Method for determining the base
The formula for determining the OASDI contribution and benefit base is set by law. The formula is applicable only if a cost-of-living increase becomes effective for December of the year in which a determination of the base would ordinarily be made. Because there is a cost-of-living increase for December 2014, the formula is applicable. The formula states that the base for any year Y after 1994 is equal to the 1994 base of \$60,600 multiplied by the ratio of the national average wage index for year (Y-2) to that for 1992, with the result rounded to the nearest multiple of \$300. If the result is less than the current base, the base is not reduced.

Base for 2015
Under the above formula, the base for 2015 shall be the 1994 base of \$60,600 multiplied by the ratio of the national average wage index for 2013 to that for 1992, or, if larger, the 2014 base of \$117,000. If the amount so determined is not a multiple of \$300, it is rounded to the nearest multiple of \$300.

Amounts informula Computation 1994 base \$60,600 1992 average wage index 22,935.42 2013 average wage index 44,888.16 \$60,600 times 44,888.16 divided by 22,935.42 equals \$118,603.56, which rounds to \$118,500 \$118,500 exceeds the base for 2014, so the base for 2015 is \$118,500