 [ Symptoms ] how is income level determined under the terms of obamacare i am retired 63   not yet eligible for medicare [ Disease ] it is your household income – your modified adjusted gross income magi to be specific – that determines whether you will be eligible for a tax credit that lowers the cost of your health insurance or qualify for medicaid starting in 2014 in most cases magi is the same adjusted gross income or agi you can find your agi by looking at your tax return here is where you can easily find the agi depending upon the tax form you use form 1040 ez – line 4 form 1040a – line 22 form 1040 – line 38