The Affordable Care Act
The Affordable Care Act, passed in 2010, allows children coverage under their parent's health insurance plan until they turn 26 years old. Children and young adults can join a parent's plan up to age 26, regardless of their marriage, living, school or financial status. The one exception to the act is for group plans that are considered "grandfathered." Until 2014, the grandfathered employer health plan doesn't have to cover dependents up to age 26 if they have coverage elsewhere. If you aren't sure about your plan's status, contact the health plan or your human resources department.
The Affordable Care Act applies to all states. However, states may have their own laws regarding extending the age that young adults can remain on their parent's health insurance plan. States can adhere to these laws unless they conflict with the Affordable Care Act. As of June 2010, 37 states had laws extending the age that children can remain on their parent's plan. Age and requirements vary state by state; certain states extend the limit even later, such as Pennsylvania, which extends this benefit to age 30 for an unmarried child with no dependents who lives in Pennsylvania or is a full-time student.
Primary and Secondary Coverage
Dependent children may have primary and secondary health insurance, coverage through each parent's plan. If parents are married, health plans follow the birthday rule, in which the parent with the earliest birthday month and day — not year — provides primary health insurance to the child. When both parents have the same birthday, the parent who's been on the health plan the longest provides primary coverage. If divorced, the divorce decree specifies which parent provides primary health insurance to the children. Typically, the parent the court deems more financially stable is responsible for the children's health insurance.
Between the Affordable Care Act and state laws, if a parent has group health insurance, so do the children. When parents have individual health insurance, they can add dependents, per state laws. When parents don't have health insurance and don't qualify for state-sponsored medical assistance plans, their children can get health insurance through their state's Children's Health Insurance Program, or CHIP. CHIP's funding is federal- and state-based, and the program is designed to ensure no child goes uninsured.