the Kiddie Tax and UTMA Account Implications

A parent opens a custodial UTMA account for their 14-year-old, transfers $50,000 of appreciated stock, and the child sells it — expecting to pay the 0% long-term capital gains rate since the child has no other income. Instead, the IRS taxes the gain at the parent's 37% rate. The kiddie tax exists precisely to prevent this strategy, and it catches families who thought they'd found a simple way to shift investment income to a lower-bracket family member.

TL;DR: The kiddie tax requires that unearned income above $2,500 (for 2025) for children under 19 — or full-time students under 24 — be taxed at the parent's marginal rate, not the child's rate. This eliminates the tax benefit of shifting investment income to custodial accounts (UTMA/UGMA) for most families. The first $1,250 of unearned income is tax-free, the next $1,250 is taxed at the child's rate, and everything above $2,500 is taxed at the parent's rate.

How the Kiddie Tax Works

The kiddie tax applies to unearned income (investment income) — not earned income from a job. A teenager earning $15,000 from a summer job is taxed normally at their own rate. But dividends, interest, and capital gains in their custodial account follow different rules.

2025 Thresholds

So a child with $5,000 in investment income pays:

• $0 on the first $1,250
• ~$125 on the next $1,250 (10% rate)
• $925 on the remaining $2,500 (at the parent's 37% rate)
• Total: $1,050 instead of $375 if all taxed at the child's rate

The point is: the kiddie tax creates a hard ceiling on the tax benefit of custodial accounts. Once a child's unearned income exceeds $2,500, every additional dollar is taxed as if the parent earned it.

Who the Kiddie Tax Applies To

The kiddie tax applies to a child who meets all of these criteria:

1. Under age 19 at the end of the tax year, OR under age 24 and a full-time student
2. Has unearned income exceeding $2,500 (2025)
3. Does not file a joint return with a spouse
4. Has at least one living parent

The Age 19/24 Distinction

The original kiddie tax only applied to children under 14. Congress expanded it twice — first to under 18, then to under 19 (or under 24 for full-time students) — specifically to close the loophole of parents shifting income to older teenagers.

Once a child turns 19 (or 24 if a full-time student), the kiddie tax no longer applies. At that point, they're taxed on investment income at their own rate — which may be the 0% long-term capital gains rate if their income is low enough.

KEY INSIGHT: The kiddie tax disappears entirely once the child turns 19 (non-student) or 24 (full-time student). For families with UTMA accounts holding appreciated assets, the optimal strategy is often to wait until the child ages out of the kiddie tax before selling appreciated positions.

UTMA and UGMA Accounts: The Custodial Account Trap

UTMA (Uniform Transfers to Minors Act) and UGMA (Uniform Gifts to Minors Act) accounts are custodial accounts where a minor is the legal owner of the assets, but a custodian (usually a parent) manages the account until the child reaches the age of majority (18 or 21, depending on the state).

The Tax Problem

Assets in UTMA/UGMA accounts belong to the child. All income — dividends, interest, and capital gains — is reported on the child's tax return. The kiddie tax then applies to unearned income above $2,500, taxing it at the parent's rate.

This creates a worst-of-both-worlds situation:

• You can't claim the income on your own return (it's the child's)
• It's taxed at your rate anyway (through the kiddie tax)
• You've given up control of the asset — the child gets full control at age of majority
• It counts against the child's financial aid eligibility — UTMA/UGMA assets are assessed at 20% for FAFSA

Why this matters: parents who opened custodial accounts expecting tax benefits often find that the kiddie tax eliminates those benefits while creating permanent control and financial aid problems.

How This Plays Out With Common Holdings

Dividend-paying stocks in a UTMA: Even modest positions can generate enough dividends to trigger the kiddie tax. A $100,000 position yielding 3% generates $3,000 in dividends — $500 above the threshold, taxed at the parent's rate.

Growth stocks sold for college expenses: Selling appreciated stock in a UTMA to pay for college tuition triggers capital gains taxed at the parent's rate (if the child is a full-time student under 24). A $30,000 gain could result in $7,000+ in tax at the parent's 24% bracket.

Index funds with capital gain distributions: Even without selling, mutual fund and ETF distributions can push a custodial account above the $2,500 threshold in a good market year.

Form 8615 (And the Parent's Return Option)

Children subject to the kiddie tax report it on Form 8615 (Tax for Certain Children Who Have Unearned Income), attached to their own Form 1040.

