Because of tax incidence. https://en.wikipedia.org/wiki/Tax_incidence https://en.wikipedia.org/wiki/Tax_incidence Just because your employer is the one writing

Because of tax incidence. https://en.wikipedia.org/wiki/Tax_incidence https://en.wikipedia.org/wiki/Tax_incidence Just because your employer is the one writing the checks doesn't mean that the tax burden is really falling on them. The employer side of FICA, for example, is essentially a tax on employee's income.