@AmeliesUncle and I would prefer to identify a IRS or Healthcare.gov source, but this is a non-for-profit website.....
Can a person qualify for a premium tax credit on her own if she could be claimed as a dependent on another taxpayer's return but is not claimed?
No. A person who qualifies as a taxpayer’s dependent cannot claim themselves and so cannot claim the premium tax credit independently. Even if a taxpayer decides or agrees not to claim a dependent, that doesn’t make the dependent eligible to claim herself.
For example, let’s look at Bob, who is caring for his uninsured mother, Marie. Bob provides more than half of Marie’s support and Marie has no income. Marie qualifies as Bob’s dependent. He wants to enroll Marie in a marketplace plan, but Bob’s income is too high to qualify for marketplace subsidies. Even if Bob chooses not to claim Marie as a dependent on his tax return, Marie is not eligible to claim herself on a separate tax return. Because Marie qualifies as Bob’s dependent—whether or not he claims her on his tax return—she cannot qualify for PTC on her own. If Bob claims Marie as a dependent at tax time, any APTC Marie received during the year will be reconciled on Bob’s tax return based on his income and may need to be repaid if his income exceeds 400 percent of poverty.
Any maybe you are reacting to my statement of the "whole thing". Let me clarify.
What I meant was if the dependent files a tax return with form 1095A, and correctly checks the box that they CAN be claimed by someone else, then the entire PTC would have to be repaid. And that would occur whether or not the dependent is actually claimed by someone else.
If the parents file the 1095A form with their tax return (whether or not they claim the dependent), then the repayment is subject to the parent's income, which may or not require repayment.