Alternatively, if the child's only income is interest and dividends totaling less than $12,500 (2025), the parent can elect to report the child's income on the parent's return using Form 8814. This avoids filing a separate return for the child but may not always produce the lowest tax result — run the numbers both ways.

Which Parent's Rate Applies

If parents are married filing jointly, the MFJ tax rate applies. If parents are divorced or separated, the kiddie tax uses the rate of the custodial parent (the parent with whom the child lived for the greater part of the year). If the custodial parent is remarried, the step-parent's income is included.

Strategies to Minimize the Kiddie Tax Impact

1. Keep Unearned Income Below $2,500

The simplest strategy: manage the custodial account to generate less than $2,500 in annual unearned income. This means:

• Favor growth stocks over dividend stocks (unrealized appreciation isn't unearned income)
• Use tax-efficient ETFs instead of mutual funds to minimize distributions
• Avoid selling appreciated positions until the child ages out

2. Invest in Tax-Exempt Municipal Bonds

Municipal bond interest is excluded from unearned income for kiddie tax purposes. A custodial account invested in munis can generate income without triggering the kiddie tax — though the yields are typically lower than taxable alternatives.

3. Use Series I Savings Bonds

Interest on I Bonds can be deferred until redemption. By deferring the interest until the child is no longer subject to the kiddie tax, you avoid the parent's rate entirely. When the child redeems the bonds after age 19 (or 24), the accumulated interest is taxed at the child's own rate.

4. Wait to Sell Until After the Kiddie Tax Ends

If the UTMA holds appreciated assets, delay selling until the child turns 19 (non-student) or graduates/turns 24 (student). At that point, the child's own rate applies — potentially 0% for long-term gains if the child has low income.

5. Consider 529 Plans Instead

For education savings, 529 plans avoid the kiddie tax entirely — earnings grow tax-free and withdrawals for qualified education expenses are tax-free. Assets in 529 plans also receive more favorable financial aid treatment (assessed at 5.64% as parent assets, versus 20% for UTMA/UGMA as student assets).

REMEMBER: If you haven't yet opened a custodial account and the goal is education savings, a 529 plan is almost always superior to a UTMA/UGMA from both tax and financial aid perspectives. The UTMA's only advantage is that funds can be used for anything — not just education.

Converting UTMA to 529

Some states allow you to transfer UTMA/UGMA assets into a custodial 529 plan. The assets remain the child's property (satisfying the irrevocable gift requirement), but future earnings grow tax-free for education purposes. This doesn't undo past taxable income, but it eliminates future kiddie tax exposure on the transferred amount.

The catch: the child still gains control of remaining UTMA funds at the age of majority. And funds transferred to a 529 must be used for qualified education expenses or face the 10% penalty plus tax on earnings.

Earned Income: The Kiddie Tax Exception

The kiddie tax only applies to unearned income. A child's earned income from employment is taxed at the child's own rate, and it's not affected by the parent's income level.

This creates a planning opportunity: if you employ your child in a legitimate business (and pay reasonable compensation), the earned income is:

• Taxed at the child's rate (often 0-10%)
• Exempt from the kiddie tax
• Potentially eligible for a standard deduction ($14,600 for 2025)
• Eligible for IRA contributions (including Roth IRA)

A teenager earning $7,000 from a family business can contribute $7,000 to a Roth IRA — starting tax-free compound growth at age 15 that will grow for 50+ years.

Action Checklist

Essential (know your exposure)

• Check unearned income in any custodial accounts — if it exceeds $2,500, the kiddie tax applies
• Determine the child's age for kiddie tax purposes — under 19, or under 24 if full-time student
• File Form 8615 with the child's return if the kiddie tax applies

High-Impact (reduce kiddie tax)

• Shift to growth-oriented, low-distribution investments in custodial accounts
• Defer selling appreciated positions until the child ages out of the kiddie tax
• Use 529 plans instead of UTMA/UGMA for future education savings

Optional (advanced strategies)

• Convert existing UTMA assets to a custodial 529 if your state allows it
• Employ your teenager in a family business to create earned income eligible for Roth IRA contributions
• Model the breakeven point — at what age and income level does the UTMA become tax-efficient?

Your Next Step

If you have a UTMA or UGMA account for a child, log in and check this year's total dividends, interest, and capital gain distributions. If the total is approaching $2,500, consider whether switching to a tax-efficient growth ETF (like VTI or VOO) would keep the account below the kiddie tax threshold until the child ages out.