Medicare and Medicare supplement insurance is available to individuals under 65 who are disabled and have received Social Security disability benefits for 24 months, automatically qualifying them for parts A and B. While under 65, individuals can enroll in Medicare supplement plans without medical underwriting for six months after starting Medicare Part B, with coverage varying by state. In at least 25 states, at least one Medigap plan is available for those under 65, though availability may differ among states.