As longtime union/CalPERS members, a couple of clarifications:
1) Unlike most states, participation in CalPERS is voluntary. All public agencies are eligible to join, but many do not. San Francisco City/County, for example, self-funds; they are not and never have been, CalPERS members.
2) Retirement benefits and healthcare benefits are separate under CalPERS. IOW, a public agency may decide to self-fund retirement but participate in CalPERS healthcare.
3) At least 3x in the past 30 years the CA State Legislature has [legally, unfortunately] "raided" the CalPERS fund to balance the state budget. It justifies doing so, in their eyes, any time the CalPERS fund goes above 100% - rather than leaving the excess to make up for the years when ROI is below expectations.
4) EVERY agency has its own different formulas and eligibility criteria for retirement benefits. The formula my Spouse retired under, was different than his BART police friend or even his manager.
5) It is up to the INDIVIDUAL agency to fund retirement health benefits, IF they have signed a union agreement to provide them (most do not). The majority who have promised, are like most public pension funds: they push it off and only fund current claims. We were surprised, actually, when during one contract year, Spouse's union got management to agree to assessing workers and management a monthly fee to set up a separate funding for retirement healthcare. The fee has gone up over the years, but thanks to starting it several decades prior, it remains a reasonable charge spread across all employees, whether current or retired, who signed up for the retirement healthcare option.
CalPERS pensions are not as big (on average) as most people think they are. This is because many people are not agency "lifers", i.e.; they have worked in private industry or at other agencies in different states, before joining a public agency that participates in CalPERS. They will retire usually with 10-15 yrs of a CalPERS pension. Assuming the usual average of 2% per year of service, the pension would be 20%-30% of salary, as determined by the agency's union contract. It might be based on the last three or five years, or based on the highest salary in any three years, or any other contractual limitation.
Below are the official pension averages. You notice they make the same mistake most make; they lump CalPERS and CalSTRS together. School districts can join CalPERS; but well over 90% of them do not.
The reason is simple: CalPERS charges a higher premium to administer an agency or district. CalSTRS is cheaper, which is also why it is in more financial difficulty:
"The average CalPERS pension benefit for all service retirees is $42,516 annually, or roughly $3,500 per month. This is a general average, and individual benefits vary based on factors like years of service, salary history, and retirement plan chosen. For example, state retirees (CalPERS) average $4,133 monthly, while school retirees (CalSTRS) receive $2,038 monthly on average. "
Note that CalSTRS has more serious underfunding than CalPERS. That has been true as long as my Spouse was working, and he retired 15 yrs ago with 42 yrs of service.