Furthermore, individuals and businesses subject to social insurance taxes are subject to them as a byproduct of their decision to enter covered employment or engage in a covered business, so especially for the major, broad-based social insurance programs--Social Security, Medicare (hospital insurance), and unemployment
As byproducts, individuals and businesses subject to social insurance taxes are subject  to their decision to enter covered employment.  
As byproducts,  individuals and businesses subject to social insurance taxes are never subject to their decision to enter covered employment.  