The problem

One reason that many Americans believe Medicare does not contribute to the deficit is that the majority thinks Medicare recipients pay or have prepaid the cost of their health care. Medicare beneficiaries on average pay about $1 for every $3 in benefits they receive…However, about two-thirds of the public believe that most Medicare recipients get benefits worth about the same (27%) or less (41%) than what they have paid in payroll taxes during their working lives and in premiums for their current coverage.

Here is more, via Amitabh Chandra.