I am having a similar issue and want to make sure that I am doing this correctly. The definition of compensation is W2 compensation; nothing is excluded from the of W2 compensation. Box 1 wages if $155,860.89; and Box 3 and 5 are $159,011.47. The S Corp health insurance is $20,359.42, the salary deferral is $23,500; and the Roth deferral is $11,250. If I am reading all this correctly, then the compensation that I am using for plan purposes calculations is $179,360.89. $155,860.89 + $23,500.