MIT requires most affiliates to have comprehensive health insurance. In addition, if you are an affiliate with a J-1 visa, the U.S. Department of State requires that you (and all your family members with J-2 visas) have health insurance that meets specific requirements. You must buy this insurance within 30 days of your arrival, and you must continue this coverage until you leave the United States.
But don’t just think about meeting the requirements. You should also think about the kind of coverage you want and need. If you become sick or get hurt during your time in Cambridge, how will you pay for the medical care you need? You may have already purchased insurance to meet visa requirements, but is it enough?