Dylan Matthews balances Social Security by lifting the contribution cap:

Currently, wages over a certain yearly total ($106,800 this year) are exempted from Social Security payroll taxes. Medicare's payroll tax has no such cap. This has raised the question of how raising the cap could extend Social Security's solvency....Congressional Research Service looked at this question in 2008 by evaluating three different proposals. The first would raise the cap so that 90 percent of wages are taxed (CRS estimates this would mean a cap of $171,600 in 2006) and pay higher benefits to those affected; the second would eliminate the cap and pay higher benefits; and the third would eliminate the cap for taxes but would not increase benefits...]]>