What is the criteria for a child under 24 to be subjected to kiddie tax rules?

The principle behind the kiddie tax rules is designed to prevent parents from shifting income to their children to benefit from the child's lower tax rate. For a child under the age of 24, one key criterion is that they must not file a joint return. This is important because if the child files a joint return, they may not be subjected to the kiddie tax provisions, which are meant to apply to dependent children who meet specific income thresholds.

When a child does not file jointly, it indicates that they are likely still dependent and qualifying for the kiddie tax regulations, allowing the IRS to tax their unearned income (like interest, dividends, or capital gains) at the parents' tax rate if it exceeds certain amounts.

The other options, while they touch on related aspects of a child's financial situation, do not directly address the filing status that is crucial for the kiddie tax application. For instance, simply having earned income exceeding half of their support or being a part-time student does not inherently affect the applicability of the kiddie tax rules, nor does having unearned income below a specific limit directly determine whether the rules apply without considering the filing status.