California Code, Government Code - GOV § 31727.4

Upon retirement of any member for service-connected disability, he shall receive an annual retirement allowance payable in monthly installments, equal to one-half of his final compensation.  Notwithstanding any other provisions of this chapter, any member upon retirement for service-connected disability shall receive a current service pension or a current service pension combined with a prior service pension purchased by the contributions of the county or district sufficient which when added to the service retirement annuity will equal one-half of his final compensation, or, if qualified for a service retirement, he shall receive his service retirement allowance if such allowance is greater but in no event shall it exceed the limitation as set forth in Section 31676.1 as it now reads or may hereafter be amended to read.  The provisions of this section shall also apply to any employee who becomes disabled for service-connected causes prior to the first day of the calendar month when he would normally become a member.