As a general rule California cannot tax retirement benefits that you receive when you are no longer a resident of California. Prior to 1996, the state of CA did exactly that.
PL 104–95 was enacted by Congress that year to prohibit the so called taxation based on source of earnings.
There are some deferred compensation plans not covered, but the following are covered by this law:
(A) a qualified trust under section 401(a) of the Internal Revenue Code of 1986 that is exempt under section 501(a) from taxation;"
(B) a simplified employee pension as defined in section 408(k) of such Code;"
(C) an annuity plan described in section 403(a) of such Code;"
(D) an annuity contract described in section 403(b) of such Code;"
(E) an individual retirement plan described in section 7701(a)(37) of such Code;"
(F) an eligible deferred compensation plan (as defined in section 457 of such Code);"
(G) a governmental plan (as defined in section 414(d) of such Code);"
(H) a trust described in section 501(c)(18) of such Code; or"
(I) any plan, program, or arrangement described in section 3121(v)(2)(C) of such Code, if such income—"(i) is part of a series of substantially equal periodic payments (not less frequently than annually) made for—"(I) the life or life expectancy of the recipient (or the joint lives or joint life expectancies of the recipient and the designated beneficiary of the recipient), or"(II) a period of not less than 10 years, or"(ii) is a payment received after termination of employment and under a plan, program, or arrangement (to which such employment relates) maintained solely for the purpose of providing retirement benefits for employees in excess of the limitations imposed by 1 or more of sections 401(a)(17), 401(k), 401(m), 402(g), 403(b), 408(k), or 415 of such Code or any other limitation on contributions or benefits in such Code on plans to which any of such sections apply.