Millions of retired and disabled people in the United States had better brace for another year with no increase in Social Security payments. The government is projecting a slight cost-of-living adjustment for Social Security benefits next year, the first increase since 2009. But for most beneficiaries, rising Medicare premiums threaten to wipe out any increase in payments, leaving them without a raise for a third straight year. About 45 million people - one in seven in the country -- receive both Medicare and Social Security. By law, beneficiaries have their Medicare Part B premiums, which cover doctor visits, deducted from their Social Security payments each month. When Medicare premiums rise more than Social Security payments, millions of people living on fixed incomes don't get raises. David Certner of AARP estimates that as many as three-fourths of beneficiaries will have their entire Social Security increase swallowed by rising Medicare premiums next year.