UTMA / UGMA Kiddie Tax Calculator
Calculate the kiddie tax on UTMA, UGMA, and other custodial account unearned income for 2026 using IRS Form 8615 thresholds. See how much is taxed at the child's rate, the parent's rate, and the total tax owed — free, private, and instant.
What Is the Kiddie Tax and Why Does It Exist?
The kiddie tax was created in 1986 to stop wealthy parents from shifting investment income to their children to exploit the children's lower tax brackets. Per the IRS Form 8615 instructions, a child's unearned income (interest, dividends, capital gains, royalties from custodial accounts) above $2,700 in 2026 is taxed at the parent's marginal tax rate instead of the child's. The first $1,350 is tax-free (covered by the child's standard deduction for unearned income), the next $1,350 is taxed at the child's 10% bracket, and everything above $2,700 is taxed at the parent's rate. This eliminates the bracket-shifting strategy for income beyond modest amounts.
UTMA vs UGMA — What Triggers the Kiddie Tax
Uniform Transfers to Minors Act (UTMA) and Uniform Gifts to Minors Act (UGMA) accounts are custodial brokerage accounts owned by a minor but managed by an adult custodian until the child reaches the age of majority (18-21 depending on state). Income generated within these accounts — interest from CDs, dividends from index funds, realized capital gains from selling appreciated securities — is the child's unearned income for tax purposes. The parent reports the income on the child's return (Form 8615) or, if income is under $13,500 and consists only of interest and dividends, on the parent's return using Form 8814. Per the IRS Publication 929, the parent must compare both methods to choose the lower-tax option.
2026 Kiddie Tax Thresholds and Strategies
For 2026, the IRS-adjusted unearned income thresholds are: $1,350 tax-free standard deduction for unearned income, $1,350 next dollar taxed at 10% child rate, $2,700+ taxed at parent's marginal rate. Strategies to manage kiddie tax: (1) Hold growth assets, defer realization — unrealized capital gains do not trigger kiddie tax, so buy-and-hold index funds in a UTMA can grow tax-free until liquidation in adulthood. (2) Realize gains in low-parent-income years — if a parent has a sabbatical or business loss year, that's the time to harvest UTMA gains. (3) Switch to a 529 plan for education expenses — 529 growth is federally tax-free if used for qualified education. The kiddie tax applies through age 17, or through age 23 for full-time students whose earned income is less than half their support. Last updated May 2026.
When to Use Form 8814 vs Form 8615
Two forms allow parents to handle a child's unearned income: Form 8814 (parent elects to include child's income on parent's return) requires the child to be under 19 (or under 24 if a full-time student), have unearned income only from interest and dividends, total unearned income under $13,500 in 2026, and no estimated tax payments made in the child's name. Form 8615 (kiddie tax on the child's separate return) is used in all other cases or when election to Form 8814 is undesirable. Form 8814 is simpler but pushes the child's income into the parent's AGI, which can trigger phaseouts of education credits, the Net Investment Income Tax 3.8%, IRMAA Medicare premium surcharges, and other AGI-based items. Run the numbers both ways before choosing — sometimes the additional complexity of Form 8615 saves $1,000+ in cascading effects.
Frequently Asked Questions
What is the kiddie tax threshold for 2026?
The first $1,350 of a child's unearned income is tax-free. The next $1,350 is taxed at the child's 10% rate. Unearned income above $2,700 is taxed at the parent's marginal rate using Form 8615.
Does the kiddie tax apply to earned income?
No. Wages from a real job (W-2 income) are taxed at the child's normal rates, not the parent's rate. The kiddie tax applies only to unearned income from custodial accounts, trusts, and similar passive sources.
What ages does the kiddie tax apply to?
Children under 18 always face the kiddie tax. Children ages 18-23 face the kiddie tax if they are full-time students AND their earned income is less than half their support. After age 23 (or after college if not a full-time student), the kiddie tax no longer applies.
Should I use Form 8814 or Form 8615?
Form 8814 (election to include child's income on parent's return) is simpler but pushes income into parent's AGI, potentially triggering credit phaseouts, NIIT, and Medicare IRMAA. Form 8615 keeps income on the child's separate return. Calculate both — Form 8615 often saves money for high-income parents despite the extra form.
Are 529 plans subject to kiddie tax?
No. 529 plan investment growth is federally tax-deferred and tax-free if used for qualified education expenses (tuition, books, room and board, K-12 up to $10K/year). 529s are owned by the parent (or grandparent) and the beneficiary is the child, so they are not custodial accounts subject to kiddie tax.
Can I avoid the kiddie tax by holding growth stocks?
Partially. Unrealized capital gains do not trigger kiddie tax — only realized (sold) gains do. A buy-and-hold index fund strategy in a UTMA can defer kiddie tax until the child reaches adulthood and liquidates, at which point gains are taxed at the (former-child's) own rate.