When must a child meet the age test to be claimed as a qualifying child?

To determine whether a child can be claimed as a qualifying child, the age test is applied as of December 31 of the tax year in question. This means that the child must be under a certain age—typically under 19 or under 24 if they are a full-time student—by the end of the year for which you are filing.

Meeting this requirement ensures that the child is considered a dependent for that tax year, allowing the taxpayer to take advantage of various tax benefits associated with dependents, such as tax credits and deductions. Therefore, it is crucial to establish the child’s age on that specific date, which is why this answer is the most accurate in defining when the age test must be met. Other options regarding different timelines or periods do not align with the specific stipulation of the tax code related to dependency qualifications.