Health insurance is not mandatory for expats living in the US, although with medical costs being so exorbitant, it is certainly desirable. Government healthcare, such as Medicaid and Medicare, is available for only those US citizens and expats that meet certain criteria (they have to make under a certain amount of money). Most people are not eligible to receive government healthcare, and are either insured through their employer or buy private healthcare insurance on their own). Employers are not obligated to provide health insurance, but most companies do provide some sort of health benefits for full-time employees. There are also several international insurance companies that provide insurance for expats around the world through which you may purchase a private policy. Please note that in general expats do not have to carry health insurance when coming to the US, although many colleges and universities require their students to have some sort of insurance when they enroll.