3947 / Are contributions to a qualified plan subject to Social Security taxes?

Amounts that a regular (i.e., common law) employee elects to contribute under a cash or deferred arrangement under IRC Section 401(k), a section 403(b) plan ( Q 3760), and SIMPLE IRA plans are treated as wages subject to Social Security tax.¹ Payments to, from, or under a qualified retirement plan are specifically excluded from the definition of wages under the Social Security law. Consequently, neither employer contributions to, nor distributions from, a qualified retirement plan are subject to Social Security taxes.²