The Unclassified Retirement Plan is a defined contribution retirement plan. There are many resources available for employees wanting to learn more about continuing their benefits when they retire.Do you know what it takes to work towards a secure retirement? Use this calculator to help you create your retirement plan. Most Requested Retirement Resources. Once you have a Minnesota ID number and withholding tax account: 1. Have the recipient complete and send Form W-4MNP. 2. Apply for your monthly retirement benefit any time between age 62 and 70. An employee enrolled in the Supplemental Retirement Plan (SRP) is required to make contributions to the Plan through payroll deduction. Learn more about the opportunity with state-facilitated retirement plans.