Originally Posted by MBSC
Creating a unique account for her indicates she is self-sufficient and will not be claimed as a dependent on the parent's tax return. Only her income would be considered and she would be placed into Medicaid if you live in an expansion state. In non-expansion states, she would pay the full premium because her income is below 100% FPL. She would not receive a subsidy if the household income fell since the parent's income is not connected to the account.
This is correct and what I have done for my son who is still living with us, but he makes just enough to be over the 100% FPL threshold so he gets the max credit. It is much cheaper for us to do it this way vs. adding him to our plan as dependent.
Do note that if your child makes close to the min for a subsidy you can still estimate that the income will be above min and if that's accepted by the exchange there is no penalty if income is subsequently below min FPL during the next year. In other words, your child can get full subsidy without penalty as long as the income estimate above min is accepted by the exchange, because when you later file taxes to reconcile the credit there is an exemption for income falling below min as long as you had an accepted exchange filing and an enrolled, paid for plan.