What Is IRC 151? Personal Exemptions and Dependents

IRC Section 151 is the federal statute that once allowed you to deduct a personal exemption for yourself, your spouse, and each dependent. The IRC 151 personal exemption amount is now permanently set at zero dollars, so the deduction itself no longer reduces your taxable income. The dependent definitions attached to Section 151 through Section 152 still matter, because they control who qualifies you for the Child Tax Credit, the Credit for Other Dependents, Head of Household filing status, and the Earned Income Tax Credit.

How the Exemption Went to Zero and Stayed There

For 2017, the last year the exemption had value, taxpayers subtracted $4,050 per person from taxable income. A family of four filing jointly wiped out $16,200 before applying the standard deduction.

The Tax Cuts and Jobs Act, enacted in late 2017, reduced the exemption amount to zero for tax years 2018 through 2025. The provision was scheduled to sunset, and the exemption would have returned in 2026 at roughly $5,300 per person. To offset the loss, Congress roughly doubled the standard deduction and expanded the Child Tax Credit from $1,000 to $2,000 per child.¹

The scheduled return never happened. On July 4, 2025, the One, Big, Beautiful Bill Act amended IRC 151(d)(5) by striking the end date. The statute now sets the exemption at zero for all tax years beginning after December 31, 2017, with no expiration. The larger standard deduction was made permanent and further increased.²

For 2026 and beyond, there is no personal exemption line on your return, and no deduction to claim for yourself or your dependents. The deduction is gone for good.

Why Dependent Status Still Matters

A worthless deduction does not make dependent status worthless. Claiming a person as a dependent is the gateway to several credits and a better filing status, each of which can cut your actual tax bill by hundreds or thousands of dollars.

Child Tax Credit: up to $2,000 per qualifying child under age 17, with a partially refundable portion through the Additional Child Tax Credit.³
Credit for Other Dependents: a $500 nonrefundable credit for dependents who don’t qualify for the Child Tax Credit, such as children aged 17 or older, dependent parents, or dependents with an ITIN.⁴
Head of Household filing status: available to unmarried taxpayers who pay more than half the cost of maintaining a home for a qualifying dependent, and it provides a larger standard deduction and wider brackets than filing single.⁵
Earned Income Tax Credit: qualifying children increase both the maximum credit and the income level at which you can still claim it.⁶

Every dependent needs a taxpayer identification number. To claim the Child Tax Credit, the child must have a valid SSN issued before the due date of your return. A dependent with only an ITIN can still generate the $500 Credit for Other Dependents, but not the Child Tax Credit.⁷

Who Counts as a Qualifying Child

IRC Section 152(c) sets out five tests, and all five must be met.⁸

Relationship: your child, stepchild, foster child, sibling, stepsibling, or a descendant of any of these (a grandchild, niece, or nephew).⁹
Age: under 19 at year end, or under 24 if a full-time student. No age limit if the person is permanently and totally disabled.
Residency: lived with you more than half the year. Temporary absences for school, medical care, or military service don’t break residency.
Support: the child did not provide more than half of their own support during the year.
Joint return: the child did not file a joint return for the year, unless it was filed only to claim a refund of withheld taxes.

The Child Tax Credit uses a stricter age cutoff than the general dependent test. The child must be under 17 at year end to generate the $2,000 credit. A 17-year-old can still be your qualifying child for dependency purposes and produce the $500 Credit for Other Dependents.³

Who Counts as a Qualifying Relative

When a person doesn’t meet the qualifying child tests, four different tests decide whether they can be your qualifying relative. This is the category that covers parents, adult siblings, and unrelated household members.⁸

Not a qualifying child of anyone. If your 20-year-old niece could be her parents’ qualifying child, you cannot claim her as a qualifying relative even if you support her.
Relationship or household. The person is either related to you in a way the statute recognizes (parent, sibling, in-law, aunt, uncle, and others) or lived in your home as a member of the household for the entire year.
Gross income under the annually adjusted threshold, which is $5,300 for 2026.⁹
Support. You provided more than half of the person’s total support during the year, counting housing, food, clothing, medical care, education, and similar necessities.

Qualifying relatives never generate the Child Tax Credit, regardless of age. They can generate the $500 Credit for Other Dependents and can support Head of Household filing if the other requirements for that status are met.

When More Than One Person Could Claim the Same Dependent

Divorced parents, blended families, and multi-generational households often find that more than one person meets the tests to claim the same child. The IRS resolves these conflicts through tie-breaker rules.¹⁰

Parent versus non-parent: the parent wins.
Two parents not filing jointly: the parent the child lived with longer during the year.
Equal time with both parents: the parent with the higher adjusted gross income.
No parent claims the child: a non-parent may claim the child only if that non-parent’s AGI is higher than the highest AGI of any parent who could have claimed the child.
No parent is in the mix at all: the person with the highest AGI.

Divorced or separated parents can also shift the claim by agreement. The custodial parent signs IRS Form 8332 to release the claim to the noncustodial parent, who can then claim the Child Tax Credit. The custodial parent typically keeps the ability to file as Head of Household and claim the EITC based on that child.¹¹

What Happens If You Claim a Dependent You Shouldn’t

The IRS catches these errors more often than people expect, in part because two returns claiming the same Social Security number as a dependent both get flagged.

An honest mistake usually means repaying the credits you received plus interest. Negligence or reckless disregard of the rules triggers an accuracy-related penalty equal to 20% of the underpaid tax.¹²

Credit-specific bans are harsher. A reckless or intentional disregard finding on an EITC claim blocks you from taking the credit for two years. Fraud extends the ban to ten years.¹³ The same ban periods apply to the Child Tax Credit and other credits.¹⁴

Deliberately filing a false return that includes a fraudulent dependent claim is a felony, carrying a potential fine of up to $100,000 and up to three years in prison.¹⁵

1
Office of the Law Revision Counsel. 26 USC 151 – Allowance of Deductions for Personal Exemptions
2
Office of the Law Revision Counsel. 26 U.S. Code 151 – Allowance of Deductions for Personal Exemptions
3
Internal Revenue Service. Child Tax Credit
4
Internal Revenue Service. Parents – Check Eligibility for the Credit for Other Dependents
5
Internal Revenue Service. Filing Status
6
Internal Revenue Service. Who Qualifies for the Earned Income Tax Credit (EITC)
7
Internal Revenue Service. Dependents
8
Office of the Law Revision Counsel. 26 USC 152 – Dependent Defined
9
Internal Revenue Service. Dependents
10
Internal Revenue Service. Publication 501 – Dependents, Standard Deduction, and Filing Information
11
Internal Revenue Service. Filing Status
12
Office of the Law Revision Counsel. 26 USC 6662 – Imposition of Accuracy-Related Penalty on Underpayments
13
Office of the Law Revision Counsel. 26 USC 32 – Earned Income
14
Internal Revenue Service. Consequences of Not Meeting the Due Diligence Requirements
15
Office of the Law Revision Counsel. 26 U.S. Code 7206 – Fraud and False Statements