The retirement plan of the Minnesota Department of Corrections ("DOC"), under its collective bargaining agreement, had an early retirement incentive. It provided that a plan participant who retired during the pay period of his or her 55th birthday, in general, was eligible for an unreduced continuation of the employer's contribution towards his or her health and dental retirement plan until he or she reached 65. The DOC argued that this plan was not discriminatory and was permitted under the provision allowing terms of bona fide employee benefit plans to continue so long as they are voluntary and consistent with the relevant purposes of the ADEA. Moreover, they argued that this was a fair plan because under Federal law they were authorized to retire their employees at age 55. As an employee's eligibility for this attractive early retirement benefit vanishes when the employee reaches 55, this so-called cliff is arbitrary age discrimination. The benefit is based solely on age, and the other argument concerning mandatory retirement is irrelevant as the employees are not required to mandatorily retire. EEOC v. Minnesota Department of Corrections (8th Cir. 2011).