Which type of employer contribution to a 401(k) plan involves a guaranteed payment regardless of employee participation?

The choice of non-elective contributions as the correct answer is based on the fact that these contributions are made by the employer to employees' 401(k) accounts without any requirement for the employees to contribute to the plan themselves. This means that the employer guarantees a certain level of contribution to eligible employees, regardless of whether or how much the employees choose to participate in the 401(k) plan. This attribute ensures that all eligible employees receive a benefit from the employer, which can help encourage broader participation in the plan and can also assist with meeting required plan testing criteria.

Matching contributions and qualified matching contributions, on the other hand, depend explicitly on employee participation. These types of contributions require employees to make their own contributions before the employer adds a matching amount. Therefore, they do not provide the same guarantee of employer contributions to employees who opt not to contribute themselves. Qualified non-elective contributions, while also employer-driven, can be tied to specific eligibility and may not be guaranteed in the same way across the entire employee base. Thus, non-elective contributions stand out in that they provide an assured benefit from the employer without linking it to the employee's personal contributions.