Similar to social security, a defined benefit plan is a plan where an employee is able to vest a defined retirement benefit, which is achieved by earning a required amount of qualified work history and attaining the necessary retirement age. A member of MEABF normally has earned the right to receive an undiscounted benefit under the following circumstances:

1. 10 years of service at 60 years of age
2. 25 years of service at 55 years of age
3. 30 years of service at 50 years of age