Which of the following contributions are not taxed at the time they are made to a 401(k) plan?

Contributions to a 401(k) plan have specific tax implications that are crucial for both employers and employees to understand. Generally, traditional pre-tax contributions are not taxed at the time they are made. Instead, these contributions reduce the employee's taxable income in the year they are made, allowing for immediate tax benefits. Taxes on these contributions are deferred until the individual withdraws funds during retirement.

On the other hand, Roth contributions are made with after-tax dollars, meaning that taxes are paid at the time of contribution. This allows for tax-free withdrawals during retirement, provided certain conditions are met. Similarly, after-tax contributions also involve taxes being paid upfront.

Considering this, the correct answer states that all contributions, except Roth and after-tax contributions, are not taxed at the time they are made. This accurately reflects the tax treatment of traditional pre-tax contributions, which allow for a tax-deferred advantage. Understanding this distinction is essential for effective tax planning and maximizing retirement savings.