A Social Security tax rate table is available from the official Social Security Administration website at SSA.gov. The rates depicted in the table cover Social Security's Old-Age, Survivors and Disability Insurance program, often referred to as OASDI, as well as Medicare's Hospital Insurance, according to the SSA.
Tax rates for Social Security and Medicare are determined by law and are levied on taxpayers for earnings up to the maximum taxable amount, explains the SSA. As of 2015, the posted tax rate table shows the contribution and benefit bases from 1937 to 2015. It further delineates the amounts owed by employers and employees, as opposed to amounts owed by self-employed workers.