Quick Answer
The kiddie tax stops applying at age 18 for most children, but continues until age 24 for full-time college students who don't provide more than half their own support. Specifically, it ends the year the child turns 18 (if not a student), or when a student turns 24, provides more than half their support, or stops being a full-time student.
Best Answer
Michelle Woodard, Tax Policy Analyst
Parents with children approaching college age or currently enrolled, trying to understand when kiddie tax rules end
When does kiddie tax stop applying?
The kiddie tax doesn't automatically end at 18. According to IRS Publication 929, it continues until your child meets all of the following conditions:
1. Age 18 or older
2. NOT a full-time student (or if a student, age 24 or older)
3. Provides more than half of their own support
The three age thresholds explained
Children under 18
Kiddie tax always applies to unearned income over $2,600, regardless of support or student status.
Age 18 (not a full-time student)
Kiddie tax stops if the 18-year-old provides more than half their own support. If parents still provide most support, kiddie tax continues.
Ages 19-23 (full-time students)
Kiddie tax continues unless the student provides more than half their own support.
Age 24 and older
Kiddie tax stops regardless of student status or support arrangements.
Example: College student scenarios
Scenario 1: Sarah, age 20, junior at State University
Scenario 2: Michael, age 22, senior at Private College
How to calculate the support test
The support test compares money the child spends on their own support versus total support received from all sources.
Counts as support the child provides:
Counts as support from others:
Support calculation worksheet
Result: Child doesn't provide more than half support, so kiddie tax applies.
Special situations
Graduate students
Most graduate students are over 24, so kiddie tax doesn't apply regardless of support.
Medical/law school students
Students in professional programs often qualify for the support exception through student loans, even if parents help with living expenses.
Gap year students
A child taking a gap year after high school is no longer a "student" for kiddie tax purposes, so the tax stops at age 18 if they provide their own support.
Part-time students
Part-time enrollment doesn't count as "full-time student" status, so kiddie tax stops at 18 (with support test).
What you should do
1. Track support contributions carefully: Keep records of who pays what for college expenses
2. Consider loan strategies: Student loans count as support the child provides to themselves
3. Time investment sales: Realize capital gains after kiddie tax rules end
4. Review annually: Student status and support arrangements can change each year
5. Plan for senior year: Many students start providing their own support through jobs and loans
Use our refund estimator to calculate potential tax savings when kiddie tax rules no longer apply to your child's investments.
Key takeaway: Kiddie tax ends at 18 for non-students who support themselves, but continues through age 23 for full-time college students unless they provide more than half their own support. Age 24 is the absolute cutoff regardless of circumstances.
Key Takeaway: Kiddie tax ends at 18 for non-students who support themselves, but continues through age 23 for full-time college students unless they provide more than half their own support.
When kiddie tax stops applying based on age, student status, and support
| Age | Student Status | Support Test | Kiddie Tax Applies? |
|---|---|---|---|
| Under 18 | Any | Any | Yes, always |
| 18 | Not a student | Provides >50% own support | No |
| 18 | Not a student | Provides <50% own support | Yes |
| 19-23 | Full-time student | Provides >50% own support | No |
| 19-23 | Full-time student | Provides <50% own support | Yes |
| 19-23 | Not a student | Provides >50% own support | No |
| 24+ | Any | Any | No, never |
More Perspectives
Michelle Woodard, Tax Policy Analyst
Divorced parents navigating kiddie tax rules while sharing college expenses and support responsibilities
Kiddie tax age limits with divorced parents
When parents are divorced, determining when kiddie tax ends becomes more complex because support calculations must account for contributions from both parents, plus any support the child provides.
Support test with two households
Combined support calculation: Add up support from both parents plus what the child provides to determine if the child meets the "more than half" test.
Example: 21-year-old college student Emma
Which parent's tax return?
Even when kiddie tax applies, divorced parents must determine whose return includes the kiddie tax calculation. Generally, it's the custodial parent (who claims the child as a dependent), regardless of which parent's income generated the investment returns.
Common planning mistakes
1. Not coordinating expenses: Each parent tracks their own contributions but doesn't communicate about the total support picture
2. Overlooking loan proceeds: Student loans count as support the child provides, even if parents cosign
3. Misunderstanding custody vs. support: The parent claiming the child as a dependent handles kiddie tax, but support comes from both parents
Key takeaway: With divorced parents, combine support from both households to determine if the child provides more than half their total support, but file the kiddie tax calculation with the custodial parent's return.
Key Takeaway: With divorced parents, combine support from both households to determine if the child provides more than half their total support, but file the kiddie tax calculation with the custodial parent's return.
Diana Flores, Tax Credits & Amendments Specialist
Grandparents who are supporting or have custody of grandchildren in college
Kiddie tax age limits for grandchildren
When grandparents are involved in supporting college-age grandchildren, the kiddie tax age rules work the same way, but the support calculations often look different.
Grandparent as primary support provider
If grandparents have legal custody or provide the majority of support:
Three-generation support scenario
Example: 22-year-old college student with involved grandparents
Estate planning considerations
Grandparents often transfer investment assets to grandchildren, but should consider timing:
Many grandparents benefit from waiting until the grandchild turns 24 or becomes self-supporting before transferring high-income investments.
Key takeaway: Grandparents should coordinate with parents to track total support provided to college-age grandchildren, as the combined family support often prevents students from meeting the self-support test needed to escape kiddie tax.
Key Takeaway: Grandparents should coordinate with parents to track total support provided to college-age grandchildren, as the combined family support often prevents students from meeting the self-support test.
Sources
- IRS Publication 929 — Tax Rules for Children and Dependents
- IRS Publication 501 — Dependents, Standard Deduction, and Filing Information
Related Questions
Reviewed by Michelle Woodard, Tax Policy Analyst on February 28, 2026
This content is for educational purposes only and is not a substitute for professional tax advice. Consult a qualified tax professional for advice specific to your situation.