This figure represents active employees, retirees, beneficiaries and deferred members. CCCERA is a contributory defined benefit plan, as mandated by the regulations of the CERL. This plan requires both employers and employees to contribute to the fund. A defined benefit retirement plan does not base future retirement benefits on how much the employee and employer contribute to the fund, nor do fluctuating investment returns play a role in determining final retirement allowances. Rather, a fixed formula, stipulated by the 1937 Act, determines members’ future retirement allowances. Retirement benefits are calculated using three important variables within the following formula: Highest Average Years of Retirement Age at Monthly Salary x Service Credit x Retirement Age Factor As of 2008, CCCERA administers 8 different benefit tiers. All tiers use the above formula, however. Highest Average Monthly Salary is computed using the highest 36 consecutive months of salary for Tier 2 and Safety Tier C members; the highest 12 consecutive months of salary are used for the remaining 6 tiers. Retirement Service Credit corresponds to the length of time a member has worked while actively contributing to the retirement system. Service credit may also comprise time with another ’37 Act County or “reciprocal” agency and may also include time “purchased” as a prior public servant (military service or federal government for example). Retired members are entitled to an annual cost of living (COLA) increase, granted by the Board, effective April 1 of each year. This benefit is based on the San Francisco-Oakland-San Jose area Consumer Price Index and may range up to between 2% and 4%. CCCERA is not responsible for providing health benefits to its members. These are administered by the Human Resources department of Contra Costa County. Known as “Other Post Employment Benefits” (OPEB), the County provides post retirement health benefits for employees who have retired under CCCERA and to the spouses and dependents of these retirees. The County also provides health and dental benefits to active members through contracting with various health and dental plans. Such benefits are established through negotiations between Contra Costa County and the various bargaining units that represent the County's employees. The stipulations of OPEB may be modified, altered or terminated at any time and for any reason as provided in the plan documents. Unlike OPEBs, a CCCERA member's pension is a lifetime benefit. As of 2012, it has significant underfunding liabilities in excess of $1.9 billion.