Cal. Gov. Code § 31672.5
Notwithstanding any other provision of this chapter, when any member of a retirement system of any other public agency becomes a member of a county retirement association, established pursuant to this chapter, as a result of the transfer to and assumption by the county of any function of the other public agency, and the member retains rights in the retirement system of the other public agency in respect to service theretofore rendered to that agency, such member shall be eligible for retirement under the county retirement system at any time at which he would have been eligible for such retirement if the service rendered to the other public agency had been rendered instead to the county. A certificate of any officer of the other public agency authorized to determine service rendered to that agency that certain service was rendered to such agency shall be accepted by the retirement board of the county retirement association as prima facie evidence of service so rendered.
This section shall be applied only to enable such members of county retirement systems to qualify for retirement. Nothing in this section entitles any member of a county retirement system to any pension or other benefit based upon service rendered to any other public agency, but such a member upon his retirement shall be entitled to a retirement allowance under the county retirement system, calculated according to the formula applicable under such system, and on the basis of his county service even though such service be less than the minimum county service required for retirement under such system. The provisions in this chapter for minimum retirement allowances, shall not apply to any retired person who would not have qualified for retirement without including under this section service rendered to such public agency, nor shall such provisions apply unless the sum of the retirement allowances to which such person is entitled under the county retirement system and the retirement system of the other public agency, is less than the otherwise applicable minimum allowance under such provisions.
This section shall become operative in any county on the first day of the calendar month after the board of supervisors adopts by four-fifths vote a resolution making it operative in the county.
Ca. Gov. Code § 31672.5