Q. I am a 21-year-old dependent living with my parents. I have no wife or kids, so do I apply for health insurance as a household of one and list only my own income? Or do I have to be on my parents’ insurance?
A. You can get your own health insurance policy, but since you’re counted as a dependent on your parents’ tax return, your household income for subsidy purposes will include their income as well, and you’ll be counted as a household of three (or more, if you have siblings who are also dependents on your parents’ tax return). If you are a household of three, subsidy eligibility in 2016 extends up to an income of $80,360 (the 2015 federal poverty guidelines are used for plans with 2016 effective dates, as the 2016 open enrollment period began in 2015). But subsidy eligibility also depends on the cost of health insurance plans in your area.
The family can apply for one health insurance policy with all of you on the same coverage, or you can apply for your own policy. But either way, when it comes to calculating subsidy eligibility, you and your parents are considered one household for tax filing purposes, since they claim you as a dependent on their return. So your combined household income would need to be listed, along with the total number of people in the household.
The same is true for your parents if they are applying for their own health insurance plan for just the two of them; they would still list their household as three people (or more, if they have other dependent children), and include your income along with theirs when applying for premium tax credits.
Here are a few more examples of how this works.