Final answer:
A 408(k) refers to a SEP IRA, a type of retirement plan that allows employers and self-employed individuals to make retirement contributions that are tax-deferred and portable.
Step-by-step explanation:
The type of qualified plan a 408(k) refers to is a Simplified Employee Pension Individual Retirement Arrangement, known as a SEP IRA. Unlike 401(k)s and 403(b)s, which are set up by employers, SEP IRAs can be set up by both employers and self-employed individuals, allowing them to contribute a fixed amount to their retirement on a regular basis. These contributions are tax-deferred, and the SEP IRA is portable, meaning it can follow an employee even if they change jobs, similar to 401(k) plans. SEP IRAs are an attractive option due to their simplicity and higher contribution limits compared to traditional IRAs.