Help Paying Marketplace Premiums: Defining Income and Household

My 24-year-old daughter, who is working, lives near me and my spouse. We do not claim her as a tax dependent. She is eligible for premium tax credits and a cost-sharing reduction. We are not eligible for any subsidies, but we would all like to enroll in the same plan. Can we do that?

You can all enroll in the same family plan, because the ACA requires insurers to offer dependent health coverage to adult children up to the age of 26.
Because you no longer claim your daughter as a tax dependent, she is considered to be in a different tax household from you and will need to file her own federal income tax return.  If she is eligible for premium tax credits based on her income, and if she enrolls as a family member under your Marketplace policy, your daughter can apply her premium tax credit to reduce her share of the premium for that family plan.
However, if she enrolls in your plan, your daughter would lose her eligibility for cost-sharing reductions. If two individuals (or two separate households) qualify for different levels of cost-sharing assistance, or if one qualifies and the other doesn’t, and if they want to be covered under the same plan, they must select a plan that provides the level of cost-sharing reduction that they all would qualify for. In this case, since you do not qualify for any help with cost sharing, the three of you could only enroll together in a plan without cost sharing subsidies.

While we have made every effort to provide accurate information in these FAQs, people should contact the health insurance Marketplace or Medicaid agency in their state for guidance on their specific circumstances.