Which retirement plan type must adhere to strict rules, including minimum vesting standards?

The correct answer is that all qualified plans are required to adhere to strict rules, including minimum vesting standards. Qualified retirement plans are those that meet specific requirements set forth by the Internal Revenue Code. These requirements ensure that the plans provide certain protections and benefits to participants, including minimum vesting schedules, which dictate the timeline over which employees earn rights to their benefits in the plan.

Adhering to minimum vesting standards helps protect employees by ensuring they have earned a portion of their benefits after a certain period of service, encouraging long-term employment. This is particularly important in fostering retirement security.

While other plan types, such as defined benefit plans, cash balance plans, and money purchase plans, also have their own parameters and rules, they too fall under the broader category of qualified plans if they meet IRS criteria. Therefore, they must follow the regulations regarding vesting and other requirements. All qualified plans generally share these characteristics, making the answer encompassingly correct.