Green card holders who do not qualify for Medicare will qualify for Obamacare and any relevant federal subsidy. They may also qualify for Medicaid, depending upon their location.
One needs to have worked a total of 40 quarters (10 years) in the United States to qualify for Medicare.
U.S. citizens and lawful permanent residents at least age 65, who have been here five years, may buy into Medicare if they don’t have the work history. Individuals who qualify to buy-in to Medicare can choose to participate in Medicare or buy Obamacare insurance.
Those qualified for “premium free” Medicare or Medicaid do not qualify for Obamacare.
Geography matters when it comes to Medicaid, “a need-based health insurance program for individuals with little or no income. In some states, including South Carolina, you cannot get full Medicaid until you have been a permanent resident for five years. You can however, get Medicaid reimbursement for emergency services. In some states, including New York, all permanent residents who meet the income qualifications can get Medicaid.”