(case brought by retired federal employees seeking to opt out of Medicare Part A so that they could utilize the health insurance plan available to federal employees; federal law and defendant's corresponding regulations require Social Security recipients age 65 and older to enroll in Medicare; while court noted that Medicare costs are skyrocketing and "may bankrupt us all," court's hands were tied in that participation was statutorily mandated; court noted that even if opt out was allowed, plaintiffs would not receive greater benefits than that offered by Medicare; court reasoned that the Congress intended for Medicare to be a mandatory benefit by linking coverage with retirement benefits; court opined that plaintiffs' arguments had merit, but that court could not find any statutory way out of Mandatory participation in Medicare or requirement that government provide a means for opting out; court did note that plaintiffs could escape the Medicaid program by forfeiting all Social Security benefits past, present and future).