Preliminary Work with Taxpayer Data
Filing status and dependency
Preliminary work begins with facts: identity, age, blindness, marital status on December 31, residence, and who paid whose support. Filing status drives rates, the standard deduction, and credit eligibility. The five statuses are single, married filing jointly (MFJ), married filing separately (MFS), head of household (HOH), and qualifying surviving spouse (QSS). HOH requires an unmarried or considered-unmarried taxpayer who paid more than half the household costs for a qualifying person and whose spouse did not live in the home for the last six months. QSS requires a dependent child and the same household-cost test, and lasts only two years after the year of death.
Dependency splits into qualifying child (relationship, age, residence, support) and qualifying relative (not a qualifying child, gross income under the threshold, support over half). A qualifying child must be under 19, or under 24 and a full-time student, or permanently disabled, and cannot provide over half of their own support. MFS taxpayers must both itemize or both take the standard deduction.
Traps. Questions bait you with an extension: filing by October 15 does not extend the payment deadline. Support is measured by actual payments, not promises. Scholarship funds used for tuition generally are not support provided by the student. Tie-breaker rules resolve a child claimed by two parents.
Rule of thumb. Due date April 15; automatic extension to file, not to pay, until October 15; three-year assessment statute, six years if gross income is understated by more than 25%.
Worked example. A parent pays $9,000 of a child's $15,000 total support; the child's wages cover $4,000 and scholarships $2,000. The parent provided 60% and meets the support test.