Who is eligible to buy health insurance through the Affordable Care Act / Obamacare exchanges?

The only one requirement / eligibility is that you must be a US Citizen or be a lawfully legal resident (qualify non-citizen) of United States.  Only illegal residents are not qualify to purchase health insurance through the health exchanges.

The term “qualified non-citizen” includes:

• Lawful Permanent Residents (LPR/Green Card Holder)
• Asylees
• Refugees
• Cuban/Haitian entrants
• Paroled into the U.S. for at least one year
• Conditional entrant granted before 1980
• Battered non-citizens, spouses, children, or parents
• Victims of trafficking and his or her spouse, child, sibling, or parent or individuals with a pending application for a victim of trafficking visa
• Granted withholding of deportation
• Member of a federally recognized Indian tribe or American Indian born in Canada