This site has been designed for eligible Pima County employees. Members can retire with a lifetime benefit as early as age 50 once they have acquired 5 years of service credits.This handbook is designed to help you make important decisions and complete the steps for retiring from the University of Arizona. Retirement System (ASRS) applicable contribution rates for retirement and LTD Benefits. An Eligible Employee must contribute to. More information about Retirement programs are available at the Employee Service Center Intranet page. Step 1: Learn the calculation. The formula to calculate a retirement is quite simple. Unless otherwise stated, the Merit System Rules shall apply to all positions and employees in the classified service within Pima County Government. This webpage will help you manage this change and retire on your own terms.