An individual is automatically eligible for Part B if he or she is eligible for premium-free Part A. They are also eligible for Part B if they are not eligible for premium-free Part A but are age 65 or older and a resident of the United States or a citizen or an alien lawfully admitted for permanent residence. In this case, they must have lived in the United States continuously during the 5 years immediately before the month during which he or she enrolls in Part B.